Alternative Technology Assn Forums

1. 

   IrishPete
   Member

   I inherited some very large batteries from a friend, after he bought new ones for his off-grid property - 3 banks of 4 cells, so 2 volts each.

   I transported them to my buish block cabin, and connected them to a small solar panel.

   On the journey there, probably just the last steep hill, the lashings gave way and some of the batteries and cells fell over and leaked. I topped them up with distilled water.

   However, not surprisingly they are not charging fully - they're around 11v (out of 12 - I'm using them as a 12v power supply for now, 24 maybe in the future). There's enough power to run an inverter, so they're still useable for all that I currently want out there - a bit of light, a hifi, maybe eventually a TV and DVD player (there's no TV reception, so it will be DVDs only!).

   But I am wondering is there any easy way of rejuvenating them? New acid might be the way to go, but it would be a lot of acid, and it would also be very awkward to drain and refill them. As you can imagine, they weigh heaps. And what would I do with the old acid?

   Any suggestions from the hordes of experts out there?

   Pete

   Posted Sunday 24 Jul 2011 @ 12:53:11 am from IP #
2. 

   Diver
   Member

   I saw a product called Recharge Battery Revitaliser at the Lardner Park field day earlier this year. My knowledge of batteries is basic at best and I haven't used this product but intend to. As such, I cannot give a personal recommendation.

   The product appears to be from N.Z. as you will see in the attached link. The link lists Australian stockists. I have also noticed that it is regularly exhibited at the various field days here in Australia.

   http://www.recharge.net.nz/

   Posted Sunday 24 Jul 2011 @ 1:44:16 am from IP #
3. 

   Lance
   Key Master

   Ok, a couple of points. When you lose acid from batteries through spillage, you should always replace it with acid, not distilled water, otherwise you reduce the specific gravity of the battery and the capacity.

   I am very wary of battery rejuvenators. While I haven't tested them to know if they actually work, I know some of them contain cadmium, a highly toxic metal, so you take a moderately toxic lead acid battery and turn it into a highly toxic one.

   Posted Sunday 24 Jul 2011 @ 2:35:05 am from IP #
4. 

   Andy Chee
   Member

   There are also battery rejuvenators of the electronic kind, but they might also be dubious. The one I made from junk box parts *seems* to work. A very neglected 12V motorcycle battery that once would not accept a charge at all, now has 3.3V! (after 4 months of zapping!)

   Posted Monday 25 Jul 2011 @ 4:46:14 am from IP #
5. 

   rockabye
   Member

   If the batteries are very large, and the solar module is very small, then you will be waiting a long time for them to recharge fully, if ever. Good news is I have found a small solar module good for 'rejuvenating' batteries over the very long term.

   I'd recommend a boost charge with a petrol generator / charger or if that is not available connect them to your car battery, in 12V configuration, with long heavy jumper leads and run the car engine while observing the battery voltage. You should see if they come up to 14V as a car alternator will deliver up to 40 amps.

   To the see current state, SG or specific gravity, of each cell purchase a battery hydrometer and check each cell. Good cells will be 1200 + while dead cells will barely float the bulb. A fully charged cell has an SG of 1250 - 1270.

   Posted Friday 16 Sep 2011 @ 11:34:00 pm from IP #

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