Is it socketed or soldered to the board?
Some of the DS1287 clone chips didn't do the epoxy trick and you can just pop the top off and replace the dead battery with a new one.

My personal rule is to Dremel "in place" any device soldered to the PCB. I'll also Dremel any 48T02.

Reasons:
I'm less likely to cause damage using a Dremel compared to desoldering. For the 48T02 (not relevant here) it's because early devices have undocumented features which preclude replacement with later devices (even when the data sheets say they should work).

jmarsh wrote on 2025-09-28, 01:53:

Is it socketed or soldered to the board?
Some of the DS1287 clone chips didn't do the epoxy trick and you can just pop the top off and replace the dead battery with a new one.

(Soldered) Shit, I didn't know you could do that unfortunately already ordered the replacement, but I think it's worth seeing if I can just replace the battery that way instead of desoldering it. (The thing hasn't even shipped yet, so it'll save me a lot of time.. 😦)

jmarsh wrote on 2025-09-28, 01:53:

Is it socketed or soldered to the board?
Some of the DS1287 clone chips didn't do the epoxy trick and you can just pop the top off and replace the dead battery with a new one.

What exactly do you mean by "popping the top off"? Cut it open?
And as for the battery, what would that be? A CR1632?

chickenvog wrote on 2025-09-28, 22:10:

What exactly do you mean by "popping the top off"? Cut it open?
And as for the battery, what would that be? A CR1632?

On some of the Dallas clones, they're not a solid lump of epoxy inside - the bottom is the RTC chip with a crystal and small battery sitting on top of it, with just a plastic shell glued lightly onto the sides of the chip. You can tell easily enough by squeezing the sides towards each other; if they flex there's just a void inside and you can likely pry the outside shell off with a little bit of force.

Otherwise if it does feel like a solid lump you can do the dremel thing - but unlike most of the guides/videos out there, keep in mind you only need to expose the positive battery terminal (rather than making two holes for both positive and negative) because the negative terminal simply connects to ground which can be found anywhere on the board.

jmarsh wrote on 2025-09-29, 02:27:

chickenvog wrote on 2025-09-28, 22:10:

What exactly do you mean by "popping the top off"? Cut it open?
And as for the battery, what would that be? A CR1632?

On some of the Dallas clones, they're not a solid lump of epoxy inside - the bottom is the RTC chip with a crystal and small battery sitting on top of it, with just a plastic shell glued lightly onto the sides of the chip. You can tell easily enough by squeezing the sides towards each other; if they flex there's just a void inside and you can likely pry the outside shell off with a little bit of force.

Otherwise if it does feel like a solid lump you can do the dremel thing - but unlike most of the guides/videos out there, keep in mind you only need to expose the positive battery terminal (rather than making two holes for both positive and negative) because the negative terminal simply connects to ground which can be found anywhere on the board.

Squeezed it, and it's solid unfortunately, but my drop in replacement on the way so that's good news. In any case I can try the dremel trick. Thanks!