Repairing/replacing cordless tool battery packs…

[cosmopedro]

Hi guys!

I have an old (maybe 2003 or earlier?) Senco DS-202 cordless 14.4V drywall screwgun that gets used a lot for short periods of time, then not at all for long periods - think 6-8hrs/day for two consecutive weekends then idle for months or years - and I just dragged it out for said weekend, plugged batteries into charger one at a time and got ‘bad battery’ indication… I have no intention of replacing the gun - at replacement prices not worth the trouble - but it works so nicely I don’t want to use my corded DeWalt drywall gun.

Does anyone have any experience with rebuilding them? I saw a clip on YouTube where a guy bought replacement sub-C’s and soldered them together, and that’s a path I think I can manage since aftermarket replacements run north of $50 and rebuilders are similar price point but replacing sub-C’s is half that…

Any/all feedback appreciated EXCEPT the “throw it away and buy a new one” type… as stated above it’s just not worth it to me. I’m just trying to figure out if I’m poking a hornet’s nest by going this route?

Thanks in advance, y’all!!

 

[dogdog]

Just be careful about buying sub-c off Amazon or Ebay. Not all of them are created equal.
Nickle strips can be bought there by the roll no problem, I think they sell a version Sub-C ones come with tab...

Buy from a reputable source is all I can say, and if the capacity sounds ridiculous probably a fake one. Have that happened to me when I wanted to rebuild the craftsman 19.2V, didn't work out. They are supposed to be matched capacity or you will shorten the life of that pack with one ore more cells die and causing short.

The other option is check if thingiverse have a battery adapter from your other platform to your Senco. that way at least you can use the newest li-ion and still use that old tool... odds are not in your favor though senco is not a popular brand for tinkers.

 

[Outahere]

...... aftermarket replacements run north of $50 and rebuilders are similar price point but replacing sub-C’s is half that…

$50 is reasonable, if high quality cells are used. DIY soldering of wire or tabs onto batteries can damage the cell with excessive heat. Use a low temperature solder to speed up the process. A spot welder is preferred.

soldering batteries

 

[WWheeler]

I know not really an option the OP requested but perhaps worth considering if there's access to a 3D printer.

Senco 14.4v to Dewalt 20v battery adapters

These adapters allow you to use 20v Dewalt lithium batteries on 14.4v NiCd Senco tools. I have had these tools kicking around for a while and there have been a few jobs where they could have been really handy but because of the extra weight of lugging around multiple brands of batteries with...

cults3d.com

 

[RTM]

Or these guys?

Professional Battery Assembly, Rebuilding, and Repair - MTO Battery

Get high-quality service on battery rebuilds, battery repairs, and battery reconditioning on Segway, Power Tools, and specialty batteries. We specialize in batteries from Fluke, 3M, Fitel, Fujikura, Snap-On, EGO, DeWalt, Milwaukee, Akron, Trilithic, JDSU, Trimble, Sokkia, Leica, Cleco, Profoto...

www.mtobattery.com

 

[cosmopedro]

Based on time availability (mine) and cost, I’ve decided to have them rebuilt… will post success/failure rate when I’ve used them a few times.

 

[cosmopedro]

I know not really an option the OP requested but perhaps worth considering if there's access to a 3D printer.

Senco 14.4v to Dewalt 20v battery adapters

These adapters allow you to use 20v Dewalt lithium batteries on 14.4v NiCd Senco tools. I have had these tools kicking around for a while and there have been a few jobs where they could have been really handy but because of the extra weight of lugging around multiple brands of batteries with...

cults3d.com

I’d be interested IF:
A). Someone would print them for me…
B). They were Makita LXT-to-SENCO adaptors…

I don’t own any DeWalt cordless.

 

[cosmopedro]

Based on time availability (mine) and cost, I’ve decided to have them rebuilt… will post success/failure rate when I’ve used them a few times.

SO, after shipping them off to @RTM - suggested rebuilder (MTO) and having them rebuilt for less than expected ($81.50 for 2 batteries) and returned quickly, I topped off the charge and these puppies act like new batteries! Can’t thank @RTM enough for the suggestion and MTO batteries enough for top-shelf service!!

 

[BukitCase]

Cosmo, I'm in the same boat you WERE in with my Senco "full auto" screw gun - when your batteries came back, were they still NiCd or did they upgrade 'em to Lithium? ... Steve

 

[cosmopedro]

Cosmo, I'm in the same boat you WERE in with my Senco "full auto" screw gun - when your batteries came back, were they still NiCd or did they upgrade 'em to Lithium? ... Steve

Y’know, I didn’t even look - just plugged’em into charger, let’em charge and put’em to work.

I’ll check tomorrow & report back…

 

[BukitCase]

Cool, thanks

 

[LSU]

I’d be interested IF:
A). Someone would print them for me…
B). They were Makit

I used MTO for my 30+ Makita 9.6v rebuild. I was happy with the results.

 

[rslaback]

Cosmo, I'm in the same boat you WERE in with my Senco "full auto" screw gun - when your batteries came back, were they still NiCd or did they upgrade 'em to Lithium? ... Steve

If they didn't blow up when he had them on the same charger the most they could have done was upgraded to NiMh.

 

[cosmopedro]

If they didn't blow up when he had them on the same charger the most they could have done was upgraded to NiMh.

There ya go, then… no explosions! Didn’t have time to look, will try in between work hours tomorrow.

 

[dnschmidt]

MTO is a quality outfit. I've used them for Metabo batteries.

