Re: (ET) batteries

["David Roden" <etpost drmm net>]

On 7 Feb 2022 at 22:57, Chris Zach via Elec-trak wrote:

> I think I'm on 22 years with my pack now. BB600's may not have max power
> density, but they are on the road to lasting "forever".

Good NiCd cells can be pretty long-lived.  The chemistry is totally 
different from lead's - the electrolyte is just an ion carrier - and the 
wear and degradation mechanisms are slower.  

Most (not all) flooded NiCds can take a surprising amount of abuse, 
including moderate overcharging, though I know of someone who destroyed a 
whole pack of rare Saft STM5-180s by putting them on a big charger and 
forgetting about them.

Even cell reversal isn't instant battricide as it is with lead.  There's 
no 
analog to sulfation.  Undercharging doesn't harm them. 

They can be stored in any state of charge, and in fact with cells (not 
batteries) the preferred storage method is to first run them flat.  Some 
even suggest storing cells (not batteries) shorted.  Unlike lead, they 
won't freeze until you get to Artic temperatures.

Unfortunately, they're expensive and hard to get when new, and the once-
plentiful supply of surplus BB600s seems to have dried up in the mid-2000s.

Disposal is also a problem when they finally do croak.  Cadmium is nasty 
stuff and illegal to landfill.  Most battery recyclers won't accept 
flooded 
 NiCd batteries or cells.  It's almost impossible to buy NiCd in the EU 
for 
this reason.  

Probably the most sensible thing to do with them when they no longer work 
well enough is ship them back to the factory, pay to have them rebuilt, 
and 
put them back to work.

At >= 25 years old, my East Penn Deka Dominator gel batteries have also 
held up surprisingly well, though not as well as your BB600s.  In recent 
years, they've finally started to decline in capacity and I've lost half 
of 
the 24 that I bought used in 1998. Most of the remaining ones are now down 
to 50-60% of rated capacity.  Still, that's not bad at all for lead 
batteries of that age.  


David Roden - Akron, Ohio, USA

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