On 17/11/13 17:16, Anthony Anson wrote:
Can increasing (lead-acid) accumulator capacity overload the charger circuitry?
In theory it might but you'd probably get away with it to a reasonable degree. Pb batteries are supposed to be charged constant voltage so in theory doing things like running packs in parallel would lower the series resistance and thus make the charging circuit work harder. Though I think on heavily discharged packs the charger starts off CC and then moves to a CV model once some base charge is in.
In practice a lot of the APC UPS' are designed to deal with additional battery modules so you might get away with it.
Couple of things though
Charging parallel packs isn't good..running/charging parallel packs of different age/type/capacity is very bad. Running a bigger battery or packs in series to make up the correct voltage is better than two packs of the right voltage in parallel, generally UPS's tend to run batteries in series to make up a higher voltage if they have multiples.
You might confuse the life out of any capacity monitoring circuit, though I'd expect anything good to be using a coulomb counter which should cope.
Charging leisure type batteries and Pb "Gel Cells" as used in UPS kit is different. I think putting a leisure battery on a gel charger is better than the other way round but I'd check on that before you explode yourself due to excessive venting from the pack :-)