Originally Posted by ctsbillc
It will take a while for this new technology to come online. Meanwhile, the prices of the large phosphate cells has become very appealing. Twice the price
is very do-able, and the weight savings are huge.
Are these betteries from Mastervolt and others lots of parallel smaller cells?
The Mastervolt, Genasun, RaceCell, etc. are 4 cells in series for 12V, or 8 in series for 24V. The "nominal" charged voltage per cell is usually considered 3.2V or 12.8V for a typical 12V pack. The individual cells are actually 3.6V to 4.2V at max charged voltage (depending on the manufacturer), so actual max voltage of 4 in series is roughly from 14.2V to 16.8V.
For higher voltage systems (EV's or electric
propulsion), there is the option to put many individual cells in series to get to the higher voltage, and then put the subsequent larger groups in parallel; or to put as many as possible in parallel first.
A small example of this in a 12V pack:
For a 300Ah x 12V pack, you could do either: 3 x 100Ah x 12V groups in parallel, each consisting of 4 x 100Ah 3.2V cells in series (which is the same as hooking up 3ea 100Ah regular lead/gel/agm batteries in parallel). Or, you could do FOUR groups in SERIES, each consisting of THREE cells in PARALLEL....the net result is the same. Either way you get 300Ah x 12V