Portable Solar Power

RWB
RWB Solar Expert Posts: 168 ✭✭✭✭✭
in Solar Product Reviews & Opinions #1
Hey guys I've been around this forum for some time just have popped in here and there over time. I'm not trying to advertise with this post I'm just wanting your guys feedback on this system me and my partner just created.

This is a 100 Amp Hour Lithium Iron Phosphate Battery that contains no toxic ingredients. It weighs half the weight of a 100 Amp Hour Lead Acid Battery. The battery will give you 5000 Cycles with an average 70% DOD, and 3000 Cycles with a 80% regular discharge. Which is much better than a Lead Acid Battery at those DOD rates. After the those charge cycles have been met the batter will slowly drop its amp hour capacity rating over time.

You can drain LFP Batteries at 1C rates and still get the full Amp Hour Rating out of them from my testing.

The complete system weighs 60 pounds.

The Solar Charge Controller is a Sunsaver MPPT so you can use up to 200w of solar panel to recharge the battery.

There are 2 Cigarette Lighter Sockets, each protected by a 15A Bussman Breaker.

There are 2 Remote Battery Terminals that allow you to discharge or charge the battery or expand another battery to increase storage capacity. You could hook more solar charging power, or keep the case closed and use an external inverter if needed.

The battery monitor displays time to go until recharge is needed, SOC Display, Amps In/Out, AH Total, Voltage, and has a 30 or so long data logging feature.

A 2 wire generator remote starting output is also an option with custom On and Off points based on SOC or Amp Hours.

Anyways we have been working on getting this built for a few now and had many delays due to other people delaying us but here is what we consider a killer 100Ah Portable Solar Power System.

What do you guys think about this?
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Comments

  • RWB
    RWB Solar Expert Posts: 168 ✭✭✭✭✭
    #2
    Re: Portable Solar Power

    ...More Pictures To See
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  • RWB
    RWB Solar Expert Posts: 168 ✭✭✭✭✭
    #3
    Re: Portable Solar Power

    More Pictures, more pictures
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  • RWB
    RWB Solar Expert Posts: 168 ✭✭✭✭✭
    #4
    Re: Portable Solar Power

    Last of the Pictures...........................
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #5
    Re: Portable Solar Power

    Looks nice...

    So you can charge with a 12 volt lead acid type battery charger (no modifications needed?).

    What kind of surge/maximum current can you draw from the 100 AH battery pack?

    Some very impressive life cycle specifications.

    Any drawbacks/issues/differences when using this vs Lead Acid? Long life and 1/2 the weight sure is nice.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • RWB
    RWB Solar Expert Posts: 168 ✭✭✭✭✭
    #6
    Re: Portable Solar Power
    BB. wrote: »
    Looks nice...

    So you can charge with a 12 volt lead acid type battery charger (no modifications needed?).

    What kind of surge/maximum current can you draw from the 100 AH battery pack?

    Some very impressive life cycle specifications.

    Any drawbacks/issues/differences when using this vs Lead Acid? Long life and 1/2 the weight sure is nice.

    -Bill

    Hey BB

    Yes you can charge with a standard Lead Acid Type Battery Charger with no problems but the system comes with a 20A LFP Specific Battery Charger with a LED Readout. The LFP Charger has 4 different charging processes and charges on a pulse type program that is best for LFP Batteries. It finishes off charging once the battery has reached 15V. The Solar Charge Controller charges to 14.6V.

    A regular Lead Acid battery will usually not bring the battery voltage up to 14.6v so it will not reset the Battery Monitor to a full 100% but it will charge the battery up to 90-95% without problems.

    The system is protected by a main 120A Bussman Breaker, so 12v up to 120A DC via the Remote Battery Terminals until the breaker trips.

    The inverter is a 1250W Continuous AC Rated Inverter with a 3500W Surge Capacity, its a Modified Sine Wave inverter. If you need Pure sine wave then just attach on to the other 12v DC ports.

    Yes Very Impressive Life Cycles in Deed :) No reason to even look at a Lead Acid Battery Again no matter how you look at it unless your on a super tight budget. Not to mention a 50% weight Reduction, and up to 66% less weight on the 200Ah Batteries.

    No trade offs besides a price that is double the cost of lead acid, but when you factor in it will last you so much longer and you can drain them further without damage like 70% or 80% vs 30-50% on a Lead Acid Battery then you can actually end up needing to buy less batteries if you go with LFP vs Lead Acid. For now its hands down better than Lead Acid.
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  • RWB
    RWB Solar Expert Posts: 168 ✭✭✭✭✭
    #7
    Re: Portable Solar Power

    What is the smallest Honda Generator that I could get to Start from a 2 wire Output to charge this system automatically when the battery hit a 20% State of Charge and Turn off when it hit a 75 or 100% State of Charge?
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  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #8
    Re: Portable Solar Power

    i don't know about the generator, but that battery does sound interesting. what kind of dimensions are we talking for it? is it able to be in odd positions? you say you and a partner invented it, if so my hat's off to you.:D
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  • russ
    russ Solar Expert Posts: 593 ✭✭
    #9
    Re: Portable Solar Power

    A different party keeps trying to place a link for something similar on another site where İ am a moderator - 695 USD for their toy - this looks a bit better though.
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  • RWB
    RWB Solar Expert Posts: 168 ✭✭✭✭✭
    #10
    Re: Portable Solar Power
    niel wrote: »
    i don't know about the generator, but that battery does sound interesting. what kind of dimensions are we talking for it? is it able to be in odd positions? you say you and a partner invented it, if so my hat's off to you.:D

    Thanks Niel, yes we invented it, and another smaller 40Ah LFP System that is 24 Pounds that lives in a Sling Pack.

