Charging an EV /w an off-grid solar panel set up?

gww1 · October 2014

Re: Charging an EV /w an off-grid solar panel set up?

coot
some times things circle in my head making them harder to see then it should be. Light bulb has went off so thanks for your and every one elses patiants. Thats right I can't spell either.
Thanks
gww

BB. · October 2014

Re: Charging an EV /w an off-grid solar panel set up?

One thing to remember is that at higher charge/discharge rates, Lead Acid batteries tend to be less efficient.

We use C/20 hour discharge rate as our "capacity" (i.e., 12 volt at 100 AH).

If you discharge at 100 AH / 20 hour rate = 5 amps (100-0%--to dead battery), you will get 100 AH.

If you discharge at C/5 rate, you may only get 80 AH of capacity--The Peurkert effect. The battery appears to only have 80 AH of capacity at C/5 hour (100/5=20 amp) discharge rate.

-Bill

lolcashcow · October 2014

Re: Charging an EV /w an off-grid solar panel set up?

solar_dave wrote: »

OK again the problem with 6 amp charge rate is the 15 hours of time, your solar will only produce power about 4 hours of sun equivalent time per day. The reference I made previously to DCFusor is an opportunity load. He uses an L2 ESEV and it will charge his Volt in a few hours assuming he has the excess power from his Solar system after the house batteries are charged. The key to charging off solar would be to have enough input over a short enough time.

Excess power, but what about excess time? I would be camping after all, so I would have excess tiime on my hands

. camping for a single day is too short in my opinion. I could easily camp at least for 4 days. That would be 4 hours of solar charging per day for 4 days 4*4=16. There! We got the EV recharged back to full! That charge time of 15 hours would also be reduced based on how much I drained the battery to begin with, right? What if I only used 50% of the battery to get there? 15-50%=7.5 hrs to charge. Now recharge time has been been reduced to half the time. In other words two days. Any time after that would just be some extra money in the bag. This could really apply to someone who is retired, like a retired vet, or a camper, or even someone who just decides to live in an EV Van. I see a lot of people doing it here in LA; in their fuel burners. What do you guys think? Some kind of hip urban set up?

http://www.designclaud.nl/wp-content/uploads/2013/07/VW-van-01.jpg

Cariboocoot · October 2014

Re: Charging an EV /w an off-grid solar panel set up?

Trying to spread charging out over a matter of days can lead to problems, but that is based on lead-acid batteries not lithium ones. For example if they are below 70% SOC for the first couple of days you'll get a shortening of lifespan. If you used LiFePo and charged them up over time and had enough capacity to then charge the EV on the last day this would work better (albeit at greater expense). And of course if you could access the EV batteries directly again the problem would solve itself: reduce efficiency losses considerably and put back over time the power needed without taking any out in the interim.

That last bit will always be with you if you use a secondary bank to store up power for recharging the EV, even if it is connected for charging all the time; the secondary bank will be charged/discharged daily as the power is transferred from PV to charging bank to EV.

And you know one day's running of a EU2000i would do the job faster, more efficiently, and for far less money.

The biggest boon to the industry would be to get PV efficiency up above 50% instead of at the sad 20% it's at. But so far all the 'breakthroughs' is panel tech seemed to be about solving problems that don't actually exist like making them transparent or paint-on or in different flavours.

lolcashcow · October 2014

Re: Charging an EV /w an off-grid solar panel set up?

Cariboocoot wrote: »

Trying to spread charging out over a matter of days can lead to problems, but that is based on lead-acid batteries not lithium ones. For example if they are below 70% SOC for the first couple of days you'll get a shortening of lifespan. If you used LiFePo and charged them up over time and had enough capacity to then charge the EV on the last day this would work better (albeit at greater expense). And of course if you could access the EV batteries directly again the problem would solve itself: reduce efficiency losses considerably and put back over time the power needed without taking any out in the interim.

That last bit will always be with you if you use a secondary bank to store up power for recharging the EV, even if it is connected for charging all the time; the secondary bank will be charged/discharged daily as the power is transferred from PV to charging bank to EV.

And you know one day's running of a EU2000i would do the job faster, more efficiently, and for far less money.

The biggest boon to the industry would be to get PV efficiency up above 50% instead of at the sad 20% it's at. But so far all the 'breakthroughs' is panel tech seemed to be about solving problems that don't actually exist like making them transparent or paint-on or in different flavours.

Gosh, I really wish I could just use the batteries in the car. It would solve so many problems. Out of all the items required, which would be the most expensive? Is it the 2,000w inverter? Or getting about 700 to 800 watts worth of solar panels? You also need an MPPT controller, but what if you bought a large 800 watt solar panel? Though I am not sure just how big it would be, perhaps too large actually to fit inside the van. The battery bank does not seem so bad. Someone mentioned 2 though more would be best, correct?

