Batboard

When programming ht50's or P100's, for power during this I have a spare radio case for the 10 volt batteries these radios run on. As the P1225 radio needs the same type of battery block, how much resistance would I need to put in line to safely use the 10 volt battery to program the 7.2 volt P1225, or, could I get away with the 10 volts for just programming? Thanks in advance.

NO, you need 7.5 volts for the P1225, and GP series radios.

Not sure why you have 10 volts. So you NEED a voltage regulator to regulate the 10 volts to 7.5 volts.
A LM317 - 1.5A Adjustable Positive Regulator three lead is what most of us use. Set to 7.5 volts.



Technical Information - National Semiconductor LM317T Datasheet

http://www.futurlec.com/Linear/LM317T.shtml

Why wouldn't you just stick the P1225 in the programming charger cradle with a battery on it?

Some aftermarket batteries do not have the programming connection in them.

Will wrote:Some aftermarket batteries do not have the programming connection in them.

I would never have thought of that, since I never use an aftermarket battery. Thanks!