One of my Ryobi 14.4 packs is dying. It has 12 NiCad sub-Cs spot welded. Any
tips, hints, warnings for replacing with tagged cells? This pack has a third
wire coming off a chip / temperature sensor? on the first cell.

In article ,
Newshound wrote:
One of my Ryobi 14.4 packs is dying. It has 12 NiCad sub-Cs spot welded.
Any tips, hints, warnings for replacing with tagged cells? This pack
has a third wire coming off a chip / temperature sensor? on the first
cell.

If you were happy with the original (Ryobi seem to make decent and budget
stuff) I'd first price up a replacement. It's often cheaper than
re-celling. Of course if it was a poor battery to start with, decent cells
will transform the performance of the drill. Found that out with a PPPro
one.

No gotchas with using tagged cells - just make the joint as quickly as
possible with a hot clean iron. The temp sensor is usually just glued or
taped in position - put it in the same place on the replacement.

--
*I started out with nothing, and I still have most of it*

Dave Plowman London SW
To e-mail, change noise into sound.

Newshound wrote:
One of my Ryobi 14.4 packs is dying. It has 12 NiCad sub-Cs spot welded. Any
tips, hints, warnings for replacing with tagged cells? This pack has a third
wire coming off a chip / temperature sensor? on the first cell.

If you've got a meter you will probably find just one or two of the
cells have gone s/c. Did a complete rebuild job on a hitachi battery
pack and was fine for light drilling work but as soon as you started to
apply more of a load the soldered battery connections melted! Remade
the connections twice (I'm an electronic eng. so I know how to solder
before anybody throws that in) then threw the battery pack in the bin!
- would have been a good repair if I could have got them welded somehow.

In article .com,
wrote:
Did a complete rebuild job on a hitachi battery
pack and was fine for light drilling work but as soon as you started to
apply more of a load the soldered battery connections melted! Remade
the connections twice (I'm an electronic eng. so I know how to solder
before anybody throws that in)

Err...

then threw the battery pack in the bin!
- would have been a good repair if I could have got them welded somehow.

They are welded to prevent heat build up to the cell which may occur while
soldering, and damage the cell.

A properly made overlapping solder joint will happily carry more current
than the tags themselves. I've done hundreds without problems.

--
*Why are a wise man and a wise guy opposites? *

Dave Plowman London SW
To e-mail, change noise into sound.

Dave Plowman (News) wrote:

They are welded to prevent heat build up to the cell which may occur while
soldering, and damage the cell.

A properly made overlapping solder joint will happily carry more current
than the tags themselves. I've done hundreds without problems.


Indeed - there is no way those tags are meant to reach 160C + in normal
operation. Something was definitely wrong there, to cause the soldered
joints to melt.


--
Grunff

"Dave Plowman (News)" wrote:
In article .com,
wrote:
Did a complete rebuild job on a hitachi battery
pack and was fine for light drilling work but as soon as you started to
apply more of a load the soldered battery connections melted! Remade
the connections twice (I'm an electronic eng. so I know how to solder
before anybody throws that in)

Err...

then threw the battery pack in the bin!
- would have been a good repair if I could have got them welded somehow.

They are welded to prevent heat build up to the cell which may occur while
soldering, and damage the cell.

I keep meaning to actually make a little mock-up of a cell (strong salt
solution on the inside of a thin steel plate, with a thermocouple on it)
to find out exactly how hot they get when using my preferred technique.

(basically clean very thouroughly, tin (0.5s) then attach a wire (0.5s))
The place where the wire is can be touched in under 2 seconds easily.

(I've posted a much more detailed explanation several times in the past)