Cariboocoot · October 2014

Re: Charging an EV /w an off-grid solar panel set up?

The batteries are the big expense. Whether you pick lead-acid or LiFePo you would be shelling out a considerable amount of money in order to have enough stored capacity to replace the energy in the run-down EV battery.

Otherwise you're looking at about $1,000 in panels and probably $500 for an MPPT controller. Right there you have the cost of a generator. Add an inverter capable of even the small output demand and you've gone about $2,000 even without batteries. Actual prices will of course depend on the exact components selected and where you buy them.

But as a rule off-grid power is had at a significant cost, and that cost is higher the less it is used. For just charging an EV from time to time it would be huge per kW hour, especially with 100% needing to go in and out of another battery set to begin with.

Yes if you could connect directly to the EV battery you could save a lot of money: PV & charge controller and you're done. But matching it up becomes an engineering challenge and without the manufacturer of the EV approving the warranty is instantly void.

lolcashcow · October 2014

Re: Charging an EV /w an off-grid solar panel set up?

Cariboocoot wrote: »

The batteries are the big expense. Whether you pick lead-acid or LiFePo you would be shelling out a considerable amount of money in order to have enough stored capacity to replace the energy in the run-down EV battery.

Otherwise you're looking at about $1,000 in panels and probably $500 for an MPPT controller. Right there you have the cost of a generator. Add an inverter capable of even the small output demand and you've gone about $2,000 even without batteries. Actual prices will of course depend on the exact components selected and where you buy them.

But as a rule off-grid power is had at a significant cost, and that cost is higher the less it is used. For just charging an EV from time to time it would be huge per kW hour, especially with 100% needing to go in and out of another battery set to begin with.

Yes if you could connect directly to the EV battery you could save a lot of money: PV & charge controller and you're done. But matching it up becomes an engineering challenge and without the manufacturer of the EV approving the warranty is instantly void.

How many golf cart batteries are we looking at? Someone mentioned only getting 2 before. I actually have never checked on how much each of these cost, but they cannot be near $1,000? My guess would be... 200 - 300? Would that be New or Used? At least from your guy's experence in buying them, I mean.

Cariboocoot · October 2014

Re: Charging an EV /w an off-grid solar panel set up?

Cost would be a function of how much you want to recharge how fast. This would be from full recharging potential all in one day to raising the EV charge level by whatever you can over however long you're parked. As you can guess the first scenario would be the most expensive as it would need to harvest and store the total Watt hours requirement (including losses) in one day of maybe 4-5 hours good sun. The last would be cheapest to construct, but since it would be a case "whatever you get, you get" it may not be worthwhile to do.

We could write up three system design ideas based on powering a given AC charger, but it would take some time to do.

lolcashcow · October 2014

Re: Charging an EV /w an off-grid solar panel set up?

Cariboocoot wrote: »

Cost would be a function of how much you want to recharge how fast. This would be from full recharging potential all in one day to raising the EV charge level by whatever you can over however long you're parked. As you can guess the first scenario would be the most expensive as it would need to harvest and store the total Watt hours requirement (including losses) in one day of maybe 4-5 hours good sun. The last would be cheapest to construct, but since it would be a case "whatever you get, you get" it may not be worthwhile to do.

We could write up three system design ideas based on powering a given AC charger, but it would take some time to do.

Hii Cariboo,

This is more of a future project than anything. The Nissan E-NV200 has not even been released out in the US yet. Though it is available in japan and the UK. Therefore I got some time to save up cash and prepare the project. I got another question though. The battery the EV uses is it similar to a regular car battery? I mean, if you want try and use the EV battery you have to go through the charging port to do it, but what if you just use the battery itself , and use the battery alone with your solar panel set up? From what I have read online the E-NV200 is going to use the same battery as the Nissan leaf, so we can use that as a base. What I mean is disconnecting the battery from the car and using it as it were a regular car battery. Not possible? I mean, at least with old gas cars we used to be able to just take out the battery and use it? I wonder if the battery is deep cycle? I mean, it has to power the car for prolonged periods of time.... I don't mean going through the charging port, is it not possible to hook it up and use it like a deep cycle battery?

http://www.nissanusa.com/electric-cars/leaf/charging-range/battery/

The 24kWh lithium-ion battery stores its energy to power the 80 kW AC motor in 48 lithium-ion modules. Each module contains four lithium-ion battery cells and provides enough power to the motor to generate 187 lb-ft of torque off the line, and 107 horsepower.

lithium-ion? I recharge lithium-ion batteries all the time! (Sorry guys, I just had to say it. I found it so hilarious at this point.)

http://en.wikipedia.org/wiki/Nissan_Leaf#Battery

In addition to the main battery, the Leaf also has an auxiliary 12-volt lead–acid battery that provides power to the car computer systems and accessories such as the audio system, supplemental restraint systems, headlights and windshield wipers.[41] The small solar panel on the Leaf rear spoiler (noting that in the United States models, only comes with SL trim[42]) helps to charge this accessory battery.[43]

