Sawsall batteries

Digi-Key is generally a good source of quality cells, but you'll have to do the pack rebuilding yourself.

I don't see lithium available but these guys rebuilt all my drill and saw battery packs faster, better and for less money than I could do it myself:

(Your NiCD rebuilds go for $64 each.)

They are happy to answer questions: snipped-for-privacy@primecell.com

No connection other than as an ecstatic customer.

--Winston

I only have about seven names in my filter, and the difference is dramatic! :-)

If they're individual cells, and they're NiCd, (nickel-cadmium), it _might_ help if you gave them a deep discharge through maybe a 1K resistor in series with a 1N4004 diode (forward-biased, of course), and then give them a good charge. You'd probably have to set aside a weekend, because you'd want to let them discharge to about .6 ~ .7V, (the diode forward voltage), or the voltage across the resistor is too low to measure (just two ways of determining the same thing); this could take all night, and you'd have to set aside the next day to charge them REAL GOOD. :-)

Like I say, it _might_ help, and it might not, but it's a lot cheaper to try it than just going ahead and throwing them away and buying a whole new set. :-)

Cheers! Rich

Depends, I guess. What's coming for my old 12V drill is a jumper cable adapter and a car battery (deep cycle would be better, spare car battery is what I have handy.) I'll get something else for when it "really needs to be cordless" but a lot of the time a short cord would be no problem, and it's reaching the end of being worth buying it new battery packs.

If you can put a good 24V lead-acid setup in a wheelbarrow, hand-cart, wagon, tractor-basket or golf cart (ie, fill in appropriate sort of mobility depending what you already use to get around the orchard) and throw 25-50 feet of leads on it plugged into the sawzall, it would beat the crap out of any small pack you can buy or make, and not cost much either. ie, your units you can't remember are likely milli-Amp-hours, so you have 3 amp-hour batteries, if they are going the full distance. One of the best-bang-for-buck golf cart batteries runs 200 amp-hours (@ 6 volts, so you'll need 4 of them) - so if you can put up with a cord, you get 66 times the use and only one battery to charge. Now, those are 62 lbs each, so you can see you'd need something to haul 4 of them around with, but you could also go smaller (ie, 12V 55 ah -you'd only need 2- @42.5 lbs each) and still beat the heck out of little packs. Or you could put a couple of 9 lb 12V 12AH in a backpack....

Doesn't work if you can't have any cord.

I put 1 name in my filter and my experience is f'n great now.

Pretty sure i went NiMH last itme. I see they do it for $98. That's about $30 less that the local place from last time. Still, its $600 to redo the lot and this is year two.

These places tell you NiMH is better than NiCD, guess I take their word for it.

I would like to hear from somebody with the lithium. Will I get a huge increase in service life?

Karl

If you're going to have 50 feet of cable at 24V driving a heavy-duty sawzall (remember, he doesn't want 18V), that's gonna be some hefty cable. Fifty feet (100 foot round trip) of 10 awg will drop about a volt at ten amps.

While you're looking at this, consider switching to NiMH. You can use the same charger as for NiCd and get way better performance. Last time I went through this, I found NiMH packs on ebay for my Bosch far cheaper than replacement cells from Digikey (or anywhere else).

The lithium packs that I'm familiar with (laptop, misc) are complicated.. and some types are potentially hazardous as far as overheating, but then almost any energy storage device is hazardous when mishandled.

Some good brands of NIMH cells with tabs are, IMO, good replacements for building battery packs for portable equipment, and although the technical aspects of charging differ between NICD and NIMH, the NICD chargers could also charge NIMH packs well.. if the charger a moderate-charging-rate delta peak sensing type (not a fast/high-rate/timer type charger).

When comparing cheap grades of different cell technologies, all bets are off, there's no point. Better grades of cells are in a separate class. The best quality/grades of cells have typically been from Japan. There are a lot of different specific cell characteristics for different grades of cells.. info from Sanyo or Panasonic give very good descriptions of their different grades.

Some sources state that NICD are better for cordless tool requirements of intermittent, moderately high drain, power. The equivalent cell size of a NIMH will provide considerably more Ah capacity, which can be a significant benefit for many applications (not primarily cordless tools).

