GBZ, I don't mind being the battery 'Agony Aunt', I have asked many questions here in these fora and many nice people have been kind enough to answer them, some in great detail. I am simply returning the favour.
Anyway, I basically agree with westy on this.
Gel and acid should mix reasonably well together as long as normal parameters are maintained i.e., mixing a gel and a lead acid battery in a car system shouldn't be a problem at all - as in west lake's experience.
Interestingly you can also mix batteries of differing capacities together if need be, the theory being that as the combined batteries work together (as opposed to individually). The different sized batteries simply add up to one larger unit and charge/discharge together.
Or to put it another way, if you have three 12V batteries, lets say:
1 x 75 Ah;
1 x 95 Ah;
1 x 130 Ah;
and join them all together in parallel, they will then act like one big 12V battery of (75+95+130) 300 Amp hours.
Or, if joined together, when battery A is at 77%, then battery B and battery C will also be at 77%.
As I said in my post above, the main concern with a gel battery is that you don't exceed its charge/discharge capacity.
An interesting case in point is a product we have here, known as a "Thumper Pack", marketed by Waeco. These are sold as a high capacity battery unit for jump starting, or deep cycle applications. They are a very capable product and can jump start a car or truck or run a fridge for a couple of days. Most folks assume that they are a gigantic battery inside, however in reality they are simply 4 modest SLA batteries of approx 65 Ah, all wired up together and packaged inside a tamper proof box. (So the punters can't see all the "trade secrets" inside!)
Cheers,
ABX
Last edited by ABX; 27th Jul 2007 at 07:59.
Reason: To fix a mistake, thanks balsa!