Quote:
Originally Posted by The_bluester
I have been using a cheapo jump starter pack for the last couple of years. When it was new it would comfortably run my CPC925 all night without any issues (But without any dew control) but it's capacity is falling away now. It was a cheapie though.
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Apologies if you already know this, but those starter packs aren't deep cycle - they're typically designed for sparse usage and 5-10% discharge, similar to a car battery, though I'm guessing that the starter packs are likely to use the cheapest and nastiest battery available.
Deep cycle batteries are designed for around 50% discharge (though some manufacturers claim 80% - I personally have trouble believing that), and if re-charged promptly, should (IIRC) manage 600+ charge-discharge cycles before losing noticeable capacity.
The main difference is in the plate construction - deep cycle batteries have heavier, solid plates with alloy components to stabilise them (with the effect of reducing maximum current), whereas high-current (car/starter pack) batteries use a lighter, honeycomb plates that maximise surface area but will suffer more rapid degradation if discharged deeply.
I sized my batteries for 8-hour sessions running worst case loads (where I calculated that discharge would not exceed 53% in one and 48% in the other). Alternatively, I can run average loads for two average nights in succession. Maybe it's overkill, but I'm confident of achieving 10+ year life (as they're sealed AGM batteries and I'm fastidious about re-charging).
Now excuse me while I go and re-arrange my sock drawer.
