Need help with batteries

inthejungle

I wanted to see what everyone's thoughts were. My wife and I just move to W. Africa. I have done some investigation into batteries locally. If I want to go with deep cycle batteries the options are quite limited. I have found

 

Naracla 12v 100 amp hr batteries for 282usd a piece so for the 5 batteries 1,400. This is a brand another friend has used for a few months and seems to think that they are going to work out well. From there the price goes up, I can even get CAT batteries for about 500 a piece.

 

The other option is AC Delco truck batteries. With these I can find 120ah battery for 176 and if I got 4 of these I would pay 705. These are not deep cycle or solar in any way. With this option my battery bank would only be 480ah.

 

What do you think? It seems to me that all batteries in this heat are not going to last that long, why spend money on the more expensive kind.

Thoughts?

westbranch

I can't find that name at all...  do you have a link to the specs?

mike95490

Truck batteries are generally starting batteries, not deep cycle batteries.
 Any golf courses at resorts ?  They use 6v 200ah batteries, worth using parallel strings if you can't get the optimum batteries.

inthejungle

Sorry internet has not been working, mike95490 can't say I have seem any golf courses in the Sahara.
Westbranch- I can't find anything out myself about that brand.

Any thoughts on what to do when there are not really any good options? Power is going off about 2-3 hours a day right now and will only get worse. Should I just look at getting some large truck batteries and plan on replacing them more often?

Thoughts

BB.

If your outage is only, on average 2-3 hours per day--If you can just decide which "important" items you wish to keep powered (for example, maybe radio, LED lighting, TV, small fan) for 3 hours per day and "shallow discharge" the battery bank--At least for automotive (or truck) batteries, it would help the bank last much longer. As an example:

• 30 Watts Radio + 30 Watt LED lighting + 30 Watts TV + 50 Watt fan = 140 Watts total
• 140 Watts * 3 Hours = 420 Watt*Hours per outage
• 420 Watt*Hours * 1/0.85 AC inverter eff * 1/12 volt battery bank * 1/0.15 maximum depth of discharge = 275 AH @ 12 volt battery bank

That is a fairly reasonable size battery bank (~4x 12 volt @ 80 AH "pickup size" truck/large car batteries).

I do not recommend putting your refrigerator on the battery bank--Refrigerators can "ride through" short power outages just fine--But if you do need to put "warm food" from the store into the fridge (shopping trip) into the fridge during power outages--Then I would look at putting the fridge on the backup power system--But that would make the battery bank ~2x larger, and you would probably need a 1,200 to 1,500 watt AC inverter minimum. An alternative would be to freeze a couple of gallons of water (when you have AC mains power) and put the frozen plastic water bottles in an insulated cooler + your food from the store to chill during outages--Then once the power has been restored, put the food in the fridge and the plastic jugs back in the freezer. (you are using the ice to "store power" instead of a larger battery bank--Can save a bunch of money).

If you can find larger (reasonably priced) truck batteries (say for large diesel trucks)--Those would probably be better. I do not really like to put 4x or more batteries in parallel, if I can avoid it.

-Bill

softdown

A 120 Ah truck battery ought to weigh about 80 pounds I think. Ah ratings can be based on different things. Bigger is always better with batteries. The fact that the truck batteries carry an Ah rating is generally positive. Do they also carry a CCA (cold cranking amp) rating?

Generally...you want a higher Ah rating and a lower CCA rating. Study the "fine print"....look for the words "deep cycle".

Anyway...you will be hard pressed to beat ordinary, cheap 6 volt golf cart batteries for delivering the best bang for the buck...by far.

Keep your batteries as cool as possible. This is very important.

Photowhit

You may find that the truck batteries aren't too bad. The 'car starting' batteries in Europe are better for cycling than the U.S. Lead Calcium. Lead selenium is used in Europe, in general, and has better cycling characteristics. I would recommend staying away from Lead calcium for cycling use, even shallow cycling.

