My free drill

[r_chez_08]

Hey,
Today I was at my saturday job, and the bloke I work for offered me his old drill. He said the batteries didn't hold their charge or the charger was .
He wasn't going to spend £80 on 2 new batteries or £50 on a new charger (fair enough) or spend time troubleshooting as his time is worth more than mine, so he bought himself a new dewalt drill with one Li-ion battery for £90.

So Now I have this erbauer drill which retails for around £80. I have used it a couple of times when working for him and its quite a sturdy drill, and has a full metal chuck.

Anyway, enough of that.
The charger, when plugged into a wall, comes up with the fully charged light straight away. I don't know if it is meant to do this, but it doesn't make any odds if a battery is inserted or not.

A new charger on ebay is probably around £15. Worth spending if that is the issue. But is there any way to test the charger?

If both of the batteries have lost their charge then I will replace the cells. It would cost between £15 and 25 per battery, depending on the capacity. I can upgrade them to 3.4ah instead of the stock 1.7ah

Any idea how to test the charger before I start faffing with the batteries.
Cheers
Rob

 

[Nodroz]

Try to see if there's any voltage on the charger?

 

[r_chez_08]

Argh, my dad just took the multimeter down to the boat, I have a cheap one at home but it doesn't seem to give a correct reading
There are 3 pins on the charger, and I dunno which does what.

 

[exenos]

There's only 6 combinations of pins so just guess, you cant hurt anything with this low of voltage.

 

[Doc Sprocket]

There's only 6 combinations of pins so just guess, you cant hurt anything with this low of voltage.

Are you quite sure of that? As I am fairly sure that some cordless tool chargers use a substantially higher charge voltage...

 

[augidog]

wouldn't that be "substantially higher amperage" ?

i believe the light's simply wired to indicate no current is being produced, and not actual state of charge. with a full time light, i'd bet the charger's toast. a battery has to be pretty bad if it won't accept any charge at all, usually a bad one just won't hold the charge.

set to 20V DC, i think your meter will be fine for testing.

corrections welcome, or you can just make fun of me for not knowing, i don't mind.

 

[r_chez_08]

Yeah thats what I thought augidog.
The volt meter seems damaged in some way. I tried testing some 'AA' batteries and they read like .1v or something, when they were brand new, so the meter is crap. It was like £5 anyway.

I think I will get a new charger. I can always return it, and there is one that looks identical to my one on ebay for £15 BIN, BNIB.
I will ring the retailers tomorrow to check to see if the ebay charger part no. will work with my batteries. There seems to be only one charger fs that looks the same as mine so I hope it is the same.

If the charger is the only problem, then for £15 I am happy! My dad has a cordless dewalt which I use, but there is only one good battery for that now, and even that one doesn't hold its charge very well, and the battery is rarely charged up! A half decent drill/driver is useful.

 

[porsche930dude]

if the batteries dont take a charge there is a few tricks you can do to revive them. One way is to shock them with a mig welder. just touch the terminals positive and negative back and forth back and forth a dozen times or so and they will usually take a charge after that.

 

[Doc Sprocket]

if the batteries dont take a charge there is a few tricks you can do to revive them. One way is to shock them with a mig welder. just touch the terminals positive and negative back and forth back and forth a dozen times or so and they will usually take a charge after that.

Interesting! Does this trick work on lead/acid (car) batteries?

 

[Doc Sprocket]

wouldn't that be "substantially higher amperage" ?

Not according to what I have read. My DeWalt 18v battery charger bears the warning label "Danger: High Voltage may be present at the terminals". In addition, I have purchased a few cheap power inverters (12vdc-125vac) that warn against using them with chargers for cordless tools that employ "high voltage". I'm just going off what I have read, however- Some of the cheaper, crappier cordless tools I've had, have a visible step-down transformer feeding the charger, whereas the "good" chargers do not. They may be internal, but the warnings make me wonder.

 

[porsche930dude]

Interesting! Does this trick work on lead/acid (car) batteries?

im not sure but i definatly wouldnt try it without researching it more. you definatly dont wanna be around one that blows up

 

[augidog]

Not according to what I have read. My DeWalt 18v battery charger bears the warning label "Danger: High Voltage may be present at the terminals". In addition, I have purchased a few cheap power inverters (12vdc-125vac) that warn against using them with chargers for cordless tools that employ "high voltage". I'm just going off what I have read, however- Some of the cheaper, crappier cordless tools I've had, have a visible step-down transformer feeding the charger, whereas the "good" chargers do not. They may be internal, but the warnings make me wonder.

lol, i think it would have been better if you'd just made fun of me for not knowing...because now i have no idea what i know :rolleyes3:

i think i'll just watch and see how this works out.

but one thing i'm sure of...no way i let an active welder get that close to a lead-acid battery.

 

[crazyman]

According to a site that I once visited, it said most modern tool battery chargers send substantially higher voltage in timed bursts. Say 15 seconds on, 1 minute off, repeat.

I cannot recall the site. I wander the net endlessly. If I don't save it somehow, I lose the verbage that I found it with and/or the link.

 

[r_chez_08]

if the batteries dont take a charge there is a few tricks you can do to revive them. One way is to shock them with a mig welder. just touch the terminals positive and negative back and forth back and forth a dozen times or so and they will usually take a charge after that.

I heard something similar with shocking them with AC voltage.
Apparently over time, batteries build up crystals, and the sudden voltage/ current breaks up the crystals.

I am taking physics A level, and so I might ask to borrow a multimeter, or speak to the technitian about it to see if he has any idea (I am sure he would love to talk )

 

[porsche930dude]

yup they get sulferized. you can also desulferize a battery
http://www.diygokarts.com/vb/showthread.php?t=2276

 

[r_chez_08]

Fixed my multemeter (bad fuse)
Batteries read 13.4v and 13.7v. They should read 14.4v.
However, I know the batteries are low on V, the drill is slow!

I tested all the pins on the charger. I got .15v from one combination, but that's it.
I think the charger is dead. It has security screws, so I will check my screwdriver set to see if I have the correct bit.

 

[augidog]

good info on sla maintenance here, mucho appreciado.

so it looks like two good batteries just waiting for a good charger, meaning you made out pretty good too.

 

[r_chez_08]

I think so. Forgot to get the screwdriver bit, may be able to fix the charger or modify it.

 

[Doc Sprocket]

Check the basics first. The company I used to work for went through a rash of Milwaukee chargers. Turned out to be blown internal fuses.

 

[r_chez_08]

Thanks, yeah I will check voltage to see where it is lost. Pretty sure it should read atleast 14v, unless the battery has a way to tell the charger to start charging?