my cheapo off grid system

[Raul]

Are they OPZs type ? If they are then you can get good deal . Normally they get replaced over here when 80% life left in them . If recondition even better.

[almac]

used , would be taking a punt , i could only check the SG and voltage b4 buying

[Mike90250]

What sort of warranty will the dealer give you on used (not even re-conditioned?) fork lift batteries ? I'd be very wary. No, I would run away !

[SunEagle]

What sort of warranty will the dealer give you on used (not even re-conditioned?) fork lift batteries ? I'd be very wary. No, I would run away !

They make great door stops for small trucks.

[almac]

battery update

hi guys, havnt logged in for a while, thought i would update how my cheapo off grid system is progressing . have been researching the reconditioning of batteries. after plenty of reading i have found that batteries are best left chemically unaltered. so that means if they respond to a steady charge of around 14.4v over a few days without the lead plates collapsing , they are ok. i went to an auto wrecker and bought some batteries for scrap value. about $10au each. 50% of them were serviecable. i got the good ones to 100% soc with a trickle charge over a few days. the bad ones had some collapsed cells, the electrolyte was black and the SG was off scale. so i assumed the plates had collapsed into the solution giving a very high SG. no loss because i got my money back on those for scrap at the scrap metal yard.

so here are some pics of my battery bank. it is now made up of 8 batteries ,2 sets of 4 x 4 in series for a 24v 325amp hour bank. 2 of these batteries were $10au each and perform as well as the new ones. no reason all the batteries could not be made up of the junked $10 batteries. another $10 battery is a 200amp hour trojan . also good. nearly up to 90% soc after 3 days. should be 100% by 2mor. it was dead flat when i got it and the top of the plates were exposed.

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[PNjunction]

have been researching the reconditioning of batteries. after plenty of reading i have found that batteries are best left chemically unaltered. so that means if they respond to a steady charge of around 14.4v over a few days without the lead plates collapsing , they are ok.

Not necessarily. You can charge a totally sulfated battery up to 14.4v, and it may seem to hold a charge initially but not over time - or at least not once any load the battery was designed for in the first place was applied.

There is a lot of quackery out there. However, in your case, I can heartily recommend a Tecmate-Optimate 6 charger for those zombie 12v batts. Obviously the best thing to do is purchase new and treat them right. But since it seems like you want to play with recovery, the Optimate 6 in my experience has been the best so far. Most importantly, the test-result you get back will quickly show if you are making progress, or just wasting time! Charge them individually *without* being connected to any other gear for the best results for recovery.

If you want to take it even further, a Battery-Minder should also be applied if the Optimate does a recovery first. With the Minder, it is going to take at LEAST 72 hours before seeing any result. Many poo-poo the Battery-Minders *frequency, not high-voltage* technique, but I have seen some limited success (not total!) with some batteries.

I hesitate to mention this, since for me recovery is usually a waste of time. Usually. But if you have a steady supply of junk, and a lot of spare time on your hands, then either of these two, or both (but NOT at the same time) will do the best job - and most importantly, are honest about telling you when it is time to QUIT and just throw in the towel on a particular battery.

The Optimate 6 would be the leading candidate to apply first as it truly a serious tool (well, as far as you can take it without lab equipment). Then follow up with a Battery-Minder for those on the edge. In all cases, it takes TIME - ie let them actually finish their charge / test cycles.

Also, aside from doing repetetive load-testing, you may want to baseline and document the IR, aka internal-resistance of the battery and you can see if there has been any improvement, or if they are getting back close to manufacturer spec. This can be done at the hobby level with the iCharger line of hobby-chargers. Unlike some others, they don't need to be under charge to take this measurement. I personally use an iCharger 306b for this task. Being dc powered, one usually uses a power supply, but it will also run from one of your many other 12v batteries too. Of course it has it's own charging algo's for various chemistries, but you can just use it solely for taking internal IR measurements if you don't want to use it for actual charging duties.

[bcroe]

had a pm requesting to know more about my off grid system so here are a couple of pics . [ATTACH]7327[/ATTACH][ATTACH]7328[/ATTACH]

You need those panels clear of the ground. Any grass blocking the bottom rows of cells will
affect your whole production. Bruce Roe

[almac]

You need those panels clear of the ground. Any grass blocking the bottom rows of cells will
affect your whole production. Bruce Roe

thanks, yes iv noticed the amps drop off alot with just a tiny bit of shade. i mow it when it needs mowing.

[almac]

found an auto wrecking yard that will supply as many batteries i can use. scrap value prices. bought another 4 at $6 each nothing wrong with them. the terminal lugs cost more at $10 a pair so am using tie wire. when these batteries fail can get my money back at the scrap dealer, so far the other batteries are still ok been going for 8 months. so now i have free solarDSCN0002.JPGDSCN0003.JPG.

[Mike90250]

I see you making friends with the fire department soon.

(And getting a new floor when the acid drips ruin that one)

[almac]

thanks for the warning, shall look for a bulk deal of terminal lugs online

[Bala]

Really!!!!!!!!!! You are just one spark away from a big bang.

I would hazard a guess you are running everything 240V off that inverter with no RCD or correct fuse protection, earthing.

Your battery set up and your 240V system are just plain unsafe.

Your free power obviously does not include all the hours you spend driving around getting batteries and swapping out the dead ones etc etc,

and must also factor the risk to people coming to your house unless no one ever does, then its just you.

[almac]

hi bala, the inverter cuts out if there is an overload so from the inverter its safe isnt it?, point taken about the tie wire being a heat/ fire risk. time spent driving around?? i live in suburbia so within a radius of 15km there are about 10 auto wreckers, these batteries should last at least a year since i dont deep discharge, run heavy loads in the day, so a larger bank will cover the problem of cloudy days. so tell me what i can do to make this safer apart from getting the correct terminal lugs

[SunEagle]

That looks like an accident that is past due from happening. I hope no one smokes in that room.

[almac]

seriously fire has been a concern for me,it has crossed my mind as i add more and more free batteries,, i have given a thought to moving this bank outside, so proper terminal lugs , iv thought about fusing the inverter cable? if that shorted it would melt , any advice is welcome