Best type of battery?

[Sonshine]

Hi

I am just starting to put together my first solar system and am wondering what the best type of battery is.  I get the deep cycle part but I am wandering about Lead acid or Gel batteries etc.

Advice appreciated!

Trevor

[dbcollen]

Flooded lead acid is the most forgiving, and usually the cheapest type. Trojan T-105 or wal-mart or sams club golf cart batteries are good for beginner systems. They take a lot of abuse, have moderate capacity, and are relatively inexpensive. I would not even consider Gel or AGM batteries, as they are really not suited for heavy duty use and one serious overcharge and they are useless.

Just my $.02

Dustin

[RogerAS]

Agreed,

I have used the Sam's Club 6V golf cart batteries for several years. Had I spent my first dollars on some Rolls or equal I surely would have ruined them too, it just would have taken a little longer, maybe. I feel these are good batteries for the money, and until one learns how to give batteries the TLC they demand the value curve flattens quickly between these and more expensive batteries.

If and when I get my system like I really want it I will have some nice expensive batteries that will last 10 years, and I can quit messin' with the system and worrying 'bout batteries and their state of charge, temperature and specific gravity and post connections and fusing and and and...

I'll have enough solar and wind to store the power for longer and more of it. Even then I imagine I'll go with some really thick plate flooded type, like the "jar" 2V cells or fork lift batteries, and have a mid range 48V storage voltage.

Ah to dream.

Until then I'll probably buy one more set of the 6V like I already have, maybe expanding the amp hr capacity by 20-30%, by the start of summer. I'll have 4 years on the current set, and pretty hard off grid use and abuse. Adding to the capacity of the bank and more solar and wind input will help (which I plan to implement before fall). In the end the batteries are always the weak point in the system. Flooded lead acid batteries, while tough, can be killed quickly too, and I've been there and done that, but until a more economical choice is provided I cannot justify another type of battery than the good old lead acid flooded type.

[ruddycrazy]

Well regarding sealed gel batteries,

                                    4 years ago i found at a scrap yard 30 off 6 volt 110AH sealed batteries, I got the lot for $240 and they are still used as my main bank in my shed. I can use my brdgeport for hours and they hardly every drop too much voltage. As far as overvoltage goes I've had homemade charge controllers burn out and the batteries have hit 32 volts, did that hurt them NO.

                                    On our house array we have 12 2 volt 600AH sonnenschiens that have been going for over 5 years now with no problems.

                                  Sure with the brass monkey weather you blokes get wet cells might be better for the climate but for me I'm happy with sealed batteries.

Cheers Bryan

[fishfarm]

I too am in the "cheaper is better" camp and am using Sams Club 6V lead-acid golf cart batteries (now into their third year).

My reasoning is that all the efforts being made to improve battery technology will, at some point, actually result in a better battery. I don't want to have just bought some high-dollar conventional batteries when they finally come available.

[TomW]

shine;

Well, if I learned anything in the last 9 or so years in this addiction is that new folks should probably buy "cheap" batteries to kill while they learn. It took me about that long to flat out kill my original 8 Trojan 105's which are 220 amp hour 6 volt flooded lead acid cells .

We just upgraded to something a bit tougher and bigger as well as more expensive. I posted a Diary on that upgrade over here:

http://www.fieldlines.com/story/2009/1/30/161351/147

I learned a lot over those years but the batteries paid for it. By the end they were only returning 10% or so of the input. My first setup was 12 volts with a cheap inverter that claimed to shut down at 11.5 battery volts. It actually shut down at 10.5 which I didn't catch until it happened a couple times. My mistake and it likely shortened their life considerably. The lessons were learned so it was like paying for "lab supplies" in college just the cost of educating yourself.

Just another point on batteries for new folks.

Good Luck with it.

Tom

[Chuck]

There is no best kind of battery, only the best one for your needs, budget and abilities. All of them need to be treated well to survive very long. This requires knowledge, diligence and luck.

AGMs get a lot of grief from folks who don't understand them. I've been using some large telco style AGMs for 8 years with no noticeable change in capacity.

I'll agree that if you're just going to be playing with cheap stuff that probably isn't going to work right, then don't risk good batteries on it. But if you're looking for something that you're going to treat with knowledge and respect, AGMs are a good choice, especially if you can get them (barely) used for a good price.

Chuck