I've been using the 1 amp NIMH Tenergy chargers and I just had another one go bad. This time it was my fault by accidentally reversing polarity when connecting it to the battery. I'm looking for a better quality charger, but one that has the standard two lead output (+) and (-), not the three lead type that has a thermistor lead. Any ideas? I'd even build one from a kit if it was available....
Nexcell makes a 48 volt nimh charger for ebikes. It charges at 2 amps instead of 1 amp though. It may still be available through ebikes.ca
Falconev also sells the chargers but I think they may only have 24V 4A versions which would require electrical isolation from each other to use simultaneously to charge at 48V pack.
Yes, I had seen that charger on that web site, but unfortunately it has the 3-pin output requiring the thermistor on the pack. I had bought a similar charger, made by Hi-Power, when I my bike was running at 36 volts. I couldn't figure out how to make it work without the thermistor and couldn't figure out how to wire in a thermistor on the pack. I wound up returning that charger (bought from powerstream.com). If anyone can draw me a diagram or explain how to wire in a thermistor I'll be in good shape....
wiring the thermistor is nice and easy. Attach one end to the negative of the battery lead and the other to the third pin. tape or glue the thermistor to the middle of the pack or if you can't reach the middle then as central as possible. make sure you get the right thermistor for the charger, ebikes.ca sells matching thermistors on their site. I'd recommend as low an amperage charger as you can get. You can safely charge with high amp charger but its a bit more complicated as they can damage the pack through overheating if the pack is imbalanced, this sometimes happens if its been left for a long time.
Thanks for the instructions on how to wire it in. Sounds like it couldn't be easier. I was hoping for a 1 amp charger, because I feel the same way as you. It's a lot harder to damage a pack from a 1 amp charge. I have a double fail-safe since the AC receptacle I use has a 24 hr. timer built-in. I generally plug in before bed and set the timer to 8 hours and it's always fully charged by the next day. I know some chargers have an 8 hr. limit built-in but I don't think the Nexcell charger has it. BTW, the Nexcell is 2 amp I believe. Not what I was looking for, but better than 3 amp or higher....