HP 54520A replace CMOS battery with alkaline

[neazoi]

Hi, an HP 54520A scope, uses a cr17450se CMOS battery, which is empty. Rather than replacing it with the original (I want to play it cheap and quick) can I use a set of standard AA cells in series there?
I guess the cr17450se is not rechargeable, so I do not see any problem on that...?

 

[betwixt]

You should be OK doing that. The original would be used for its long shelf life rather than capacity. Dont forget you will have to replace the AA cells regularly though.

Brian.

 

[neazoi]

You should be OK doing that. The original would be used for its long shelf life rather than capacity. Dont forget you will have to replace the AA cells regularly though.

Brian.

I think that alkalines have low self discharge as well. And the battery is used as a cmos backup, I do not think they will need replacing that often. Sore, it might not be decades, but they should last for a few years.

My effort now is how to remove the welded spot metal sheets from the current battery. Because in order to do it the proper way and desolder them from the PCB, requires removing all the main PCB assembly, unscrew connectors etc.
Maybe I can cut one side carefuly, lift the batter and cut the other site, at the PCB pads. It needs care so as not to ruin the board.

 

[crutschow]

My effort now is how to remove the welded spot metal sheets from the current battery.

Could you just cut off the battery tabs with a diagonal wire cutting pliers?

For longer life you could use a couple of C or D alkalines.
I assume you would use a battery holder for them for ease of replacement.

 

[neazoi]

Could you just cut off the battery tabs with a diagonal wire cutting pliers?

For longer life you could use a couple of C or D alkalines.
I assume you would use a battery holder for them for ease of replacement.

Yes I have a socket for 2 AA in series. I managed to attach this at the ventilation holes (there are many holes) at the back of the scope with 2 screws, so no drilling was required. There is lots of space there. 2 small cables go to the previous battery strips. These were removed from the previous lithium terminals using a destructive method, but still attached to the PCB pads. These terminals cannot be soldered, so I clamped the cables to these by bending them.
The scope works not, previously it did not boot at all and this was due to the empty cmos battery.
However the scope needs to be re-calibrated now. I have no idea how tough this would be, I have to look at the manual...

 

[crutschow]

These terminals cannot be soldered

Have you tried?
I've soldered to the steel tabs on batteries previously without problem.
You should be able to if you apply flux before doing the soldering.