Found some detailed specs on the battery:

www.electricvehiclewiki.com/?title=Battery_specs

Battery Specs
Type Laminated lithium-ion battery
Voltage 403.2V [1]
Nominal voltage 360V [2]
Total capacity 24 kWh [2] (16 kWh available, 67% DoD [3], 21 kWh declared [4])
Power output Over 90 kW
Energy density 140 Wh/kg [5]
Power density 2.5 kW/kg [5]
Dimensions 61.8 x 46.8 x 10.4 in. (1570.5 x 1188 x 264.9 mm) [1]
Weight 648 lbs [6]
Number of modules 48, each with four cells (total 192 cells) [7][2]
Battery pack contents:

Positive electrodes: lithium manganate
Negative electrodes: carbon
Cells
Modules
Assembly parts

Charging times:

Quick charger DC50kW (0 to 80%): approx. 30 min (Level 3 charging)
Home-use AC240V charging dock (0-100%): 8 hrs (Level 2 charging) [8]
Regular 110/120V 15-amp outlet: 22 hours (Level 1 charging) [9]

Battery layout Under seat & floor

Battery module specs[2]
Number of cells 4
Construction 2 in-series pairs in parallel
Length 11.9291" (303 mm)
Width 8.7795" (223 mm)
Thickness 1.3779" (35 mm)
Weight 8.3775 lbs (3.8 kgs)
Output terminal M6 nut
Voltage sensing terminal M4 nut
Module fixing hole diameter 0.3582" (9.1 mm)

Cell specs[2]
Cell type Laminate type
Cathode material LiMn2O4 with LiNiO2
Anode material Graphite
Rated capacity (0.3C) 33.1 Ah
Average voltage 3.8 V
Length 11.417" (290 mm)
Width 8.504" (216 mm)
Thickness 0.2795" (7.1mm)
Weight 1.7624 lbs (799 g)

48 x4.2V so it should be about 196V nominal or so.

24kWh total means each of those 4 limn pouches is 125Ah capacity. notice no special cooling as used on Volt. looks like it is an integral battery case, which along with the floorpan adds strength as a tubular member.

LITHIUM BATTERY MODULE LiMn2O4/LiNiO2 @ $119.00 usd a piece.

http://www.hybridautocenter.com/HAC4/index.php?option=com_hikashop&ctrl=product&task=show&cid=3&name=nissan-leaf-battery-module-model-2012-new&Itemid=605

So it looks like you can buy each battery individually at a cheap price. If we could just charge the spare battery directly could we not jus swap it for the drained one in the car? Sorry, just kind of tossing ideas around.

Cariboocoot · October 2014

Re: Charging an EV /w an off-grid solar panel set up?

If the battery bank is small enough and light enough that you can "carry a spare" you wouldn't even need to bring along charging equipment, just a spare charged battery. Like hauling jerry cans of gas but without the mess. This would also be the cheapest option.

Note that 360 Volt nominal Voltage: not the usual DC levels we see in OG applications. But if it is comprised of lower Voltage modules in series then they could be recharged in segments, although keeping them balanced then can be an issue.

This project is a lot of "it all depends" answers.

lolcashcow · October 2014

Re: Charging an EV /w an off-grid solar panel set up?

Cariboocoot wrote: »

If the battery bank is small enough and light enough that you can "carry a spare" you wouldn't even need to bring along charging equipment, just a spare charged battery. Like hauling jerry cans of gas but without the mess. This would also be the cheapest option.

Note that 360 Volt nominal Voltage: not the usual DC levels we see in OG applications. But if it is comprised of lower Voltage modules in series then they could be recharged in segments, although keeping them balanced then can be an issue.

This project is a lot of "it all depends" answers.

Ah, I see what you mean. I could just bring a couple of pre-charged batteries to make a 'round trip'? The listed weight for each battery is 8.3775 lbs. The car has a total of 48 so 402.12lbs. I've read on the internet that the battery weights around 850lbs, but the total listed in my previous post is only 648lbs which should be more accurate.

So well that is too heavy to carry unless I use some type of small cart, or something. How would I charge so many at once? This would be at home through the regular home outlet? Lv1 charging in other words? Well, they are wired in a series inside the car from the pictures I saw online. I guess I would have to do the same? It would still be nice to charge them / at this point use them with the solar panel set up. I would not even have to get myself a deep cycle battery and I was given a pair of solar panels by a friend which is helpful. All I'd need would be the MPPT controller and the Inverter. That would be significantly less than what it was going to be originally!