 

[cosmopedro]

Cosmo, I'm in the same boat you WERE in with my Senco "full auto" screw gun - when your batteries came back, were they still NiCd or did they upgrade 'em to Lithium? ... Steve

Aaand we have a winner! NiMH it is… and VERY professionally done!

 

[BukitCase]

Did your rebuilder mention anything about NOT using your old NiCd charger with NiMH batteries? From this

BU-408: Charging Nickel-metal-hydride

Chargers utilizing the step-differential or other aggressive charge methods achieve a capacity gain of about 6 percent over a more basic charger. NiMH…

batteryuniversity.com

"The differences in trickle charge current and the need for more sensitive full-charge detection render the original NiCd charger unsuitable for NiMH batteries"

That site is the most comprehensive battery info site I've ever seen - not for the faint of heart, but if you can't find answers THERE, they likely don't exist -

Learn About Batteries

Battery University™ is a free educational website offering hands-on battery information.

batteryuniversity.com

For all the "skimmers" out there - sounds like the old charger will work, but may shorten the NiMH life by maybe 20-25% and should NOT be charged UN-ATTENDED (confession - I too "skimmed" parts, that site can cause your eyes to roll back in your head) ... Steve

 

[cosmopedro]

Did your rebuilder mention anything about NOT using your old NiCd charger with NiMH batteries? From this

BU-408: Charging Nickel-metal-hydride

Chargers utilizing the step-differential or other aggressive charge methods achieve a capacity gain of about 6 percent over a more basic charger. NiMH…

batteryuniversity.com

"The differences in trickle charge current and the need for more sensitive full-charge detection render the original NiCd charger unsuitable for NiMH batteries"

That site is the most comprehensive battery info site I've ever seen - not for the faint of heart, but if you can't find answers THERE, they likely don't exist -

Learn About Batteries

Battery University™ is a free educational website offering hands-on battery information.

batteryuniversity.com

For all the "skimmers" out there - sounds like the old charger will work, but may shorten the NiMH life by maybe 20-25% and should NOT be charged UN-ATTENDED (confession - I too "skimmed" parts, that site can cause your eyes to roll back in your head) ... Steve

Partial response from MTO:
“To start, both chemistries have the same charging voltage so the charger voltage algorithm would not be an issue. The difference of the delta v peak that NiCad and NiMH batteries do when fully charged. NiCad cells have a more pronounced voltage spike when fully charge when compared to NiMH. With our NiMH cells, the difference is less of an issue because we had these cells produced specifically for use in NiCad power tool chargers. That said, the manufacturer modified the cell design so that this is not an issue. On top of that, the charger is also constantly monitoring a temperature sensor inside of the battery and also reduces the current and shuts off based upon that variable as well.”

I’m not worried - if I was using every day and batteries were running through multiple charge cycles per day, I might feel differently.

YMMV!!

 

[BukitCase]

Wow, sounds like the positive comments about MTO are UNDER-STATED - 'WAY COOL... Steve

 

[ddawg16]

Unless the battery packs are Li....I wouldn't waste the money.

All my stuff is Ryobi.

When I first started using them, they have NiMH batteries. Now they are Li.
What was smart on their end...they made the new Li replacement battery packs in the same form factor and voltage.

Li is so much better.

NiMH is 1.2 V/cell
Li is 3.5+ V/cell

Ryobi put the battery management circuit in the battery pack...hence, you could charge Li packs with the old chargers.

If you don't use NiMH or NiCd batteries on a regular basis, they will go bad. They also self discharge at about 10%/month.
Ni? They can sit for a year or more and it doesn't bother them. Self discharge is about 1%/month or less.

Most of the Li packs use the 18650 Li cell

 

[Wyoming09]

Another +1 for MTO battery. Had some Dewalt 14.4 batteries rebuilt. Well worth the investment.

 

[cosmopedro]

Unless the battery packs are Li....I wouldn't waste the money.

All my stuff is Ryobi.

When I first started using them, they have NiMH batteries. Now they are Li.
What was smart on their end...they made the new Li replacement battery packs in the same form factor and voltage.

Li is so much better.

NiMH is 1.2 V/cell
Li is 3.5+ V/cell

Ryobi put the battery management circuit in the battery pack...hence, you could charge Li packs with the old chargers.

If you don't use NiMH or NiCd batteries on a regular basis, they will go bad. They also self discharge at about 10%/month.
Ni? They can sit for a year or more and it doesn't bother them. Self discharge is about 1%/month or less.

Most of the Li packs use the 18650 Li cell

You kind of missed the point I originated with - but no biggie!

My only concern w/Ryobi is that the first 2 tools I used of theirs - maybe a decade ago - were j.u.n.k. so I never went back. Prolly not the best approach but I can’t say that about the Bosch/DeWalt/Milwaukee/Makita/Metabo (oh, and SENCO!) tools I own, so there ya go.

I know - I’ve just opened the floodgates to haters and tool experts alike… I don’t care.

 

[PugetDude]

Unless the battery packs are Li....I wouldn't waste the money.

All my stuff is Ryobi.

When I first started using them, they have NiMH batteries. Now they are Li.
What was smart on their end...they made the new Li replacement battery packs in the same form factor and voltage.

Li is so much better.

NiMH is 1.2 V/cell
Li is 3.5+ V/cell

Ryobi put the battery management circuit in the battery pack...hence, you could charge Li packs with the old chargers.

If you don't use NiMH or NiCd batteries on a regular basis, they will go bad. They also self discharge at about 10%/month.
Ni? They can sit for a year or more and it doesn't bother them. Self discharge is about 1%/month or less.

Most of the Li packs use the 18650 Li cell

This was ddawg16's last post on the GJ? Did I miss something?