2.4V battery pack for Proto 2

This would be a better alternative….

https://www.jandwelectronics.com/bcr2

Tom

Except for that minor pesky difference between a female and male connector- it's exactly the same.........

VS

@Vernon Barry posted:

Except for that minor pesky difference between a female and male connector- it's exactly the same.........

VS

Oh come on Vernon....in this day and age with trans this and that, does M/FM really matter on something as simple as an electrical connection?? (the guy said to the fireman, right after the fire was put out...or the transistor burnt out!) Good catch. Greg

@CALNNC posted:

Amazon sells a 2.4V 700MA battery pack, a Kruta BT162342 complete with what looks like the proper connector that will fit my MTH Proto 2 E3.  Its dimensions are very close, actually a tiny bit smaller than the pack in the loco now.  Has anybody used these instead of trying to get one from MTH?

Clip the wires and connector off the old bad battery and solder them onto the wires of the new battery and you should be good to go.

This is much simpler.

@John H posted:

This is much simpler.

About the same amount of work but I do agree with this solution more. Never worry about dead battery replacements again. The only downside is the OP's batteries are a little cheaper than a BCR, but the maintenance-free factor is worth the little bit of extra cost.

I cut the leads off the old battery and solder them to a supercap.  For five minutes work and a $1.50 supercap, I have the battery replacement for 3V PS/2 boards.

Thanks for all the input on the battery.  Thought the battery was bad or discharged when I read .5 volts getting to the remote charge terminal.  This loco was purchased used, and while all the bells and whistles were fine, the loco did not move.  (Maybe that was the reason it was a bargain) I charged the battery and it came back 100% and held its charge, but still a no go.  When sitting with track volts up, pushing the direction button, that shut the loco down and it rebooted every time.  What I found was a bad battery female connector in the wiring harness, not passing battery volts to the engine.  Fixed that and now works like a champ.  In research about supercaps and not wanting to spend 30 bucks for a premade supercap, I found supercaps for sale at Newark Electronics for $1.84 each in lots of 10.  2 needed to make a 9 volt unit, and one for a 2.4 volt unit, but will wait until I have a bigger order in the offing as shipping is $10 minimum .  Why did MTH decide on 2.4 volts on some and 9 volts on others?  Is it all due to the IC's needed volts, some are CMOS?

@CALNNC posted:

Why did MTH decide on 2.4 volts on some and 9 volts on others?  Is it all due to the IC's needed volts, some are CMOS?

The original PS/2 board was using 5V logic, and there were some shortcomings in the design.  Specifically, it appears that many of the components were running near the edge, and then there's the bad capacitors.  Also, the 5V boards were permanently joined together, so you couldn't get to many of the components to do component level repairs.

The redesign of the PS/2 board was the 3V logic board, that was a 2-piece design that IMO was a much better design.

Thanks John for the battery volt info and its evolution.