Cathode material LiMn2O4 with LiNiO2
Anode material Graphite
Rated capacity (0.3C) 33.1 Ah
Average voltage 3.8 V

http://www.hybridautocenter.com/HAC4/index.php?option=com_hikashop&ctrl=product&task=show&cid=3&name=nissan-leaf-battery-module-model-2012-new&Itemid=605

You mentioned the minimal voltage at 360 per the previous post, but well, the one that can be bought online has a voltage of 3.8v? Could it just be a newer battery?

http://www.powerstream.com/lithuim-ion-charge-voltage.htm

What usual DC levels we see in OG applications? Less than 360? Could it become a problem if this one is too high?

Cariboocoot · October 2014

Re: Charging an EV /w an off-grid solar panel set up?

You'd be swapping out a whole battery set, not just one or two modules. But as modules you'd have an easier time moving them (one 8 lbs. unit at a time). Pain in the anatomy to wire them up, but as an integral unit you've got 400 (or more lbs.) to deal with. A GC2 weighs about 64 lbs. and for any practical application of them you'd probably need four: 256 lbs. Plus inverter, charge controller, panels, and misc. wiring & hardware. This is like 'bring a trailer' time no matter which way you go.

A separate set of car batteries could be charged at home in the car, taken out and set aside. These don't suffer from the self-discharge and low SOC issues of lead-acid, so it would be ready to go if made ready in a reasonable time before the trip.

The problem with charging them from solar is getting the specs aligned. As one monolith battery pack they are too high a Voltage for typical controllers to handle. As individual cells they are too low. Somewhere in between they add up to near enough to a standard RE Voltage to work. This would mean either many separate solar set-ups or switching between units as they charge.

But why bother if you can just bring your "spare tank of electricity" with you?

lolcashcow · October 2014

Re: Charging an EV /w an off-grid solar panel set up?

Cariboocoot wrote: »

You'd be swapping out a whole battery set, not just one or two modules. But as modules you'd have an easier time moving them (one 8 lbs. unit at a time). Pain in the anatomy to wire them up, but as an integral unit you've got 400 (or more lbs.) to deal with. A GC2 weighs about 64 lbs. and for any practical application of them you'd probably need four: 256 lbs. Plus inverter, charge controller, panels, and misc. wiring & hardware. This is like 'bring a trailer' time no matter which way you go.

A separate set of car batteries could be charged at home in the car, taken out and set aside. These don't suffer from the self-discharge and low SOC issues of lead-acid, so it would be ready to go if made ready in a reasonable time before the trip.

The problem with charging them from solar is getting the specs aligned. As one monolith battery pack they are too high a Voltage for typical controllers to handle. As individual cells they are too low. Somewhere in between they add up to near enough to a standard RE Voltage to work. This would mean either many separate solar set-ups or switching between units as they charge.

But why bother if you can just bring your "spare tank of electricity" with you?

I see, then the golf cart option would be the lightest when compared with the complete EV battery set. Since these are lead-acid and I would be keeping them with me in the car how safe are the Hydrogen and sulphuric acid fumes to breathe in? From what I saw online after, doing a quick search, Lithium ion batteries don't give out fumes unless I skipped anything important....

So in terms of getting the specs aligned... trying to hook up the complete Nissan Leaf battery set to the solar panel set up is very difficult since the total voltage will be too high, and when trying to charge a single cell the voltage ends up too low. RE Voltage stands for a Voltage Regulartor Device? I wasn't too sure of the meaning behind that and ended looking online. If I am right (Not sure at all) then we will need to add some kind of voltage regulator gadget?

When you say that (as an individual cell) the voltage will be too low to use that means that the voltage is too low to align to any conventional solar panel? Meaning not enough electricity comes in to move the chemistry inside the battery? Sorry for the question I'm just trying to understand why too low of a voltage would not work.

However, since we are now able to pick and total out a voltage this means it should be ... significant'y easier than when we first started this thread wouldn't

? Hopefully? I mean, by passing the charging port of the car as when done in regular charging?

Out of the two options you mentioned at the end "This would mean either many separate solar set-ups or switching between units as they charge." It sounds like the easiest would be to just switch between units as they charge. So it would be a set of batteries, but not the complete battery (Because of voltage is too high for that). Doing many separate solar set-ups sounds difficult to me. Though you guys are the experts here so I will wait for a response

.

Thank you guys!

Cariboocoot · October 2014

Re: Charging an EV /w an off-grid solar panel set up?

RE = Renewable Energy. The standard nominal system Voltages of 12, 24, or 48 as opposed to the EV's 360 Volts.

The fume hazard from flooded cells is sometimes exaggerated. The acid mist stays near the batteries (and corrodes connections) and the hydrogen and oxygen float away. The latter becomes more of a problem in an enclosed space where levels can build up. The sulphur in the acid mist stinks. The ultimate solution here is AGM batteries; no fume problems and not as expensive as LiFePo. They can also take greater current than flooded cells, which eases the battery-to-PV ratio issue.

