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How to Repair a BP1 or BP1A Battery Pack

This photoseries decribes the successful restauration of a damaged BP1A battery pack. The pictures are provided by Denis Fortin.

STEP 1

The backside of the BP1A battery pack. Please notice that the BP1 is identical.
STEP 2

The NiCd-batteries are corroded. Time to replace them.

The cells ate toxid, please follow your local rules of disposal! 

 
STEP 3

A perfect source for replacement is a 3-cell cordless phone battery. These batteries use always cells with solder tabs.

 
STEP 4

Make sure that you use NiCd batteries with a typical capacity between 450mAh and 800mAh.

 
STEP 5

Most difficult step is cutting the plastic shell of the battery pack.

Watch your fingers!

 
STEP 6

Bend the plastic tabs carefully away and don't break them.

 
STEP 7

Remove the old batteries. TOXIC !

 
STEP 8

The shell could be dirty.

 
STEP 9

Carefully remove the metal tabs. You'll use them later again.

 
STEP 10

Check the polarity of the new battery pack. 

 
STEP 11

Bend the tabs of the new battery pack backwards.

 
STEP 12

Try the correct position of the battery pack in the plastic shell.

Watch the polarity carefully!

 
STEP 13

Cut two slots into the plastic wrapper.

 
STEP 14

Find the positions of the BP1 metal contacts. 

 
STEP 15

Solder the tabs of the new battery pack to the BP1 metal contacts.

Don't overheat the cells or melt the wrapping away.

 
STEP 16

Insert your restored batteries into the plastic shell.

 
STEP 17

Bend the two plastic tabs back into position.

 
STEP 18

Apply quick glue to seal plastic tabs to the shell.

 
STEP 19

Hold them in place until it takes.

 
STEP 20

A restored BP1A side by side with an old BP1.

 
STEP 21

The place of your restored battery pack is usually a SR-50(A), SR-51(A), SR-52, SR-56, TI-58(C) or a TI-59. 

 
STEP 22

Plug it in - charge it - switch it on.

IT WORKS !

Denis, Thanks!
Next time take the right numbers. It is simply SRQ(8).


Fineprint: This information was compiled carefully but we are not responsible if someone destroys his calculator or himself.

If you have additions to the above article please email: joerg@datamath.org.

© Denis Fortin and Joerg Woerner, May 25, 2002. No reprints without written permission.