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Old September 17th 04, 07:01 PM
Eric F. Richards
 
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(Mark Zenier) wrote:


Bzzzzzt. You were doing fine up to there. Unless you are addressing
alkaline (Ni-Cd) batteries instead of Lead-acid batteries


Er, alkaline batteries are primary cells usually, except for those doggy
Rayovac rechargeables.


Ni-Cds are alkaline, too, and I'm not talking about "D" cells, dummy.
Wet cell Ni-Cds with sodium hydroxide electrolyte and a layer of
mineral oil keeping the electrolyte from being exposed to air are used
in a fair number of systems. They're used in locomotives to start
them. Ni-Iron (Edison) cells are in those boxes at every crossing.

Ni-Cds are dangerous as hell, but handle temperature variation much
better than lead acid.

Bzzzt. All chargers are solid-state, PWM based.


Not if you build your own. (Or dig back and look at a few magazine
construction projects).


All *modern* ones. And a store-bought PWM charger can be had for $30.
And there are designs out there for build your own.

And if you're just hacking around, you probably won't want to spend
the $$$ for one if it only gets you from 50 watts to 80 watts.


If he's using lead-acid and the panel cannot charge faster than C/5,
he can do without a controller altogether. Probably don't want to do
that with a gell cell unless the rate is C/20 or so.

--
Eric F. Richards,

"Nature abhors a vacuum tube." -- J. R. Pierce, Bell Labs, c. 1940