So one option would be roughly 200 Amp hours @ 24 Volts of AGM with a 1kW sine inverter to power the AC charger and about 1500 Watts of PV to back it up. While the sun shines the PV will produce the 960 Watts the AC charger needs, so you might get 4-5 hours of EV charging. It would be important to not run the charger when the PV is not producing sufficient Watts. A little manual monitoring should handle that. The AGM batteries then could handle a sudden 'no load' jolt of near 50 Amps if that should occur (25% rate, not sustain because most of the time the current from the panels would be going to the EV charger via the inverter. Flooded cells would not like that current should it happen).

Let's look at some 'real' numbers (trying to keep price and equipment minimal) based on needing to power that 8 Amp @ 120 VAC 960 Watt charger:
Small inverter to handle the charger load; Samlex 1500 Watt 24 Volt $500
200-ish Amp hours @ 24 Volts AGM batteries; two Sun Xtender PVX-1040T $600 (132 lbs.)
60 Amp MPPT controller; Outback FM60 $500
Enough PV to provide power (1200 Watts average) while sun shines; six KD250 Watts $1542

That would run the charger while the sun shines and cost about $3,500 (including misc. bits).
You would not want to deplete the batteries with this; they are there to stabilize the PV output to inverter input. Otherwise at 50% DOD you'd get about 2kW hours out of it. Biggest problem here is the large array size.

Makes the Honda EU2000i look like quite a bargain.

Cariboocoot · October 2014

Re: Charging an EV /w an off-grid solar panel set up?

BTW if you want to reduce the PV you can also build a system to purposefully cycle the batteries, charging during daylight and discharging to the EV afterwards. Just another way of achieving the same end. I'm not sure it would work any better - or worse.

lolcashcow · October 2014

Re: Charging an EV /w an off-grid solar panel set up?

Cariboocoot wrote: »

BTW if you want to reduce the PV you can also build a system to purposefully cycle the batteries, charging during daylight and discharging to the EV afterwards. Just another way of achieving the same end. I'm not sure it would work any better - or worse.

I see what you mean. That Honda EU2000i woulld be more than enough for what I am thinking of and still have some to spare. Can't quite hit the Lv2 charging level though (240 volt, 20 amp). Would need 2 and a half units for that? It gives 2,000w per hour?

I think the biggest problem is the amount of solar panels that are needed. 1,500 watts worth of solar panels is a lot! I have x2 170w panels and thinking that I would have to bring 9 of those with me is crazy! At least inside a small EV that is not a wise idea. I would prefer not to tow a trailer either. Though half that amount seems feaseable 750w. In other words 4.4 panels. well, that means 5. I would prefer 4, but my guess is that in the end I'd only be able to charge the EV for 1 hour once the day is over?

So I see we can use AGM batteries which is the idea I had for an ealier solar panel set up. However, would it be possible to use a couple of batteries from the EV as I mentionoed earlier? What kind of challenges would we be looking at? It was mentioned that trying to use a single EV cell would not be enough, and trying to use them all would not be practical because of the voltage needed. So about how many would be the sweet number that could make it possible? Would we need a special connectorr? They don't look quite like marine/car batteries from what I saw on the website.

From what I saw on the website it has 3 connectors. Is it negative, positive, and ground?

http://www.hybridautocenter.com/HAC4/index.php?option=com_hikashop&ctrl=product&task=show&cid=3&name=nissan-leaf-battery-module-model-2012-new&Itemid=605

Cariboocoot · October 2014

Re: Charging an EV /w an off-grid solar panel set up?

The small Honda's could be rigged to provide the high charging level, but it would involve two of them plus a 4kVA transformer to get the Voltage. Might as well just buy one larger gen capable of 5kW to begin with. Simpler, and probably cheaper.

All methods of recharging will be designed around limitations. For example running the 120 VAC charger you know that >960 Watts must be supplied for it to work. That's one limit. Other limits may be reduced PV; if there's only room/money/practicality for a couple of GT panels so there's <600 Watts available then you have a case of "charge battery from PV, discharge to EV, repeat" wherein time is substituted for power. You'd get about an hour and a half EV charging from such a system, meaning the full charge would take about ten days.

Such panel size limits may be necessary if you're looking at installing them on the EV roof and getting what you can from them. In that case the direct DC option is more attractive, but you may not have enough PV to provide the Voltage for the whole bank so you'd end up doing it in segments and having to change wires around.

So much easier to haul a small gen and use it if you need it, not use it if you don't. You can do a partial charge or a full charge depending on what is needed and at the expense of probably less than one tank of fuel.

lolcashcow · October 2014

Re: Charging an EV /w an off-grid solar panel set up?

Cariboocoot wrote: »

The small Honda's could be rigged to provide the high charging level, but it would involve two of them plus a 4kVA transformer to get the Voltage. Might as well just buy one larger gen capable of 5kW to begin with. Simpler, and probably cheaper.