    We are going to pair it up with some 21% Efficient Foldable Solar Panels in the very near future. See the attached picture.

    Yes the system can be in any position or if you are talking specifically about the batteries the same goes, any position is fine.

    The dimensions of the system is External Size:

    * Length: 13.78in
    * Width: 21.46in
    * Depth: 9.05in
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #11
    Re: Portable Solar Power

    The smallest Honda genset with electric start is (I think) the eu3000i... A nice genset, but no setup for automatic starting at all. A lot of work and a controller would be needed for conversion.

    We looked around a year or so ago here--and did not find anything for the Honda that seemed to be a good fit (controller/conversion wise). There was one conversion but used a wireless keyfob for eu3000i control.

    Automatic Starting Thread

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • RWB
    RWB Solar Expert Posts: 168 ✭✭✭✭✭
    #12
    Re: Portable Solar Power

    Here are some pics of the 21% Efficient Foldable Solar panels.

    They are using SunPower Cells.

    There is a 110W Panel and a 220W Panel.

    This time of year I am seeing 85-90watts out of the 110w panel in Indiana. I have seen this panel put out 100 Watts this time of year also, can't wait till summer comes around to see how it performs then.
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  • RWB
    RWB Solar Expert Posts: 168 ✭✭✭✭✭
    #13
    Re: Portable Solar Power
    BB. wrote: »
    The smallest Honda genset with electric start is (I think) the eu3000i... A nice genset, but no setup for automatic starting at all. A lot of work and a controller would be needed for conversion.

    We looked around a year or so ago here--and did not find anything for the Honda that seemed to be a good fit (controller/conversion wise). There was one conversion but used a wireless keyfob for eu3000i control.

    Automatic Starting Thread

    -Bill

    Thanks Bill, I'm looking to see what my options are in the small genset range with Auto Start Function. I did come across the remote start options. I used to install remote car starts so I know how they work except these generators are not as nice as car engines.

    Sure would be nice if we could auto start a Honda 2000i :)
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  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #14
    Re: Portable Solar Power

    rwb,
    you certainly put allot of work into that. i was curious of the battery dimensions especially as how they compare to fla and agm. i'll bet the cells were something to connect and make for portable operations too. give more details if you would as this is 1st class diy. is that you in the pic? what motivated you to do all of this out of curiosity?
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  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #15
    Re: Portable Solar Power

    very nice and it is interesting both for the battery and the portable pvs. i guess you corrected my misthinking this to be a diy from a couple of guys being it is a business. i'd like to hear more of them as to their longevity, durability, and anything else in general that is of note.
    being windsun does not sell what you have please post a link for me to see more if you have one.
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  • nigtomdaw
    nigtomdaw Solar Expert Posts: 705 ✭✭
    #16
    Re: Portable Solar Power

    Niel and others might find this site interesting

    http://www.electric-motor-cars.com/Navagation%20pages/battery_packs.htm#top of page

    These guys deal with type of battery and have a free spread sheet programme to give you a costing on these batteries used in Electric Car Conversions. I entered in a bank size of 24 volt 800 amp hours and got a costing of $7200.
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  • AntronX
    AntronX Solar Expert Posts: 462 ✭✭
    #17
    Re: Portable Solar Power
    RWB wrote: »
    Here are some pics of the 21% Efficient Foldable Solar panels.

    They are using SunPower Cells.

    Where do you get those? I would like to build myself such kit.

    Some thoughts on the battery:
    LiFePO4 batteries you can buy today for $1.1 per Ah per cell. So, 100Ah 3.2V cell costs $110. They are made in China by ThunderSky, imported to the US by company named EVcomponents. These batteries like partial charges, especially to be kept at average SOC of 50% and cool temperature for longest calendar life. So, partially charging them is good. They have very high charge/discharge efficiency of 97 - 99%. And high cycle life, 3000 of 70% DoD cycles, 2000 of 80% DoD cycles before dropping to 80% of original capacity. They are great for off-grid and grid power shifting (buying off-peak, selling on-peak). Down side is, they cannot be simply charged in series like LA batteries, but charged with either smart charger that monitors each cell voltage and stops charging when either cell gets to cut-off voltage, or with voltage clamps on each cell and regular LA charger. When discharging, each cell must be voltage monitored as well to interrupt discharging process. And estimating state of charge is trickier because voltage discharge curve is not linear, but almost flat, dropping like a cliff at the end of cycle. That's why monitoring each cell is required.
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  • GreenerPower
    GreenerPower Solar Expert Posts: 264 ✭✭✭✭✭✭
    #18
    Re: Portable Solar Power