If you can, ask for the type of chemistry/metal content of the battery. Good luck!

inthejungle

THANK YOU FOR EVERYONE'S THOUGHTS, I thought I had a few months until the hot season to sort this out, but this past week we have average a 2-3 hour cut each day and last night we shut off at 8 then back on at 12 for 45 minutes and off until 6 on for 15 minutes and then back on an hour later when I left. I guess that makes a 9-10 hour cut. The fridge was still cold and the Ice had not even started to melt. I have been filling the fridge up with 1.5 liter bottles of water in any empty spaces and making sure that the freezer is full as well with food. We have a 10 month old and 100 in the room while trying to sleep was a killer!

I wanted to attache photos of the batteries but the internet is no working well today, thoughts or other ides? The Model is an AC Delco NX 120-7LMF

I heard yesterday that someone maybe shipping out a container, if anyone had a good idea of batteries that I might ship that would handle the Sahara heat that would helpful. I am trying to compare costs at the moment.

At the moment I have with me a 1600w Victron inverter with a transfer switch built in. I also brought with me some thin-lite LED lights. I had hoped to find good local batteries. Any other suggestions?

Thanks

softdown

Not aware of batteries being built for Sahara like heat. How deep do you have to dig before it cools down? Hot batteries do not last in the USA.

Marc Kurth

inthejungle said:

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I wanted to attache photos of the batteries but the internet is no working well today, thoughts or other ides? The Model is an AC Delco NX 120-7LMF

Thanks

If that is about all that you can reasonably get, this is how I would approach it.

That battery seems to be listed as part of their "value line" as opposed to "heavy duty"
This is a fairly small battery - roughly equivalent to a BCI Group 24 battery.

The Delco ratings at 25C seem to be:
75 ah at a 20 hr rate
130 minutes run time with a 25 amp load
20kg/44 lbs.

Hard to find more info, but based on the published CCA and the very light battery weight, I suspect that you will get around 75-100 cycles to a 50% depth of discharge. Without good published data, this is strictly an estimate!  It could be half of that, but not likely double :-)

BUT as some very smart people have already said, you just might be able to make them work IF you have enough of them to keep the discharge cycles very shallow. The easy number to work with above, is the 130 minutes at 25 amps.

For example, if you have a 25 amp load using these batteries:
One battery would be drained to zero remaining capacity in 130 minutes.
Six batteries would be drained to zero remaining capacity in 780 minutes.

Turning that around, six of these batteries running with a 25 amp load would still be at 75% charge after 195 minutes (3.25 hours)

Remember that each battery is rated for 12v x 75 ah = 900 watt-hours of power IF you drain the battery to "0%" - but you should be shooting for something between 15% and 25% depth of discharge in order to get a few hundred cycles from these batteries.

There are times to buy fewer batteries and replace them more often. If your batteries will be living in very high ambient conditions, this might be one of those times.

Marc

Dave Angelini

Where is a large city near you and what is the name ?  Is there a place there that can reliably recieve an international shipment?  What is the duty or import tax?  Do you have a vehicle that can carry batteries?  100 degrees really is not fun, good luck!

softdown

44 pound batteries in a solar application is asking for heart ache. Try really hard to find 6 volt golf cart batteries. They probably weigh about 80 pounds each. They work well for solar and are the cheapest, good solar battery by far.

Car and truck batteries can be made to work in a pinch...if they are quite large and a lot are used. Mine weigh 125 pounds each. They were not a good choice but not a real bad choice either. They were a recommended choice.

Sorry I don't know much about the Saharan environment. May not be much golfing going on?

inthejungle

Well I wanted to ask for some thoughts- I went today and looked around again. On the advice of a friend I went to a solar store. They sell Chineese products, the brand Name is Narada there website is naradabattery.com, on the side of the battery this is the only specs I can find Narada MPG Series Polymer Gel Battery Model: MPG12V100F Capacity 12v100ah, c10 to 1. 80vpc@25C Float Voltage: 2.25Vpc@25c These boys are a bit more heft at 38.5Kg according to the box. Can someone help me think through the number of this? I have a number of 330Watts for my fridge. Thanks

inthejungle

Here is the spec sheet I pulled from there website here
http://en.naradapower.com/index.php/products/info/27?ctype=

The only initial thought I have it I have a Victron Multi Plus 1600w Inverter, these are AGM, I didn't have a chance to get a temp sensor?

softdown

Decent sized battery this time.....that is good.  I don't think we have many posters that are familiar with Chinese solar batteries. Big improvement over a 44 pound car battery.

