MTH S2 diesel battery changeout

The 3V BCR is smaller than the original battery.  Given how tight things are inside the S-2 shell, you might find it easier to put everything back together again if you go with the BCR.

Edit / Correction:

S2 is the AAA pack, not the AA pack as linked.

https://www.mthpartsandsales.c...h/?type=serviceparts

Other places you suggested may have 2 cell packs, they are quite common- however also having the matching exact connector might be a different story. If you can solder, no big deal, just reuse the old connector.

Edit / Correction :

Below link is for the incorrect AA pack, not the required AAA smaller sized pack.

Also note, many forum sponsor dealers might have them too. Example Marios https://www.mariostrains.com/i...emart_category_id=15

@Vernon Barry posted:

https://www.mthpartsandsales.c...h/?type=serviceparts

This battery won’t fit the S2.  It needs the AAA battery.  The AAA pack that MTH sold was sub-par and no longer offers them.  A BCR will fir, but if you prefer a battery, I use a cordless phone pack available on Amazon and solder the correct end on the leads (observing the correct polarity). I’ve used dozens of these batteries with success.  Greater capacity, low self discharge.

BCR is the way to go!!

BCR2…

https://www.jandwelectronics.com/bcr2

Tom

Once the old battery is out, clip the wires off as close to the battery as possible reuse them and build your own BCR with a cheap super capacitor online.

Jon G writes:

“This battery won’t fit the S2.  It needs the AAA battery.”

Jon - OP’s photo confuses the issue for me. The printing stamped on the wrapper is “AAA”, but the shape sure suggests 2 AA batteries?

@Mark V. Spadaro posted:

Jon G writes:

“This battery won’t fit the S2.  It needs the AAA battery.”

Jon - OP’s photo confuses the issue for me. The printing stamped on the wrapper is “AAA”, but the shape sure suggests 2 AA batteries?

They appear the same, but the blue batts are AA, the green are AAA.

@H1000 posted:

Once the old battery is out, clip the wires off as close to the battery as possible reuse them and build your own BCR with a cheap super capacitor online.

I recognize that picture.