T&T: 24V backup charger...

[Steven Dubnoff]

>Thanks for all of the excellent 24v charging ideas.  OK, so using
>2-12v chargers in series probably isn't a good idea because of heat
>build up.  I agree with that.


Don't connect them in series, connect one twelve volt charger to each 
battery.  The chargers will not know the batteries are in series, 
they will only see the 12 volts on each battery.  In fact, you can 
argue that two 12 volt chargers are better for your batteries than 
one 24 volt charger because it keeps the batteries equalized. In the 
electric vehicle community, where they care about these issues 
because a dead battery means a walk home, the preferred way of 
charging large series-connected banks is with many commodity 12 volt 
chargers, each connected to one battery in the bank.

If this is for backup, buy two electronic chargers (The Vectors are 
good - I think they are rebranded as Black and Decker 
also).  Actually for your thruster batteries, you can get by with 
one, charging them one at a time.

Best,

Steve