Marc Kurth

The new battery option is far better than the original, but they are actually gel batteries, not AGM's. That battery is specifically deigned for UPS/Standby type service with occasional cycles upon power outage. But it is capable of daily cycling, unlike the car battery option.

But that means that you need to treat it more gently than you would with something like a standard golf cart battery. I can explain more, but essentially you need to charge those batteries at the appropriate rate and you don't want to cycle them too deeply on a daily basis. The more critical of the two is the charge rate!

1) How many of these will your budget support?
2) What do you see as your hourly load in watts?
3) How many hours do you want to hold that load?

I do understand that this uncharted territory in some ways, but start throwing out some numbers and the more experienced folks hare can help guide your decision process.

Marc

westbranch

In the Jungle, could you please ad a signature line for us to see the loads etc that you have to feed power to, load duration, etc, as well as any equipment you have already.

thanks, saves having to reread previous posts to keep on topic

inthejungle

Marc and Westbranch- thank you WB you should see my signature now I have look at some LG Spec Sheets for inverter compressor Fridges mine is a compressor Model LG FMA 102NAMA, I believe that it is around 300w, my thoughts are to leave it off after a power failure for 1-2 hours, as I have seen very little temp change internally with short power cuts. Then turn it on to battery back up, I would like to back it up for 8-10 hours. I believe the numbers look like this 300w/12 V or 25 x 8 hours of backup 200ah if I wanted 50% discharge then I need 400AH bank, with these batteries according to Marc I don't want a very deep discharge so maybe I should shoot for 500ah How do those numbers look?

inthejungle

Update on my DC power sources, my thin lite LED's are .4 amp draw maybe used for an 30 minutes to an hour if it is night time
O2 Cool fans are .5 amp draw there would be 4 so .5x4 2amps x7 hours 14ah

For what it is worth

Dave Angelini

The reason I asked about your exact location (a big city nearby) was I have shipped to your continent and I was going to see how much it would cost gratis.  If you get something decent nearby it is the way to go as I doubt there would be much of a warranty thru my supplier.

inthejungle

Maybe this can help, here the sticker on the inside of the fridge for power specs. What should I use the Watts or rated current?

Dave Angelini

Well, it says rated current right?  The part that many do not understand, not just you, is that the power will often be alot less to none at all during normal operation. If you open the door excessively in a hot climate or the unit goes into defrost mode because of humidity
you may use more. The unit cycles and the variable speed compressor uses different amounts of the rated 1.5A @ 220vac if this is an inverter unit.

BB.

I could not find much in the way of EEI (European) energy ratings other than one vendor that said this was a A++ rated device (very good, A+++ is now best).

An Algerian (made?) A rated brand uses 398 kWH per year (if I understand the French correctly).

The 1.5 Amp rating is (probably) almost useless for our needs. I would guess it is the average starting current (for a few seconds, warm/hot start). The running wattage is probably around ~120 watts or so. The starting wattage/amperage is unknown (did not find anything that said this is a linear compressor or "inverter" refrigerator which tends to imply that it would have low to zero starting surge current).

The refrigerator/freezer can use as low as 350 kWH per year, or if a US model, could use as much as 400 to 450+ kWH per year. If your starting assumption is ~1,000 WH per day (365 days per year)--You are (very big guess on my part) would be in the ball park. Hot weather region--Assume ~1,200 WH per day (summer) would probably be safer.

If you are using a 1,200 Watt (or larger) AC inverter and appropriate battery bank (call it >480 AH @ 12 volt,  >240 AH @ 24 volt, or >120 AH @ 48 volt battery bank), it should start the refrigerator.

Assume worst case loads (refrigerator running continuously--fresh food/freezer load, hot day), and your other loads (less than 30 watts DC?):

• 120 Watts * 10 hours * 1/0.85 inverter eff * 1/12 volts = 118 AH
• 30 Watts * 10 hours DC / 12 volts = 25 AH
• (118 AH + 25 AH) * 1/0.25 maximum discharge (truck/automotive battery bank) = 497 AH @ 12 volt rated battery bank (worst case assumptions).

