N Cell Rechargeables!

[Gene]

I have a set of N cell rechargeable NiMH's and a set of rechargeable N cell NiCD's. I also have a Maha 401 charger. I made a set of "extenders" for use of these in the Maha 401 for N cells. They both came up "green" in the Maha charger and that meant these cells were totally charged.

I have a lambda "NanoMate" that works wonderfully with store bought N cells. I tried the NanoMate with these NiMH and NiCD rechargeables. None would work. I then put a "blob" of solder on the tailcaps and tried them again. Still, no dice!

Anyone have any advice as to why the store bought alkaline N cells work perfectly and these rechargeables do not?

 

[RussH]

How many cells does it take? The rechargables are only 1.2-1.3v. Could that be a problem? What did you use for extenders? A resistor in series with the NiCDs or NiMH batteries will make the charger think they were at a higher voltage (battery voltage + resister ohms x amps = total voltage at charger output).

I really like my Maha 401. But I would use my Maha 2A4
http://www.thomas-distributing.com/maha-mh-2a4.htm for trickle charging these (with your extenders). It charges at 50ma or 80ma depending on how you load the batteries. I use it to top off batteries from other chargers, including the MH401FS. The 50ma current won't harm anything even if you leave them on there for an extended period (they recommend 2 days max). HTH, -RussH

 

[Gene]

Russ,
I also thought that maybe my homemade extenders were tricking the 401 to think they were charged when they weren't. It IS charging them fine though. I've "sort of" found the problem. For some reason the rechargeables are not grounding properly to the NanoMate pill. They appear to be the exact same size as the alkaline N's but evidentally they're not. I put a small amount of tin foil around the pill and they all are now working albiet not very reliably. I have to unscrew the head a lot farther to get it to turn off and I used only a very tiny bit of aluminum foil for the ground. I'll have to come up with a better solution.