# Batteries!



## Matt Eklund (Nov 10, 2017)

Would like to get some opinions on batteries for our off grid solar system.

If your not tied to the grid what’s the best batterie to use? Or what’s been working best for you so far?


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## ET1 SS (Oct 22, 2005)

I am on different solar power forums, after wading through a lot of debate on this topic. I found one factoid that rang true among all of the experienced system operators. After a decade, your first battery-bank will die.

So I went to each of my off-grid neighbors, and I asked them. They responses were all in agreement. As you learn to adjust to the lifestyle of living off-grid, you will kill your first battery-bank at around the one decade mark. 

If you spend $100 per battery or if you spend $1,000 per battery, they all last the same length of time.

Installers wanted to sell me $800 batteries. But I went to our local Tractor Supply store and I bought 24 $90 Marine grade deep cycle batteries.

Two years later, I think I made the right choice.


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## Offgrid48 (Jul 28, 2016)

I went with a 48v system and did extensive research and comparisons of different battery types, configurations and price. I ended up buying a SINGLE 1600ah 48v forklift battery. These batteries are designed to be discharged and recharged and will last 20 years with proper maintenance. Downside is this battery weighs about 4000lbs. So getting it in place was a challenge but for the cost, this was the best bang for the buck. I spent about $5k for the battery almost 4 years ago and it's still going strong. Also, i don't have to worry about batteries getting out of sync when replacing individual batteries. Forklift batteries are available in 12v, 24v, 36 v, and 48v.


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## Steve_S (Feb 25, 2015)

ETS1 is correct, the first bank will be killed if it's Lead Acid, and 7-10 years average for the first bank... although I know one guy who killed 8 Rolls Surettes in 18 month, kept discharging them to 0 ! which is guaranteed to kill'em. BUT Lithium Ion Batteries are no problem for 100% discharge and they do recharge fairly fast to 80% and then slow charge the balance. LiIon is quite a bit more expensive but you get 90% of the battery (always good to leave 10%) to use, no offgasses (hydrogen), safe & reliable, as for lifespan, very long as they are static.

I use Rolls Surrette S-550 Flooded Lead Acid batteries, great batteries but need care and attention. Bought them when LiIon was insane 4 yrs ago! IF I was to buy today, LiIon would be the choice because prices are much better now. Do not use car batteries or even RV/Marine batteries they are just not designed for deep discharge or high amp delivery. Lead Acid Deep Cycle Batteries from Trojan, Rolls Surrette, and similar are designed for such hard uses. 


There are many companies and a few different types of LiIon battery packs. Some folks even use recycled Electric Car Batteries (some companies are recycling LiIon Car batteries into household storage banks - Renault for example in Europe and others). LiIon batteries have also come down significantly and will continue to do so, as production is ramping up worldwide for EV's, Grid & Home storage and more. Temperatures are also really no problem with LiIon either. NOTE there is still a great deal of misinformation on LiIon out there as well as some confused bad info, so be aware of that... LiIon is more expensive than other types but also no fuss, more capacity, tougher and double the life cycle +. 

You can go $$$ with a tesla Powerwall or any number of alternatives too, here's a couple of links for some well known common brands. 

http://simpliphipower.com/ 
https://battlebornbatteries.com/
http://www.relionbattery.com/


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## Fire-Man (Apr 30, 2005)

Offgrid48 said:


> Also, i don't have to worry about batteries getting out of sync when replacing individual batteries.


 You do not have to worry about someone picking it up and walking off either.


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## Al Yaz (Jun 13, 2017)

First set of batteries and they are going on 12 years. Davidson 2v - 24v system. Still have good life in them.


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## damoc (Jul 14, 2007)

As others have said lead acid batteries are the weak link in our off grid systems being expensive,heavy,difficult to repair recycle or rebuild and relatively short lives.In this video I try to build a solid lead plate battery which the theory is should last decades even with abuse however the size versus storage capacity was disapointing to me I was hoping and expecting better storage.Hope this is of use any ideas or advice would be appreciated Im thinking of building a much bigger one.


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