Yes, the IR thermometer will show a lower temp on the outside of the case than the cells are actually experiencing. However, it won't be too far off, and since the charger stops the rapid charge cycle at about 104 degrees Fahrenheit, a few more degrees one way or the other won't really make much of a difference. The temperature rise is also fairly slow, as in several minutes per degree even when the battery finally reaches full charge, so the thermal lag is minimal, even though the plastic doesn't transfer the internal cell temp very well.
Bob M. ====== --- On Mon, 8/11/08, Albert <[EMAIL PROTECTED]> wrote: > From: Albert <[EMAIL PROTECTED]> > Subject: [Repeater-Builder] Re: Genesis series bank charger question > To: Repeater-Builder@yahoogroups.com > Date: Monday, August 11, 2008, 10:04 AM > Thank you all for the input. As always, I can trust that > this group > has a wealth of distributed knowledge. > > Allow me to respond to a few of your suggestinos and > comments. > > I did look through my P200 Radius manual (don't have it > handy or I > would write down # of manual) and found a small section in > the back > describing the theory of opperation regarding the bank > charger. There > was also a schematic and expoded diagram. It was very > enlightening. > The six slot charger is much more complicated than I > thought. I am > glad I took digital circuits or else I would have been > lost. > > Thank you Mike for your comments on Bob's article. I > had a feeling > that was the case. As I have researched, experiemented, and > learned a > little more I came to the same realization. Either you > could modify > the charger or modify the resistor and thermistor in the > battery. I > guess manufactures have finally picked up on that and begun > to > install different components in the packs. > > So, this raises another question. Monitoring battery > temperature > while charging. I guess the IR thermometer would be ok but > I immagine > the batteries inside the shell would be a bit hotter than > the outside > of the case. What would be a better way of monitoring > battery > temperature in order to determine if the battery was > charging > properly or not? > > I guess I will leave the charger alone for now since the > circuitry > seems different enough from the desktop fast charger that > the same > modifications can't be made. Also, as stated above, the > modifications > may not be necessary at all. > > Thanks as always. > > Albert > KI4ORI > > --- In Repeater-Builder@yahoogroups.com, Mike Morris WA6ILQ > > <[EMAIL PROTECTED]> wrote: > > > > At 04:14 PM 08/10/08, you wrote: > > >Hey guys, I am back with yet another Motorola > Genesis series > question. > > >I have acquired a 6 slot bank charger and would > like to convert it > > >over to handle NiMH batteries. I have done both my > stand alone fast > > >chargers and my MVA, but not the bank charger, but > I immagine it > > >shares at least some similarities with the others. > I was wondering > if > > >anyone would mind offering guidance? > > > > > >Thanks. > > > > Note that the mod listed in Bob's article was > required because of > > the different thermal response of the NIMH cell > chemistry, and the > > fact that the manufacturer of the particular > batteries Bob received > > used the thermistor intended for NICDs. > > > > Different manufacturers may use different thermistors. > In some > > cases no mod may be needed. > > > > At one time the local Radio Shack had their hand-held > remote IR > > Thermal readout device for $20. I wish I had > purchased one then, > > but by the time I heard about it they were out of > stock. > > See > <http://www.radioshack.com/product/index.jsp?productId=2460852> > > One of these would making the measurments mentioned in > Bob's > > article very easy. > > > > Mike WA6ILQ
