flecc, in your AA pack experiments, you have Schottky diodes to connect the battery stacks when using them, and you switch these out for charging.
You also talk about charging two stacks in parallel. What did you do to stop transfer currents in this case? Or are you assuming that if both stacks are discharged any cross currents will be low and will be short lived?
What about using low value resistors to balance them for charging? Or can we assume that the voltage drop of diodes is not enough to confuse a 36 V charger?
Nick
**WARNING** 2/2/08 I'm adding this warning for anyone coming to this thread later. One of our members had a battery fire while parallel charging.Battery fire. The exact cause is yet to be determined but useful precautions to take would be:
Ensure that the trickle charge current for NiMH cannot exceed the safe level for the cells in any circumstances.
Use something that detects a temperature rise and terminates the charge
Do not leave charging batteries unattended.
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You also talk about charging two stacks in parallel. What did you do to stop transfer currents in this case? Or are you assuming that if both stacks are discharged any cross currents will be low and will be short lived?
What about using low value resistors to balance them for charging? Or can we assume that the voltage drop of diodes is not enough to confuse a 36 V charger?
Nick
**WARNING** 2/2/08 I'm adding this warning for anyone coming to this thread later. One of our members had a battery fire while parallel charging.Battery fire. The exact cause is yet to be determined but useful precautions to take would be:
Ensure that the trickle charge current for NiMH cannot exceed the safe level for the cells in any circumstances.
Use something that detects a temperature rise and terminates the charge
Do not leave charging batteries unattended.
****************
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