I have the 2 speed 19.2v h freight drill. I does have the thermal switch and it didnt matter as the freaking charger fried the battery anyway. I took the pack apart (1.3 amp/hr cells BTW- very poor performers) Put some more cells in place from some surplus packs I'd bought when the price looked right and am still using the drill today. The dewalt pack (18 v drill) that I rebuilt for a bud used a temp sensor as well. They were 2.6 amp/hr cells in the dead pack that I replaced with 1.7 amp/hr (that I already had) cells and the dewalt charger didn't kill them. Charged em up and shut down without overheating the pack. I've read of guys using the dewalt charger from their
18v drills could be used as a universal charger as they apparently have some sophisticated intelligent charging capability. I believe it was the dw 9116 charger (like 7.2-18 v) . I seem to recall the one proviso of opening the
9116 charger to allow one to get at the contacts for the charger- careful as the contacts apparently can give you a 110v shock. Pat
There was a DeWalt charger model that was recalled because of a shock hazard. It seems that the one of battery terminals was hot to earth ground, and could deliver a potentially fatal path from the AC line supply to ground.
I don't remember the specific DeWalt model, but the recalls weren't difficult to find, when I was looking up the model number.. I'd bought one at a flea market several years ago, just because it was included in a box of stuff I wanted.
I assume that many newer chargers could produce similar shock hazards, as the newer designs (could include many China products) are designed and built to meet a cost limit, and may not include any proper isolation from the AC power cord voltage.
Randomly experimenting/improvising charging setups could be dangerous if someone is thinking "it's only 7 to 20 volts, that can't hurt me".
One should always investigate or test the supply's output before deciding to ignore any proper electrical safety precautions.
Save your equipment and components (and possibly your eyes and skin), always use a fuse. It's not difficult or costly to fabricate some fully insulated test leads that include fuse holders.
Welll....is it the sort of charger that has a plug back going to the charger module? - or is it one unit that plugs into the mains? - if its a plug pack type, check the output of the plug pack, if its low, then replace.....if its inside the charger box, open it up, have a look....might be obviously something wrong.....
Other people are quite right - you get what you pay for - cheap drills have cheap chargers which stuff batteries fairly rapidly, especially if left on for extended periods. The $5 mains plug timer is a good idea for these things, set it for X hours of run time, no more cooked batteries...
DEWALT make truly EXCELLENT drills, but then they are typically 5-10 times the price of the Chinese Cheapies...you get what you pay for....the archillies(sp) heel of the Chinese ones is the low grade batteries used, combined with repeated overcharging/cooking... you Can rebuild the packs, but it will cost more than a new drill....as noted here, collect enough dead ones, select good cells, rebuild anyway. Doesn't make economic sense, but then neither does fitting and machining as a hobby....
Many uses for the motors from dead drills , especially the ones with the variable slipping clutches..- the robo wars people use them as drive motors, seen one used as a power feed on a mini-mill, can be adapted to antenna rotators....any more ideas people, I got a few of em stashed away....too good to throw out...
That doesn't follow. The reading on a meter is an average, but the battery can charge on peaks at 25V even if the average voltage is less. Look at battery terminal voltage with battery-out-of- charger, then with battery-in-charger, and if the second is higher, it IS charging.
If the charger isn't charging either battery, it has likely got a blown component, possibly the main current-sense resistor. Can you disassemble the charger? I've seen dead chargers where the replacement of that resistor and an amplifier chip (the current-sense voltage went wild and blew the amp when the resistor opened up) fixed it completely.