All methods of recharging will be designed around limitations. For example running the 120 VAC charger you know that >960 Watts must be supplied for it to work. That's one limit. Other limits may be reduced PV; if there's only room/money/practicality for a couple of GT panels so there's <600 Watts available then you have a case of "charge battery from PV, discharge to EV, repeat" wherein time is substituted for power. You'd get about an hour and a half EV charging from such a system, meaning the full charge would take about ten days.

Such panel size limits may be necessary if you're looking at installing them on the EV roof and getting what you can from them. In that case the direct DC option is more attractive, but you may not have enough PV to provide the Voltage for the whole bank so you'd end up doing it in segments and having to change wires around.

So much easier to haul a small gen and use it if you need it, not use it if you don't. You can do a partial charge or a full charge depending on what is needed and at the expense of probably less than one tank of fuel.

You are right cariboo. I've just been obsessed over the thought of never having to pay for electrictiy of gasoline. But like you said you still pay, just not the stations or grid plants. Nothing is free in life after all! You are right that getting the gasoline generator is the best option. Would save space and electricity as you would have to pull less with the EV.

The generator uses 1 gallon for an out put over time of 9 to 4 hours depending on the draw? So, with the EV needing about 1,000w per hour, and the Generator giving 2,000w per hour, that would be a total running time of about 4 hours wouldn't? If that is true, then you would be able to charge the EV for 4 hours total with 1 gallon of gasoline. I did a google search for "lv1 ev charging miles" and I saw a range of 3 to 5 miles per hour of Lv1 charging needing a total of about 17 hours for a full charge. So, about 4 miles per hour of charge at Lv1? More or less? 4*4=16 so that would be $3.50 (One Gallon of Gas) for 16 miles to drive in your car?

Unless I did something wrong? My math is not the best.... That does not seem very good to me.

gww1 · October 2014

Re: Charging an EV /w an off-grid solar panel set up?

Still, it might be better then $30 bucks for 17 mile if you bought solar/extra set of batteries, ect. I am just being a smart a-- (smile) cause I put no math to it.
gww

PNjunction · October 2014

Re: Charging an EV /w an off-grid solar panel set up?

lolcashcow wrote: »

You are right that getting the gasoline generator is the best option. Would save space and electricity as you would have to pull less with the EV.

Sounds like you talked yourself into a Chevy Volt! On-board gas generator kicks in to charge the batteries if your initial charge runs out on the road, and are nowhere near a charging station. From what I understand, it will do this underway if necessary.

Might be simpler overall than diy'ing a honda Eu2000 into a Nissan.

Cariboocoot · October 2014

Re: Charging an EV /w an off-grid solar panel set up?

lolcashcow wrote: »

You are right cariboo. I've just been obsessed over the thought of never having to pay for electrictiy of gasoline. But like you said you still pay, just not the stations or grid plants. Nothing is free in life after all! You are right that getting the gasoline generator is the best option. Would save space and electricity as you would have to pull less with the EV.

The generator uses 1 gallon for an out put over time of 9 to 4 hours depending on the draw? So, with the EV needing about 1,000w per hour, and the Generator giving 2,000w per hour, that would be a total running time of about 4 hours wouldn't? If that is true, then you would be able to charge the EV for 4 hours total with 1 gallon of gasoline. I did a google search for "lv1 ev charging miles" and I saw a range of 3 to 5 miles per hour of Lv1 charging needing a total of about 17 hours for a full charge. So, about 4 miles per hour of charge at Lv1? More or less? 4*4=16 so that would be $3.50 (One Gallon of Gas) for 16 miles to drive in your car?

Unless I did something wrong? My math is not the best.... That does not seem very good to me.

The numbers will vary depending on which gen you use and how much the charger actually draws; it may start out at 8 Amps AC and taper off as charge nears completion. I don't know. I do know the EU2000i can crank at full power (1600 Watts) for about 4 hours on a gallon. So the full charge should use less than 4 gallons of gas. The miles-per-hour-of-charge seems hopeless to me: 15 * 5 = maximum range of 75 miles? That would be useless where I live no matter how you charge it. You wouldn't be happy about the $5.50 a gallon gasoline either (hey, that's gone down!)

In contrast my 4Runner (what would I do without 4WD and 7.5" of ground clearance? Get stuck!) would use about 3 gallons to go the same (highway) distance. That's $16.50 for the gas-engined 4x4 or $22 for the EV.

Sometimes those rotten fossil fuels are better.

solar_dave · October 2014

Re: Charging an EV /w an off-grid solar panel set up?

PNjunction wrote: »

Sounds like you talked yourself into a Chevy Volt! On-board gas generator kicks in to charge the batteries if your initial charge runs out on the road, and are nowhere near a charging station. From what I understand, it will do this underway if necessary.

Might be simpler overall than diy'ing a honda Eu2000 into a Nissan.