When considering replacement of cells in older packs, one should also be considering upgrading to newer charging units. The old charger is likely to be out-of-spec and/or possibly near failure. I don't test/check out new chargers or cells unattended.. just the same habit as when charging LA lead-acid batteries.

For many of the HSMs here, replacing/bypassing the board of an existing charger probably isn't too complex, for reusing the old charger case receptacle for the existing OEM battery packs.

Some cordless power tool packs contain internal temperature protection circuits or other safety devices which shouldn't be ignored.

I've been using some universal Powerizer NIMH-NICD chargers for over a year with very good results. These are 2-wire chargers, although one or more models come with a temperature sensing lead to prevent battery pack overheating. There are some models that are AC line voltage input only, or DC input (auto/truck lighter socket cord, or AC adapter input).

Some of the MRC brand chargers have a wide variety of selectable features for different cell types and capacities.. generally limited to up to 12V maximum pack voltage, as they come supplied with 12V inputs for portable/mobile use (can also be used with 12VDC AC adapters).

I just found out they make lithium and higher voltage:

Not cheap tho.

Anybody out there swear by or at these?

If it drew 10 amps, he'd get less than 20 minutes to a 3-ah battery - possible, I suppose, but kinda short run-time. Actual length needed depends on size of trees and how bad the terrain is. I don't regard

10AWG as remotely heavy (2/0 is heavy, and 500 mcm is f-n obnoxious) - but two strands of 6 or 8 will take quite a few feet to even add up to the weight of the battery you won't have to pick up in this arrangement unless going for the small back-pack option, which has short wires. And it's far cheaper (battery, wire and charger) than the $600 small-pack rebuild. If the terrain is not friendly to park near the trees, a heavier cable could be brought to the bottom of the tree and a lighter cable to the saw from there, if voltage drop even became an issue. A 1.2-volt drop (10awg) may not be that big of a deal, depending on the saw's behavior - 6 awg would bring it down to half a volt at 50 (100 r.t.) feet.

I don't know what Karl is doing with his trees - some of the "modern" orchards around here would be all set with 15 feet of cord as they are sticking with small (dwarf) trees and less ladder work. Of course, they also have to support the trees so the brittle dwarf stock does not snap in the wind. The older orchards would need longer cords as they still have big trees.

You can buy a small chain saw for $125. They are even designed for cutting tree branches.

-jim

Yep. I got a Stihl 009. Very nice pro quality arborist saw. Nobody but me runs it. You can't beat the sawsall for a neat clean cut next to something you want to keep. And, I let anybody use a sawsall.

cords aren't the answer. Just today we drug 200' of air hose out over the snow to run the shears. REALLY looking forward to the snow melting. You get twice the work done for half the effort. I had to rest this morning after getting hoses in place before I even started. Just finished our 150 trees for today. Only 3000 left.

Karl

I'll never buy another NiMH battery. I once threw away about $50.00 on NiMHs and a "smart" charger, and after what seemed like only a few usages, they wouldn't hold a charge.

Including the pain in the ass factor, it's easier on me to simply buy alkalines. They have a shelf life that's measurable in years, and they seem to last for freaking ever.

I don't know what chemistry my cell phone battery uses (Samsung TracFone, battery part #AB463446BA, 800 mAh, about 2" L x 1 3/8 W x 3/16 thick), but it hasn't disappointed me yet. :-)

Good Luck! Rich

Of, if you're not afraid of investing a little elbow grease, you can get a nice handsaw for about twenty bucks. ;-)

Cheers! Rich

Isn't it spelled "sawzall?"

Thanks, Rich

If that charger charges your NiMH in less than 10 hours, it is killing them.

Wes

-- "Additionally as a security officer, I carry a gun to protect government officials but my life isn't worth protecting at home in their eyes." Dick Anthony Heller

The charger touted itself as a "smart" charger, and came packaged with

4x AA cells; I just ass-u-me-d that the charger would be suitable to use with the cells it came packaged with.

Silly me.

Thanks, Rich