Battery for American Arium ML4400 logic analyzer

[OldieButGoldie]

Hello,

I bought an American Arium ML4400 logic analyzer on eBay.

The device basically works, but (as usual with such old equipment), the (important) NVRAM storage does not work
There seems to be little to no information on the INET about this device. The only information I could find, was an old thread on this forum (https://www.eevblog.com/forum/repair/arium-ml4400-logic-analyser) with an link to the operating manual and some rom files (was very helpful though).

So I opened it to replace the battery. As I thought, the battery was completely flat and also started to leak. Fortunately no traces or components have been damaged
But unfortunately, the search for an replacement battery is more complicated than I thought, because they used an unusual type (see attached pictures). It was manufactured by Plainview, and it's part no is PMB 2.4 B.
There are not many referenced on the INET about this type , but I finally found some information in an old PostScript document about a "RT284 mass memory cared". Basically it seems to be an NICD pack with an Voltage of 2.4V. But there are no information about it's capacity, and also no datasheets.

My questions are:
- Does anyone know this type of battery? Have datasheets?
- Can it be replaced by an 2.4V NIMH battery, without modifying the charging circuit?
- Has anyone a service manual for the American Arium ML4400 logic analyzer?

[Haenk]

So that's 2 NiCd cells in one hotshrink case.
As the cell needs to be soldered in, you might want to try something like this:

https://www.ebay.de/itm/153877726128

(I'm in no way attached to this seller, probably other and better offers out there - but you get the idea...)

[OldieButGoldie]

Thanks for the reply Haenk
Yes, I already thought of something like that. But without a datasheet from the original battery, I can only guess it's capacity.
And with no schematics from the charging circuit, I just don't know, if using a higher capacity could impact it's performance.
Probably, I just have to try some random 2.4V NICAD battery, and see if this works in the long run.

[Haenk]

I don't expect any complex charge logic being implemented (probably none at all), a small capacity (smallest you could find) should work flawlessly as a replacement.