Eero Ahonen <aer### [at] removethiszbxtnetinvalid> wrote:
> scott wrote:
> >> NiMH -batteries can't deliver enough current IIRC,
> >
> > NiMH should be fine for current, they are used in electric vehicles
> > after all.
>
> That's the one I wasn't sure about, therefore IIRC :).
>
> > I suspect the main drawback of NiMH is that it self-discharges pretty
> > quickly compared to lead acid.  Your car might not start after leaving
> > it for a few months, which would be unacceptable to most car makers.
>
> Might be. Anyway, it has such great disadvantage compared to lead acid
> on this matter, it's not used :). We can be sure that car manufacturers
> and battery manufacturers have calculated it.
>
> -Aero

The main advantage of lead acid batteries is they can be charged with constant
voltage where other batteries like NiCd, NiMh, LiIon or LiPo need specialized
charge electronics to limit the charge current and monitor the cell voltage.
Not so for lead acid. The only thing you need in the car is a voltage regulator
which regulates the output voltage of the alternator to roundabout 14V and the
battery is happy.
Also: Lead Acid Batteries like it if they are fully charged against for example
NiCd thad lose capacity very quickly if you have them laying around fully
charged.

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