On 01/05/2011 23:50, Dwayne Reid wrote:
> For me, the greatest charging differences between Lead-Acid and
> Lithium Ion are:

Established & simple 90 year old charging technology (14V Power supply +=20
resistor works!), also newer low/zero maintenance "Calcium" technology=20
appears to have a sharp knee at "fully charged" enabling cease of charge=20
and thus avoiding electrolysis of water to H and O. Getting 4 to 5 years=20
from Automotive batteries seems feasible.

vs

Great balls of fire... Even if the design is correct and either you=20
accidentally  install wrong model cell, cell is punctured (the LiPoly=20
ones in bags) or cell is faulty. Lithium life seems suspect too, though=20
may depend on exact type and usage (I never get more than a couple of=20
years on laptop, but my Sony Camera 8mm digital tape battery is very old=20
and still does 5hrs).

In my experience you only have to high current or deep discharge Gel=20
Lead acid once or twice and it's scrap. NiMH and NiCd don't mind being=20
left flat, it destroys lead acid. The longest life Lead Acid for actual=20
regular use seem to be regular automotive "Calcium" zero maintenance=20
type. Gels will last maybe twice as long as automotive if charged  and=20
not actually used! (i.e. good for Alarm panel backup etc).  The Gel Lead=20
Acid do appear to have very low self discharge, better than Automotive=20
Lead Acid. Modern cars of course take power all the time even when off,=20
so for long periods off the road the battery may need to be disconnected.

High capacity NiMH seem more finicky than Lead Acid or NiCd or "low=20
capacity" NiMH as they appear to require near zero trickle charge and=20
seem to have significant self discharge.
--=20
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