old mth 8.4v Nimh 120 mag battery replaced by tenergy 9v Nimh 200 mah batteries- engines lock up 5 of 6 times

bucca posted:

old mth 8.4v Nimh 120 mag batteries were replaced with tenergy 9v Nimh 200 mah batteries by me. my 20 engines are all mth premier original protosound, not proto 2 or 3. The engines sat on shelves for 10 years because of  of my health (severe spasms in my back). the mth z4000 bought new, never used, also sat in box in bedroom closet. after replacing the batteries, engines seem to lock in programing mode 5 of every 6 tries, lock up as if you try to start them w a dead battery that scrabbles the chip. But then they will 1 of 6 times, run ok. yes, I know about the dead battery scrabbling the electroniucs chip, even have the chip replacement kit sold by mth. anyone have experience with replacing the $11 mth battery 120 mah with new 9 volt batteries ($4 per battery).

I use tenergy 9v Nimh 250 mah in both protosound by QSI and also protosound 2, have no problems. Been using them over 10 yrs, Vic.

If I remember correctly, raising the voltage too high at startup will keep the engine in reset. Are you familiar with that procedure?

John, I did not know raising the voltage too high at startup will keep an engine in reset. I will try lower startup voltage. The 4 protosound QSI engines I tried before doing my post all seemed to go into reset                                                                                                                                                                                                                                                                                                                                                              and thank you vic, I was very nervous using tenergy 9v 200 mah as replacement batteries. I will proceed slowly with so many (20) protosound QSI engines. 

I think the number is 10 volts or less. Once out of reset you can pour on the coal.

John nailed my only comment, works on all my "older"stuff.

I've used consumer NiMh batteries in PS/1 and 5V PS/2 for years, I've never had any issues.  As long as you use the 7-cell batteries (most common), you should have no issues.  I don't recommend you go with Lithium 9V batteries, the charging curves are all different.  NiMh and NiCad are compatible with the charging circuit of those locomotives.