Re: parallel packs?

[darrylmcmahon igs net]

Putting in diodes could work - there are automotive battery 
isolators for essentially this purpose for RVs - that way both 
batteries charge, but the starting battery does not drain when the 
accessory battery is used.  Don't know if the isolators are rated to 
36 volts.  Drawback is the voltage drop over the diode, about 0.6 
volts which is a few watts at a 100+ amps.

You could also use contactors to put the batteries in parallel only 
when desired and leave them isolated otherwise.  Unless there is a 
bad cell in one of the packs, charging in series should not be a 
problem - each pack will take what it needs to get up to charge.  I 
would recommend golf-cart solenoids, they are rated for continuous 
duty - automotive starter solenoids are not.  Golf-cart solenoids are 
available in both 12-volt and 36-volt coil (actuator) circuit variations.


Darryl McMahon             48 Tarquin Crescent,
 It's your planet.         Nepean, Ontario K2H 8J8
 If you won't look         Voice: (613)828-0805
 after it, who will?       Fax:   (613)828-3199