Bingo! And the built in generator is more efficient than using a L1 charger and a generator. About 40 miles of driving per gallon. And yes the ICE kicks in automajicly and in fact has a "hold mode" that allows you to select when the ICE runs. Of course the most cost effective charge is with the grid even with higher electric rates (or with a grid tie solar setup). An 240V L2 charger consumes 3500 watts on a Chevy Volt providing a full charge in about 4 hours which is good for about 40-50 miles of range assuming low heat and A/C usage. With a L2 it is about 10 miles per hour of charge considering all the loses.

Cariboocoot · October 2014

Re: Charging an EV /w an off-grid solar panel set up?

Unless of course the Chevy Volt doesn't suit the vehicular needs.

offgridqld · October 2014

Re: Charging an EV /w an off-grid solar panel set up?

Thought I might have some real world experience to offer. I'm living off grid and own a OEM 100% battery powered electric car that we charge offgrid. We have 8200w of PV running through two midnite classic 150 mppt charge controllers. House Battery bank is 1330Ah at 48V feeding a 6000w continuous selectronic 240v AC inverter.

Our EV (Mitsubishi Imiev) has a 16kwh lithium battery and the stock supply EVSE has the on board charger running at 2200w (just under 10A at 240v) Typical our total consumption average is 130whr/km traveled or 208whr/mile. Measured at the wall plug so accounts for all running/charging losses. We live in the hinterland and the car has a good 100km+ range and takes around 13kwh to recharge after a 100km trip. Our offgrid system can cover the charging loads from empty to a full charge in one day + cover the homes loads and reach float (weather dependent though we have great weather where we live) That said our travel needs don't require a full charge each day as we travel less than 100km a day.

So yes living off grid and living with a EV works well (full independence) though it requires a reasonably big system to recover the consumption of the EV and house each day. Though a EV is just another AC load. Just like a swimming pool, extra refrigerator , Air conditioner. Once you know your typical daily consumption in KWH's you just size your system to meet your needs.

After skimming over the thread I see that some kind of mobile ...(bring your offgrid power with you) system is in question. In the past I would have rolled around laughing when this kind of idea was mentioned. Traditional aluminum frame and glass front solar panels weigh roughly 30lb- 35lb - 200w as you can see 700lb for 4000w! then you need the weight of a solid invert that can handle a good 2000 - 30000w load for several hrs (30lb) for even a high freq light weigh design. Then a buffer battery to keep the charging running if a cloud passes by small 48v lithium battery say 100 ah - 48v would be fine. (100lb)

As you can see your pushing 900lb of kit to charge your EV on the run!

There is hope though. thin flexible PV mono cells mounted into a flexible resin are available at roughly 2mm thick and just 6lb each for a 200w. Now we are only talking 120lb for 4000w of pv. a few mounted on the roof of a small van with a stack you could lay out on a open area while you camp. running your inverter and charger throughout the day (or even better direct DC charging. Yes In a slow moving (retired guy with all the time in the world ) camping for a day or two and then moving on another 60 - 80 miles and camping up for the day . i think it would work fine.

Economical viable....perhaps not unless you spent many years on the road to make it pay for its self. Fun ..... sure would be though you would spend a lot of time talking to people and being asked questions on how they could build a "sticking it to the man freedom machine"

I know I get a kick out of driving past the guys standing at fuel station in our EV powered from the sun .

Ps, I am actual building a small portable charging unit to extend the range of our EV by 30% for the odd long range trip we do. Using a small HF inverter and 48v/100ah lifepo4 cells. I can share the project if there is any interest.

Our EV charging offgrid

Kurt

Cariboocoot · October 2014

Re: Charging an EV /w an off-grid solar panel set up?

Welcome to the forum Kurt.

One question: do you have any numbers on how much this is costing you? Utility electric must be absurdly expensive where you are and gasoline even worse than Canada in order for this to make any sense at all.

Otherwise you're only fooling yourself and throwing away a lot of money.

offgridqld · October 2014

Re: Charging an EV /w an off-grid solar panel set up?

As for the economic value of my setup.

The home is offgrid and there is little choice as the the grid is some distance away from the property across harsh terrain. It would have cost several hundred thousand dollars to bring power in. Electricity is expensive in Australia. In my state it's roughly $0.30 kwh + a significant supply charge each day. So being off grid is economical viable particularly if your in a remote location without mains power like myself. We get good output value for every watt of PV we install as we have a lot of sunshine year round in our state, QLD Australia. Along with a reasonably strong /competitive PV industry so pricing on most components is resonable. Having a DIY attitude helps with the value return to.

