cordless tools/rechargeable batteries

[jonboy]

I now have a small collection of defunct cordless screwdrivers, drills, and now the latest victim, a Bosch hand sander.... I'm sure the problem is the batteries and I see , upon invasive surgery, the batteries are all linked by a thin metal bridge and folded up to fit whatever battery pack...Simply buying the new entire unit is always expensive( the little pack for a 3.6 V stapler I have is over 35 €) and often not available.. but individual batteries are, and not expensive, but I haven't had any luck joining them with soldering... is it a different technique required over standard electrical soldering... any ideas, tips, advice ???

[Breakaway]

There are firns ( at least here in the US) that will repack your battery packs for a fee. Also, check this thread for some good DIY info: http://forum.woodenboat.com/showthre...d-battery-pack

Kevin

[jonboy]

I have seen the above thread and see that most of the stuff I have has a battery pack that is torx or x head openable, so the issue is just the joining of the individual cells....and bundling them up inside the case...

The hand sander has the rechargeable batteries inside the tool as opposed to a plug in pack, and though the two batteries are joined with the spot weld strip, the terminals to the works are soldered so I am guessing easy to replace...

What about using off the shelf rechargeable batts from the supermarket, assuming I can rig a holder system.... Is it worth it though........????

[Breakaway]

Cost and time versus the cost of buying a replacement is a personal decision specific to the value and expected use for the tool. As far a rigging with off the shelf rechargeables, I dont know. Never tried it. I did convert a 12-v makita drill to work on a cord for use aboard my power boat --mostly as a polisher, since I'm at a dock without power. But that was worth the time and effort for me versus hand-waxing.

K

[seedy]

These folks DIY rebuild cores worked fine for my older Makita 18v. I moved up to NiMH and still can use the same charger. Takes a bit of doing, but several companies in the US can do it for you if you prefer that.

[Stiletto]

I have replaced batteries by soldering them into whatever configuration the pack requires.

A hot soldering iron with a large tip worked best for me. First I tinned the tops and bottoms of the batteries and the strips where the points of contact were. (Tinsmiths 50/50 solder with a dab of spirits of salts on the work. Dont use resin cored solder.)

The large tip on the soldering iron holds enough heat to immediately transfer to the joint without the heat being bled away as the metal takes time to heat up.

Once you have both the batteries and strips tinned with solder, it only takes a brief touch with the iron to establish a good connection.

Figure out how you are going to hold things while everything is cold.

Good Luck!

[Old Dryfoot]

You do need to be very careful to avoid transferring a lot of heat into the battery. Aside from shorting them out overheating is a sure fire way to kill a new cell. The type of pack you are describing has been spot welded for that very reason.

[The Gentleman Sawyer]

Batteries Plus can rebuild them

Ken

[Robert W. Long]

I had my batteries for a Makita and Panasonic drill rebuilt by these folks and am pleased with the result. They claim their rebuilt ones will be superior in power and lasting charge time and so far I have found this to be true.
http://www.primecell.com/pctools.htm

[Syed]

Can we see the batteries (link) we are talking about?

[Lewisboater]

http://www.duckworksmagazine.com/10/...b/06/index.htm

[jonboy]

Hi Syed... who...me?

[jonboy]

tanx for all the tips links and and pms guys.... would have been even better If I was on the other side of the big wet ditch...all the same I am going to try out various trix and let you know...jb

[Stiletto]

I look forward to hearing what works for you.

Good Luck.

[oldsub86]

I have looked at them too and my guess is that the connection is a spot weld rather than solder. It ought not to be too difficult to cobble together something capable of spot welding the thin metal strip to the battery. I wonder if it could be dangerous but assume that if done properly, it would only be a momentary application to the battery and as such likely no more dangerous than soldering. The factories do it so there is little reason that we cannot do it too.

Randy

[Old Dryfoot]

I have looked at them too and my guess is that the connection is a spot weld rather than solder. It ought not to be too difficult to cobble together something capable of spot welding the thin metal strip to the battery. I wonder if it could be dangerous but assume that if done properly, it would only be a momentary application to the battery and as such likely no more dangerous than soldering. The factories do it so there is little reason that we cannot do it too.

Randy

Ask and you shall receive.

Here are links for two different DIY CD (capacitive discharge) welders for making or repairing battery packs. The tabs are spot welded 99.9% of the time, some use a threaded stud but they are rare. Soldering generally transfers too much heat to the cell and will kill it before the battery is even in use. They can be soldered but it takes a great deal of care.

http://www.rcgroups.com/forums/showthread.php?t=763308

http://www.ledhacks.com/power/battery_tab_welder.htm

ETA: If you really want to get into the why and how of batteries I'd suggest looking at the forum over at The Endless Sphere.

[wharf rat]

I have a friend that rebuilds battery packs for the local contractors and built his own spot welder. He tells me that most original packs are pretty sub-standard (he recently opened a name-brand pack and the cells were "AA"s, not "C"s although the case was big enough to hold C's--now you know why the big-box discount stores can sell for less). He can build a much better pack for much less than what most original replacement packs cost. He purchases the individual batteries online, btw.

As for the rest of us that don't have the spot welder, my sons and I used to race electric rc cars. We usually bought individual batteries and built our own packs by using braided ribbon and soldering it with a 40w iron. The heat was enough to solder the braid without damaging the cell. I built a ton of packs this way and can't see why it wouldn't work for a tool. I'd be willing to bet that everything is still online (it's been 15 years since we raced).

[Syed]

Hi,jonboy,

Assuming your batteries look like this;

You can hold you batteries between two plastic (or any other suitable material) plates, one at the bottom and other on top. Underneath these plastic plates you can place thin pieces of conductor strips slightly bulging out at contact points. Both plates can be held together with 5-6 screws parallel to the batteries.

[Tom Lathrop]

Ijust bought this pair of 14.4v NIMH Makita batteries for $62. Cheaper than having them rebuilt or buying individual cells and doing it myself. Cheaper than buying from the local Battery source too. Have gone through more batteries and tools than I can count. Its a part of the disposable economy but I see no real way round it. The down side of high power battery packs is that they have more cells and thus, more probability of failure and I'd stay with the 12v kind if that was practical.

Never buy NOL (New old Stock) batteries that have been on the shelf for a long time. They don't last.

http://www.ebay.com/itm/2-14-4V-3000...item1e606e361d

[Stiletto]

Re the spot welding vs soldering. No doubt about it that the manufactured ones are spot welded, but once you get the hang of doing it the way I described you can get the pre-tinned components to take in the split second before the heat is bled away.

That is the reason for a large headed iron, the localised area is heated quickly melting the solder and then removed before any large amount of heat builds up. The total amount of heat applied is minimised.

I have in the past bought batteries that come with spot welded tags attached, but havent come across any in the sizes for cordless tool packs.

Tom, that is a very good deal!

[MN Dave]

I have in the past bought batteries that come with spot welded tags attached, but haven't come across any in the sizes for cordless tool packs.

Try searching on 'sub c-cell' you should find a lot of them.

The comments on this page seem helpful. There are also a number you tube videos showing the process.