Author Topic: Batteries, help a newbie  (Read 5490 times)

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Offline jamie aust

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Batteries, help a newbie
« on: September 29, 2014, 07:05:35 am »
Hello All,
This is my first solar install and I'm looking for some help.
I have 9x 250w panels, 2x pmmt chargers, going into 8kw inverter, input 24v dc out 240 Ac .
I would like to know what brands are good in Australia, I already know what volt / amps hours I need.
I know if a battery has a CCA keep clear of them. A lot of deep cycle batts can be misleading also.
Any thoughts on golf cart batts?
Batt bank will be 24v and as many amps as I can.
Best bang for buck is what I'm after.
Thanks
Jamie

Offline gww

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Re: Batteries, help a newbie
« Reply #1 on: September 29, 2014, 12:13:56 pm »
I am a usa guy but believe some here are from where you are.  You might also post on (thebackshed) website.  Ask them what they use.  I believe some here also frequent that site but it might widen the exposer of you question among those who should know. 
Good luck
gww

Offline oztules

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Re: Batteries, help a newbie
« Reply #2 on: September 29, 2014, 03:36:50 pm »
The best bang for buck will come from Trojan T105 series.
They are the "holden car" of batteries... ie common, and probably the best value for money.

The T105-RE are slightly better from a RE perspective, as the plates are even more robust, and they are physically bigger to carry more water.. less  maintenance.

The best technology for a newbie is most probably wet batteries ( flooded), as there is far more chance of recovering from over charging and a myriad of other faults that can occur with your own system.

Your solar can charge maybe 3-4 strings of 24v batteries with a c10 charge.. or 80A for a bit of the day anyway.

You will in every likelihood ( like most of us do) , kill your first bank off earlier than you should as you learn to maintain a battery bank and get your system finalized and working the way you anticipated, and thats another reason to not use an expensive fancy technology first off.

So the RE version of the T105 is probably favorite, but any golf cart battery will give excellent service if you find some other brand MUCH cheaper... otherwise a few dollars more for trojan is probably money wisely spent.

In a previous life I bought many hundreds per year for floor scrubbing machines, and in that industry, Trojan  seemed to be the battery of choice throughout the industry in Melbourne at least.


......oztules
Flinders Island...... Australia

Offline jamie aust

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Re: Batteries, help a newbie
« Reply #3 on: September 29, 2014, 05:01:50 pm »
I can get my hands on some Rejuvenated 12 volt Deep Cycle Battery Golf Cart batts, (T-1260) 3 month warranty up to 85% of new battery capacity.

My question is, how do I tell when this type of battery is no longer any good and need replacement ? Should I be looking at its fully charged voltage as the key ?

Offline gww

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Re: Batteries, help a newbie
« Reply #4 on: September 29, 2014, 07:06:52 pm »
Just my opinion,  I never have luck with warranty new or used.  Some of the new if not bought at a close location want you to ship the battery to them.  New warranty is usually 80 percent of capacity.  That makes 85% close to bad.  They would have to be really cheep.  I bought 7 batteries for $10 each.  Four ended up being good enough to use.  One exploded when put under a heavy load.  That was pretty dramatic.  Just something to think about.  No matter what you buy you need to know what to charge it at.  Give it a good charge then equalize until sg's quit rising and write the sg's down for every cell then you will know what you started with and when that changes.
gww

PS  most don't use 12 volt bats for re, they use 6 volt or 2 volt cells,  also a warranty sucks if you have to use it, usually everything has to be disconnected maybe not used then reconnected.  If you just want to play, used is fun but if you need to rely on it maybe not so much fun although if cheep enough it is good to test stuff with.

PS PS  I can still sell the ten dollar battery that blew for ten bucks even if it cost me 20 bucks in gas to get it to the salvage yard.

Offline jamie aust

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Re: Batteries, help a newbie
« Reply #5 on: September 30, 2014, 05:19:30 pm »
As this is my first go at RE, I dont want to waist money on things that just dont work.
I also want to be able to learn ( play ) with some cheap batteries first, just in case I do something wrong....
This is what I can get here in Brisbane, Australia.
Used 6v / 220 AH $109 each ( am I correct that I should stay clear of these then ? )
New Apex ( Trojan ) 6v / 220 AH $180 each
New Trojan T105 6v/ 225 AH $208 each

24V bank

Im looking at a bank of 4 in series first, then put another bank of 4 in Parallel with the first bank.
If others could reply with what brand they use, that would be helpful for me.

thanks

Offline MadScientist267

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Re: Batteries, help a newbie
« Reply #6 on: October 01, 2014, 11:09:49 pm »
Jaime -

I'm not a seasoned vet just yet, but well on my way as a wannabe... that said, I'm running a pair of RayOVac SLIGC125s currently, 6V/235Ah, nominal 12V. They've been good to me, this will be their third winter and they're still enduring, bought them as a set, new.

There are mixed stories about used batteries out there... personally that's the one component of the system I avoid used like the plague... it's difficult to near impossible to determine the remaining health without putting them thru their paces a couple times and seeing how they react.

Just my take on it, from learning the hard way on earlier smaller systems. Some report fantastic success, I'm not one of them.

As Oztules pointed out, new or used is an easy kill for the first go round... even as forgiving as flooded is, it still has it's limits. That said, I agree with the sentiment of at least using flooded. Sealed cells (AGM/SLA) are much less tolerant of abuse.

For what that's worth ;)

Steve
Wanted: Schrödinger's cat, dead and alive.

Offline tomw

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Re: Batteries, help a newbie
« Reply #7 on: October 02, 2014, 07:16:33 am »
I will certainly agree that most folks murder a set or two of batteries before they get dialled in on how to treat them. Flooded Lead Acids are pretty forgiving but I believe most are killed by their inexperienced owners.

I certainly would not suggest a high cost starter bank. to anyone. Having said that I would suggest the Trojan T-105 or equivalent. Relatively common and somewhat tough. Or a used traction (forklift) set if t is the right price.

Your Mileage May Vary

Tom
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Offline philb1

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Re: Batteries, help a newbie
« Reply #8 on: October 03, 2014, 10:41:29 am »
I started out with two new Trojan T105 batteries years ago. They to were murdered. Overcharged, undercharged, ran low on water until the plates were showing and still lasted 1 1/2 years.

As an alternative, EverReady GC2 6 volt golf cart batteries IMHO are just as good and about the same price as the T105's. Mine were manufactured by Johnson Controls and relabeled with an EverReady sticker. That's what I have now on one solar setup. 

Wherever you get your batteries new or used, I would buy several gallons of distilled water and a hydrometer or refractometer at the same time. Some type of battery terminal sealer is also an item I keep on hand.

2.25 kW of solar is a hefty system for starting out. You will need several batteries for that much solar.

Offline jamie aust

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Re: Batteries, help a newbie
« Reply #9 on: October 03, 2014, 03:41:53 pm »
Thank you everyone for your reply.
I will go with new T105 or the Apex clone new also. ( one bank of 4 )
A  few liters of distilled water, hydrometer, and battery terminal sealer, all noted  :)
I have all the parts now accept the inverter ( should be here next week ) and Batteries.
I hope to be able to test it in about 4 weeks or so, when its all installed.

jamie