If you assume the fridge runs at an estimated 1.2 kWH per day (average load, not worst case):

• 1,200 WH * 1/0.85 inverter eff * 10 hours per day * 1/24 hours per day rating * 1/12 volt battery bank = 49 AH @ 12 volts per 10 hours
• (49 AH fridge + 25 AH fans+lights) * 1/0.25 maximum battery discharge = 296 AH @ 12 volts minimum (based on average/guesstimate loads)

The inverter's 70 amp charging current will (reasonably nicely) support >10% rate of charge for a 296 AH to 497 AH @ 12 volt battery bank.

The unknown here is the starting surge--A 296 AH battery bank may or may not start your refrigerator reliably. A >480 AH @ 12 volts will probably start any "reasonable" residential refrigerator just fine.

Your inverter is rated for 1,600 Watt continuous, so the minimum flooded cell deep cycle battery bank suggested would be:

• 1.6 kWatt rating * 400 AH per 1.0 kW (at 12 volt battery bank) = 640 AH @ 12 volt battery bank for "full rated" inverter output/surge rated output.

For AGMs batteries, they (in general) support much higher surge current rating than flooded cell--So you could start with a 296 AH @ 12 volt battery bank and see how it runs for you (obviously, you need nice heavy/short copper cables from the battery bank to the DC input of the inverter). And the usual suggestion on how best to wire the battery bank:

http://smartgauge.co.uk/batt_con.html

The 296 AH @ 12 volt battery bank is, probably, pretty conservatively rated for your usage (25% discharge for 10 hour outage, normal fridge operation). And if the battery bank is insufficient, you could always add 1-2 more parallel batteries (12 volt @ 100 AH AGMs?) a few weeks/months down the road.

-Bill

jonr

...a 9-10 hour cut. The fridge was still cold and the Ice had not even started to melt. I have been filling the fridge up with 1.5 liter bottles of water in any empty spaces...

Water helps a  lot and is cheaper than batteries.  In the freezer, you should use a mix of non-toxic anti-freeze (25-30%) and water (to lower the phase change temperature).

Dave Angelini

To me this looks like an 17.4 cubic foot refrigerator Bill. What are you using? I saw R600 refrigerant which sort of implies a linear compressor.

BB.

Just searched the model number. Mostly genetic LG information.

-Bill

inthejungle

This is a linear compressor, on the front of the machine it makes a big deal of saying inverter linear compressor- Well I got some good news today. I found another person working with our organization in the region. They are running a clinic completely off solar. He is coming my way to help install a system. He can get Rolls batteries, s550 450ah!
I am thinking of getting a set of these that would back up the fridge quite nicely!

He has some panels as well, I am just running a bit thin on money, what do you think he has Up Solar 230W – Poly solar panel's. If I got some of these I won't have much left for a charge controller. What kind of charge controller could I use?

Dave Angelini

What can you get for a charge controller? The best choice would be something from victron that might communicate with your inverter. The Batteries sound like just what you need. Good Luck

westbranch

just looked at the specs on those panels. http://www.solardesigntool.com/components/module-panel-solar/Upsolar/610/UP-M230P-60/specification-data-sheet.html
They are a Grid Tie panel with a  29.7V Vmp so will not be able to charge a 24 volt battery if you arrange them in parallel, you would need 2 in series for 24v, but parallel is OK for 12v with an MPPT charger.
A PWM charger will not be able to use the full wattage the panel is capable of.
Tell us how many panels you buy, that will help define some limitations and achievables, etc....

inthejungle

Thank you for everyone's help, I am thinking that the panels outpuld 230wx3=690w x 5 hours of sun each day is roughly 3,400
If we estimate that we need 1.2kw a day that should do nicely,

In regards to charge controllers, I am thinking about using
BLUE SOLAR MPPT or this BLUE SOLAR MPPT

Thoughts?

softdown

Never heard of them. What makes you interested?