As for the Ev. Our Imiev was purchased new in a run out sale (new old stock) for a similar price to a typical mid spec small Japaneses 4cyl petrol/diesel car. So no real price hike for owning a EV over a standard car. Local fuel prices are $1.60lt ($6.00 gal) The home had 4000w of pv and after purchasing the EV we installed a additional 4200w of pv on the garage to cover the EV's needs. Installed myself roughly $7,000 covering the PV, tilt racking, significant cable run, additional classic 150 charge controller , switch gear, fusing and so on. We were spending roughly $3000 PA on fuel driving our old other 4cyl car that we have now sold. So just over two years of driving the EV will pay back for the additional PV we installed to fuel it. We have had the car running for around 1 1/2 years.

It's not all about the $ though. Driving a car with zero emissions and no noise, one fixed gear and 100% torque from 0 rpm is something special. So that's worth a lot to me. Not having to pay for install and then dump oil through the sump every 6 months. then pay again to dispose of the nasty oil and chemicals and filters has some value to me to. I think the feeling of 100% Independence has a big value to me. Covering your home and transport needs without depending on others to fuel it. Shielding your self from inflation (big issue in this country).

I think if your savvy in how you go about seating it all up. If your local energy costs for conventional energy supply's are expensive and your geographical location is favorable for a form of renewable energy it works out well.

Kurt

Alaska Man · October 2014

Re: Charging an EV /w an off-grid solar panel set up?

Makes sense to me, wish it was an option for us. I've been looking at E.V s, but with little to no sun in the winter and -40°f being common for three months of the year we are stuck burning fossil fuels for transport.

There are plug ins at work we use them to keep our rigs from freezing up. Everybody has engine block, transmission and battery heaters installed. I could plug in during the day, (free charge up) but I'm afraid that the reduction of battery capacity in the coldest part of winter would mean major reduction in travel ranges. Then there is the need for heat inside the rig. How do E.Vs produce heat for winter travel?

offgridqld · October 2014

Re: Charging an EV /w an off-grid solar panel set up?

Different EV's do heating in different ways. The bast way is to just use the air conditioner and a reverse cycle valve for heating. (some issues with that in real cold areas though) The Ev we have just heats water and pumps it through a heater core. The seats are also heated. Heating will reduce the range. For me its not a issue as I don't use the heater at all (sub tropical location).

There are a few people driving them in very cold conditions. They preheat the cars while on charge and some in very harsh cold areas have fitted a small diesel heat exchanger unit that holds something like 1lt of diesel and just slowly burns it just for heat (aftermarket retrofitted kit)

Your own geographical location will determine how easy or hard it is to live with a off grid house and car.

Kurt

inetdog · October 2014

Re: Charging an EV /w an off-grid solar panel set up?

offgridqld wrote: »

... and some in very harsh cold areas have fitted a small diesel heat exchanger unit that holds something like 1lt of diesel and just slowly burns it just for heat (aftermarket retrofitted kit)

Similar, I would imagine to the aftermarket heaters built for the original air cooled (actually oil cooled) VW Bugs?

lolcashcow · October 2014

Re: Charging an EV /w an off-grid solar panel set up?

Hi guys,

Sorry for the late reply. I am still interested in the project! I have been really busy though. The thin and flexible pannels give some hope for sure! My guess is that these type of panels cost CONSIDERABLY more tthan regular panels? I think I have seen a few pictures online of cars LINED with really thin solar pannel 'waffles' on the roof? It seems like an interesting idea and more manageable than solid aluminum frame panels. The question is... what are these panels and how much do they cost? I have no idea how to start searching for them. Any information will be great!

For the project I do consider it being a type of camping project or even, if I am wild enough, a 'live in your van' type of project. There are a ton of people in L.A. that I see living inside their vans. Lots of astros too. So, anyway I mean the life style seems interesting. It does make me wonder how much it will take for it to pay off. How many years would you have to live in the EV for it to pay off?

I ran the idea of using a battery or two from the car to do the charging and then swaping them and got an answer:

"Morning,

The short answer is yes, of course they are and the number you need will depend entirely on the amount of power/voltage you require.

The long answer though is that these things aren't anywhere near as forgiving as conventional wet cells and will require a BMS/Hyrid inverter which incorporates lithium charging strategies - Whilst the CCCV is easily enough obtained I've yet to find any that incorporate balance charging, so for the moment at least, you will have to monitor cell balance manually or do some hacking.

Now, as an aside, lithium cells are not for the inexperienced. The chemistry and type used in the leaf modules is very stable and has high abuse tolerance, but you CANNOT think of them as your garden variety battery or things WILL end up in tears - this is something that you have to do fully properly or not at all - there is no middle ground. Given your apparent lack of knowledge in this regard I'd advise you to get VERY well acquainted with lithium battery characteristics and control strategies before you even think about going any farther."

http://visforvoltage.org/forum/13767-nissan-leaf-modules-li-conversion-questions?page=3#comment-73542

It would be nice if we could use the batteries from the car, but even if it is not possible that is not an idea killer. It would just save some cash. Though hif it is risky I can just settle for deep cycle AGM batteries.

Charging an EV /w an off-grid solar panel set up?

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