Just a few remarks,
In case of 2 batteries in parellel with different internal resistance,
like in the case with a lead acid and a NiMH, the current will be
delivered by the one with the lowest internal resisctance, in this case
the NiMH. Simply said: the lead battery does nothing at all. Furthermore
there will be complications during charging. These type of batteries can
not be connected in parellel, not without extra circuits like diodes or
relays.
Furthermore, starters are calculated with the normal powerdrop in mind,
in other words, feeding them with 12 V at "unlimited" current could burn
the starter, especially in cold conditions.
Looking a bit further at the advertised method of assembling the NiMH
packs on http://flydma.com/batteries/index.html it seems, that they are
soldered together, and i very much wonder how long the joints will stay
reliable in vibrating conditions. If these kind of battery packs would
be used for redundancy (=safety?) they could fail at the worst moment.
Not such a problem in a model plane maybe, but surely not advisably for
manned aircraft.
Jos Okhuijsen
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