Ed writes me about properly forming a recent NiMH purchase.
Hi Dave,
I recently bought one of the FDK Twicell 6.0V 5-cell 2000mah NiMH AA Flat Pack and would like to try it in one of my airplanes . I read all your comments about this battery pack and I have the HiTec Multi-Charger X-4 and not sure what is the best way to charge it. The charger is fairly new in my collection and I am still learning the best way to use it any thoughts?
Thanks,
Ed
Ed,
The best way to do it on most computerized chargers is:
General procedure,
1. Go into setup, make sure the mah limiter and time limiter are both off.
2. Put charger in PB mode, yes for Lead acid.
3. Set charge rate to 100mah, any more will ruin the battery eventually.
4. Set voltage of battery to 8V
5. Start charger.
If it refuses to start, set voltage to 6V and let it run a minute or two, the go back and restart with setting at 8V
“Generally” Eneloop’s (Twicell’s) come to you about 1/2 charged. So, the hole your filling is about 1000mah. (Hole * 1.4) / charge rate in mah = time in hours. 14 hours in this case.
What we are doing with the procedure above is tricking the charger into functioning like a dumb wall wart where it will just plod along indefinitely until we disconnect the battery.
The best practice would be to connect the cells to a dumb charger that charges at 50mah for about 30 to 40 hours and is the ONLY method for which I would ever consider warranting a pack. People try to break in new batteries in peak detection modes all the time which is the cause of my slightly “acidic” warnings against such acts on my website. One issue is there are no makers of chargers like that that I know of in the hobby world today. The last one (Sirius) seems to have become inactive. The best chargers to own for this forming purpose at this time are an ACE DDVC, ACE Digipulse or Sirius Pro-Former. Should you run across one at a swap meet or on Ebay, snap it up.
Dave
