[peloflex]

Dear friends,

I have been required to replace a back up battery like the one shown in the attached picture. I have done some exhaustive search on the subject in this forum and I have found useful information, however there is still a some doubts. First of all, why do we have a resistor wired in like the original battery? What is this for? What if I do not put the resistor in?
Second question, Is it really ok to use 4 D cell batteries to replace the original one on a temporary basis? I have noticed that the back up batteries for the servo amps have already being replaced with 4 D cell batteries, but this one if for the main CPU board, since the machine seem to be losing parameters every time they power it down. Thank you! Merry X-mass!

[Jim Dawson]

The 390 ohm resistor is for current limiting. Just keeps the current flow under control. I would install the resistor on the new battery. You should be able to find one of those batteries at any hardware store. Just carefully solder the wires to the new battery. Try not to get it too hot.

[peloflex]

Thank you so much!! I am on my way now. Cheers!

[CitizenOfDreams]

Batteries do not like heat, so it is best to find one with solder tabs or wires. If you do have to solder the battery itself, do it quick with a large and hotter than normal soldering iron.

The resistor, as Jim said, limits the current and prevents battery explosion in case something shorts out on the board.

What is the voltage of the original battery? If it's 3 volts, then it can be temporarily replaced by 2 alkaline cells in series.