I have a schematic of another unit that seems to match mine. I'll check out the end-of-charge signal. Maybe I can increase the gain of the circuit so it detects the smaller signal better.
I guess I was hoping someone else had "been there, done that" and found a cure. Maybe I'm the first? Thanks. Bob M. ====== --- "John J. Maurer" <[EMAIL PROTECTED]> wrote: > Bob > > The rapid charge rate is probably fine - the problem > normally is that the charger does not stop the > rapid-charge cycle properly. As you probably know, > the negative slope dv/dt is significantly less for > NiMH chemistry than for NiCd chemistry. You > probably have the schematic - can you see how the > end-of-charge signal is generated? Another > possibility would be to adjust the overtemp cutoff > downward - although I've never liked that method it > would protect your packs. > > The GP300 rapid charger also suffers the same > problem. A buddy of mine got a new pair of NiMH > GP300 battery packs last year, after the battery > vendor assured him the stock charger would work > fine. His packs also got warm during the rapid > charge cycle. They lasted about 9 months before > they were toast. He ended up going back to NiCd > packs. > > 73, > John Maurer WØDP > Ames, Iowa > > > ----- Original Message ----- > From: Bob M. > To: repeater-builder@yahoogroups.com > Sent: Wednesday, March 28, 2007 8:48 AM > Subject: [Repeater-Builder] OT- Motorola NTN4633B > Charger for NiMH batteries > > > I've got a pair of UHF HT600s that now have NiMH > battery packs. The NTN4633B charger was made for > NiCd > packs and while it does seem to charge the NiMH > packs, > the charger and the packs get alarmingly hot. > > Is there a modification to this unit, or maybe I > need > a completely different unit, to rapid-charge these > NiMH packs properly? I think some of the MT-series > radios use the same battery (10V, 1100mAh NiCd, > 10V, > 1700mAh NiMH). > > Thanks. > > Bob M. > > > __________________________________________________________ > Food fight? Enjoy some healthy debate > in the Yahoo! Answers Food & Drink Q&A. > > http://answers.yahoo.com/dir/?link=list&sid=396545367 > > > > > > ------------------------------------------------------------------------------ > > > No virus found in this incoming message. > Checked by AVG Free Edition. > Version: 7.5.446 / Virus Database: 268.18.18/734 - > Release Date: 3/26/2007 2:31 PM > ____________________________________________________________________________________ The fish are biting. Get more visitors on your site using Yahoo! Search Marketing. http://searchmarketing.yahoo.com/arp/sponsoredsearch_v2.php
