A new one on me

I purchased 3 3000 ma-hr 18v Ni-Mh batteries off ebay. You can't rebuild an old battery for $31. I've always had very good luck with them, they out last and out preform Ni-Cds and Li-ions, (Unlike Guido, I don't care to take my batteries apart, short out each cell and them charge them at a controlled rate. I use them, then I charge them. My time is too valuable to play with them.)

Well I charged all the new batteries, only took less than 5 minutes each. Usually a dead battery takes about 20-30 minutes to charge with the recommended dewalt charger. Then I decided to load test them using a dewalt circular saw. I used a green treated 4x4, new dewalt blade and had the blade depth at max, 2.25 inches. Each battery made one pass through the 4x4 and on the second pass pooped out. That's about all my dewalt Li-ion can do. I put the new batteries back on the charger. Again only about 5 minutes or less and they were charged. Put them back in saw and made pile of sawdust. It was like they need a wake up call or something. I have 6 other Ni-Mh batteries, oldest is 7 and they work great.

I bought two of these new batteries to give to my son and SIL as birthday presents. Last Christmas I gave each a dewalt 2 pk, drill, 1/4 inch impact, 2 li-ion batteries and the charger they will need for the NI-Mh batteries. Now they will have a good heavy duty battery in case Santa brings them more dewalt tools.

I've never seen a new battery act like this, have you?

Hello Geo-TH In,

Yeah! I have. New pack should not be charged at abnormal rate. It only takes one battery to spike up the voltage, that fooled the charger. Short charging equals short life as you found out. That is why I charge a new pack, even if it is old cells, at a slow rate. That way all the cells come up even. By the way a pack will increase in capacity as it gets cycled, for the same reason it charges up full when slow charged. The nature of the beast. You should discharge you new of Ni-Mh fully before charging.........


Guido.

Okay, you guys know a lot more about this stuff than I ever will. I recently repaired (shined up the contacts) 3 old 7.2 and 9.6 volt Makita drills and jig saw I've had for a couple decades. Some of the batteries I thought were garbage are in fact good now that I can run them. Some are not good at all. So, my question is on charging. I have the standard Makita multiple voltage (7.2-12v) charger. As far as I know it only does the standard old style batts, whatever they are made of. Is there a better option that will work better with these and my Porter Cable or other rechargeable batts? Is there a website that outlines this stuff in language an idiot like me can comprehend?

2nd question- who among us is going to become a zillion-aire by designing an adapter that allows different styles of batteries to be used on any brand of tool?

You are lucky to have old school battery,
Ni Cd last for decades. Early cell phone
used them. I never got more than about 18
months out of battery, about 500 charges. I
like Ni Mh, Toyota uses them in prius. They
are designed for fast charge and discharge.
Some hybrids are experimenting with Li
ions. I haven't had good luck with them. So
far The dewalt ions don't have a large out
put. They are the most expensive. I find I
get the biggest ban for the buck with Ni
metals.They have outlasted and out
preformed the others. If you can come with
a universal adapter for battery you might
get rich. About 15 years ago I purchased an
18v dewalt halve inch drill. Then I made
the decision to go strictly with one
battery, 18v dewalt. I buy bare tools
without battery. BTW, dewalt makes the
charger for Ni Mh, but no battery. So I go
to eBay and buy Chinese battery. I was
told, dewalt tools are also made in China.

Hello Geo-TH,In

There are many multi chargers out there. Here is mine. It will charge 3 types of Lithium batteries. NIMh. NiCad's and lead acid. It is a 30volts 5 amp charger. It has many charging cycles including fast, re peak, and auto.
A few other functions as well. You can see on the picture some of them. Charge rate, pack voltage, charge taken in MA, and time. I would call this a universal charger. Just clip it on, select battery type and charge rate, it does the rest
Guido.

Guido, looks like you like to take batteries apart and solder in new cells. For me, life is too short. I buy the $31 batteries, put them in dewalts charger that shuts off when battery is charged. Unlike the old dewalt chargers for the Ni cds, they never shut off and cooked the battery. I use the batteries for years with no fuss. My batteries last so long, I keep old batteries as parts to repair the case and the end that goes in the tool. One time I need a part for the case and had to use velcro to hold battery in tool that I keep in the shop. Geo