    An interesting report on LiFePO4, well maybe a little bit biased since they sell those. Here is the explanation why individual cell needs to be managed properly.
    http://www.hotjuiceelectric.com/beq1lifepo4.html wrote:
    A characteristic of Lithium Iron Phosphate cells is their abrupt drop in charging current when they reach 100% State Of Charge (SOC). See graph below. This poses a problem when the cells are charged in a series string with a single charger. Even with a perfectly balanced pack, the cells do not all reach 100% SOC at exactly the same time. The first cell to reach 100% SOC will drop its current (see graph below). Since the cells are wired in series, this will also drop the current through all the other cells. Since the other cells have not reached 100% SOC their impedance will be lower than the 100% SOC cell. This will cause the voltage across the 100% SOC cell to exceed damaging levels in addition to preventing the remaining cells from completing their charge.
    The "battery management" system for high AH cells are fairly expensive.
    GP
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  • GreenerPower
    GreenerPower Solar Expert Posts: 264 ✭✭✭✭✭✭
    #19
    Re: Portable Solar Power
    en.wikipedia.org/wiki/Lithium_iron_phosphate_battery wrote:
    Cell voltage = min. discharge voltage = 2.8 V. Working voltage = 3.0V–3.3 V. Max. charge voltage = 3.6 V.
    www.lifebatt.com/asksparky.html wrote:
    LiFePO4 charging systems must never exceed thresholds where voltage and current applied to a Lithium-Iron-Phosphate cell could overcharge it.
    ...
    In contrast, overcharging LiFePO4 battery cells just one time will disable them by damaging the ion-transference capability of their electrolyte chemistry.

    from http://www.thunder-sky.com/pdf/2007030222.pdf (attached below)

    Even with a 12V pack, after a few hundred cycles, my guess they could stray apart. When one cell reaches full first, it could easily get more than 3.6V voltage across it.

    RWB, do you have any test data from yourself or from the vendor(s). I couldn't find any on the net. I've been looking at these to use for myself for sometime.

    GP
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  • GreenerPower
    GreenerPower Solar Expert Posts: 264 ✭✭✭✭✭✭
    #20
    Re: Portable Solar Power

    Thanks, the excerpt captured in my earlier post was from a link of a battery spec from that site. I was looking for test data if a 12V pack is still OK without a BMS after 1000s of cycles. Then I could use 12V battery equalizers like PowerCheq to balance every 12V stack, if I were to build my 48V system from single LifePO4 cells (I'm thinking 200AH cells). I guess no way without a real BMS ?
    GP
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  • AntronX
    AntronX Solar Expert Posts: 462 ✭✭
    #21
    Re: Portable Solar Power
    GreenerPower wrote: »
    I was looking for test data if a 12V pack is still OK without a BMS after 1000s of cycles.

    Don't charge without monitoring each cell's voltage. You can charge "by hand" few times, but you have to watch each cell with volt meter. If you let any cell get above maximum safe voltage, you will damage it. Here is cheaper balancing solution for those batteries: http://www.cleanpowerauto.com/MiniBMS.html You also would have to set up load disconnect switch to turn off your loads in case any cell get's to it's minimum voltage. There are no commercial products designed for Lithium batteries to be used in off-grid solar, so you have to figure out your own ways to properly integrate these batteries into your system.
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  • GreenerPower
    GreenerPower Solar Expert Posts: 264 ✭✭✭✭✭✭
    #22
    Re: Portable Solar Power

    Thanks for all the links. Probably I'll test drive a small AH cells set first before spending $$$ on the big ones.
    GP
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #23
    Re: Portable Solar Power

    Please note--I have merged serveral other LFP threads into one technical discussion thread (hope it works out):

    Lithium Iron Phosphate Batteries; LFP; LiFePO4 discussions

    Please feel free to discuss the Portable Solar Power product in this thread.

    -Bill B. Moderator
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • Opti
    Opti Registered Users Posts: 10 ✭✭
    #24
    Re: Portable Solar Power
    RWB wrote: »
    Hey BB

    Yes you can charge with a standard Lead Acid Type Battery Charger with no problems but the system comes with a 20A LFP Specific Battery Charger with a LED Readout. The LFP Charger has 4 different charging processes and charges on a pulse type program that is best for LFP Batteries. It finishes off charging once the battery has reached 15V. The Solar Charge Controller charges to 14.6V. .
    RWB, you mention in your first post using a Sunsaver MPPT charge controller but in the above comment you reference a LFP specific battery charger.

    Are these the same system or two different versions, or am I just seeing the process you are taking putting it together testing different components?

    What type of LFP specific charge controller works well with solar panels?
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