cord less drill;

Years ago I bought a Ryobi 14.4 volt cordless drill. It gave good service . when the batterys gave up I bought a new one because it was cheaper then new batterys. This fall the second set of batterys died and I had two good drills and chargers. Harbor Freight had their brand of battery packs on sale for ~ $8. I got two and it was not to bad a job to take out the ni-cad cells and fit them to the Ryobi battery cases. They have worked well with quite a bit of use . I wonder if They use a poorer grade of batterys. All the ni-cad seem to be made in China. I have considered using a resister to drain the battery completely before each charge. Any thoughts? Richard

Reply to
Richard Hanley
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"Richard Hanley" wrote: (clip) I have considered using a resister to drain the battery completely before each charge. Any thoughts? ^^^^^^^^^^^ Since you have two, why not just run until the battery is really low, and then swap to a frewshly charged one? (and, of course, put the discharged one on charge immediately.

Reply to
Leo Lichtman

You don't need to use a resistor , just clamp or tape the trigger down . FWIW I drain the batteries on my cordless stuff at work completely dead before *every* charge . My batteries last on average 3X longer than anyone else in the shop - as soon as their drill slows , they slap the battery in the charger .

Reply to
Terry Coombs

You can kill for ever a Ni Cad by using a resistor. The minimum voltage per cell is something like 1.1v and if below it can reverse and forever kill that link in the battery.

Just use the motor to run them down - e.g. use one down and then switch and get that other one on the charger.

I used to fly RC airplanes and had to have $1M lib insurance. The large issue was bad or non-spec'd batteries. Without batteries - loss of control - and you now have a heavy un-guided flying object looking for a car or house and pray not a person. We went to large extents to do this correctly and were not allowed to use the new fancy designs that are now common.

Martin

Reply to
Martin H. Eastburn

The above is both true and confusing. You can forever kill a NICAD

*battery* by discharging it with a resistor, but it is perfectly OK to discharge an individual NICAD *cell* with a resistor. By "battery", I mean several cells strung together in series.

The problem with purposely discharging a NICAD battery occurs when one of the cells happens to be weaker than the others; in that case, the weaker battery can actually be "reverse charged" as you discharge the pack, which will ruin that particular cell, thus ruining the battery pack.

Even though NICADS have been around for decades, there is still much lore around regarding their care and feeding, much of it promulgated by manufacturers of chargers and conditioners. After having my hands on literally thousands of radio battery packs throughout their lifespan, I can tell you that anything you get over two years of service from a NICAD or NIMH pack is pure luck. Old NICADS can be temporarily resurrected by various methods, but it is not worth your time. Throw them away or rebuild them using new cells, and get on with the rest of your life.

Vaughn

Reply to
Vaughn

A good place to buy NiCad cells and rebuild battery packs yourself is:

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've ordered from them several times with no problems. They also rebuild battery packs.

Steve

Richard Hanley wrote:

Reply to
Steve Smith

Terry, I hear you, but what you say flies in the face of what battery manufacturers tell us. By running Ni-Cad packs completely down that way you risk of applying reverse polarity to the weaker cells, which can ruin them quickly. You're also needlessly adding wear to the tool's bearings, gears and motor brushes.

The "right way" is to use the battery pack until the tool starts to slow down and then recharge it, the way you say the other guys in the shop do it.

The "memory effect" often worried about for Ni-Cad batteries is only germane when the cells are repeatedly just slightly discharged before recharging them. A typical situation of that kind is when they're used in cordless household phones, where the phone is usually set back on the charger after short periods of use, before the batteries are discharged very much.

By the time a cordless tool starts to slow down the Ni-Cads are close enough to completely discharged that memory effects aren't a factor.

If you can point me to a citation which supports your method I'd appreciate seeing it.

Happy New Year,

Jeff

Reply to
Jeff Wisnia

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