Third-party Li-ion circuit board

Olympusman · Post by **Olympusman** » Mon Apr 13, 2015 9:58 am

Circuit board for a third-party "Canon" BP-511. I was surprised to see oxidation on a battery I had just cut open.

rjlittlefield · Post by **rjlittlefield** » Mon Apr 13, 2015 10:06 am

Do you know the date of manufacture?

--Rik

Olympusman · Post by **Olympusman** » Mon Apr 13, 2015 2:37 pm

Rik,
No date on the "actual" Canon battery or the third-party battery. The actual Canon came with a Canon G3 I bought online for my camera collection, which crashed ( battery issue?). The actual Canon battery was rated at 7.4V 1300 mAh 9.7 wH (watt hrs?) and marked "Europe only".
The third-party was rated at 7.4V 2000 mAh. This difference plus the design of the "logic" circuit board that manged the performance of the Li-ion cells may have fried my G3.

Mike

mawyatt · Post by **mawyatt** » Mon Apr 13, 2015 5:08 pm

Mike,

Many years ago I ran across a lot of NiCad batteries that had leaked due to overheating the terminals. Surprisingly, the best soldering method utilizes a large iron with lots of thermal mass to heat the terminal quickly. This keeps the heat from propagating into the battery terminal and breaking the seal, since the iron is in contact with the terminal only a short time.

Anyway, this might be the case here for the corrosion. It looks as though the assembly is not very precise as you can see by the center terminal flat wire not centered. I have seen some horrible looking circuit boards from cheap sources, yet beautiful looking boards on hard drives....well beautiful to me being an engineer :>)

g4lab · Post by **g4lab** » Mon Apr 13, 2015 10:15 pm

Usually NiCd batteries are not soldered, they are spot welded. The spots are small and sometimes multiple with cooldown time in between. The stainless steel doesn't like to accept solder. and the batteries don't like the heat.

mawyatt · Post by **mawyatt** » Tue Apr 14, 2015 6:44 am

g4lab wrote:Usually NiCd batteries are not soldered, they are spot welded. The spots are small and sometimes multiple with cooldown time in between. The stainless steel doesn't like to accept solder. and the batteries don't like the heat.

Agree, but these NiCd batteries had the spot welded tabs but the other ends were soldered to the circuit board, they were very short also. I figured that since the batteries all leaked at the seal either the seal was bad (unlikely) or that too much heat had been applied to solder the tabs to the circuit board....probably due to using too small a soldering iron. Anyway, the solution was simple, replace the batteries and use a heat sink clip on the tab at the battery terminal..and use a big heavy iron!!

Olympusman · Post by **Olympusman** » Tue Apr 14, 2015 9:10 am

I agree the soldering on this unit is pretty sloppy. And the D2 and P1 contacts look like they may be cold joints.

Mike

Olympusman · Post by **Olympusman** » Tue Apr 14, 2015 9:10 am

I agree the soldering on this unit is pretty sloppy. And the D2 and P1 contacts look like they may be cold joints.

Mike

ChrisR · Post by **ChrisR** » Tue Apr 14, 2015 9:19 am

We call 'em dry joints. It's interesting to see them sectioned under a scope.

Third-party Li-ion circuit board

Third-party Li-ion circuit board

"Canon" BP-511

Re: Third-party Li-ion circuit board

Circuit board

Circuit board