Charging NIMH batteries

NodrogCop · Post by **NodrogCop** » Wed Apr 10, 2002 5:19 pm

Can you charge NIMH batteries in "traditional" chargers, or do you need special ones? I have a Saber I on the way with a pocket charger, and was looking at getting a NIMH battery. I just need to know if I should look for a new charger also. Thanks for any help.

I'm excited about the Saber -- it'll be my first. I'm supplementing my M-PA's.

Gordon

Hightower · Post by **Hightower** » Wed Apr 10, 2002 9:13 pm

The one NIMH battery that I have (purchased new) has a sticker that said to only use a rapid 2-hour charger. This battery is for the Astro Saber.

Tom in D.C. · Post by **Tom in D.C.** » Thu Apr 11, 2002 4:59 am

Most of us have found that NiMH batteries charge just fine in NiCD chargers. The battery that you can NOT charge in these chargers is the Lithium Ion (LiON).

Re Hightower's comment about using only a two-hour (fast) charger, the fact is that most if not all Saber chargers (EXCEPT for the Porta Pocket) ARE fast chargers.

Tom, W2NJS
...in D.C.

USPSS · Post by **USPSS** » Thu Apr 11, 2002 5:58 am

Only one problem with NiMH batteries in regular rapid chargers, some chargers will only give the battery about 80% of total capacity, I have seen that on the larger 6 unit old saber chargers, not always though. I have that combination and I also have a Cadex unit and it confirmed it to me.

Stan

NodrogCop · Post by **NodrogCop** » Thu Apr 11, 2002 11:34 am

Thanks for all the feedback - it's much appreciated.

Gordon

April · Post by **April** » Thu Apr 11, 2002 3:44 pm

And don't forget that ALL the Red LEDs are on all the time at the "house", NYPD Blue Saber rack charger.

NiMetal Hydride batteries can ONLY be RAPID charged in a charger that monitors the batteries voltage and terminates the charge on a Delta V. Most Rapid or Dual Rate monitor a thermistor in the battery and reduce to the "trickle" rate of 1/10th C when the NiCad battery gets real hot, NiMH do not have the temp sensor in them, to my knowalege.

NiMH batteries can be charged in any slow charger with a rate lower than 1/8C, most slow chargers are 1/10th C. But you have to leave them in the slow charger for a longer time because the NiMH have more capacity and take will "longer to fill up". Same is true for the "fat" batteries like the HT1000 series 1500maHr guys, so I have to modify the slow charger so it will "fill up all the way" the fat batteries in 14 hours.

Jonathan KC8RYW · Post by **Jonathan KC8RYW** » Thu Apr 11, 2002 4:23 pm

Just wondering, does anyone know the thermister types used in M battery packs?

Will · Post by **Will** » Thu Apr 11, 2002 6:06 pm

The thermistors I have seen are glass encapuslated and are about 12 k ohms cold, going down to about 5 k or less hot.