18v cordless drill issues

[Sam_i_am]

My cordless hand drill uses an 18v battery. I have two of these batteries to alternate use, and a charger to keep them charged. Both batteries are totally dead and will not charge. The charger is producing 41 volts ... obviously much higher than its suppose to be.

How can both batteries be dead (0 voltage) and what would make the charger put out 41 volts?

 

[RTM]

oth batteries are totally dead and will not charge. The charger is producing 41 volts ... obviously much higher than its suppose to be.

How can both batteries be dead (0 voltage) and what would make the charger put out 41 volts?

Fried electronics in the batteries from over voltage? They May still have a charge in the cells, but the smartness on board won’t let it out?

Guessing here.

 

[Rinspeed]

What brand charger is it.

 

[Sam_i_am]

Bosch

 

[Sam_i_am]

I was able to jump the 2 bosch batteries into a state of positive voltage. Both will power the drill to a degree. I won't be leaving the batteries on the charger at all. So maybe the batteries can be saved, but this charger is not right.

Any one knowledgeable as to what would make this charger put out 41.?? volts when it is supposed to be rated at 7.5v to 24v?

Can it be fixed?

 

[niget2002]

How are you measuring the voltage on the charger? Is a battery hooked up while you're measuring it? If not, it could be the charger trying to 'jump start' a dead battery by overvolting it because it's reading your meter as a 0 volt battery.

 

[The Cobbler]

Lithium? I'll try to remember to measure mine without a battery and see what I get

 

[Rinspeed]

Can it be fixed?

It can be fixed but why bother, I'm sure there's several on Ebay for $20-30.

 

[Sam_i_am]

Lithium? I'll try to remember to measure mine without a battery and see what I get

Yes, lithium.

 

[Sam_i_am]

How are you measuring the voltage on the charger? Is a battery hooked up while you're measuring it? If not, it could be the charger trying to 'jump start' a dead battery by overvolting it because it's reading your meter as a 0 volt battery.

Yes, with the batteries NOT charging. Because of the charger and battery design it does allow testing while the battery is mounted to the charger station.

I will rig up something to simulate.

 

[niget2002]

Yes, lithium.

Lithium could have a BMS that handles the charging built in to the battery and the charger just provides a high voltage low amperage output for the BMS to use.

 

[Sam_i_am]

Yes, with the batteries NOT charging. Because of the charger and battery design it does allow testing while the battery is mounted to the charger station.

I will rig up something to simulate.

edit: Because of the charger and battery design it does - NOT - allow testing while the battery is mounted to the charger station.

 

[The Cobbler]

I remembered to measure the voltage on my charger . without a load the charger measures 8.3 volts

I'll try to remember to measure mine without a battery and see what I get

 

[Sam_i_am]

Thank you for doing that Cobbler, I really appreciate it. I haven't heard much more about this (Bosch) charging sytem.

The one I have seems to be over charging and yours appears to be under charging. Weird!

 

[American Locomotive]

The voltage without a battery connected is irrelevant.

I'm not saying your charger is working correctly, just that modern lithium chargers are not simple transformers.

 

[Sam_i_am]

Roger that American Locomotive. I understand the complex circuitry that some chargers may contain within them. And to that end, charging devices may not indicate true values when not in use. I am only hoping to findf a common denominator for the Bosch BC130 battery charger in its "plugged in" non charging state.

Since the 18v drill is still in working order I'll either need a new charger, a new battery or both to put it back in service.

Nutshell: hoping these chargers have a factory set "plugged in" but "not in use" voltage to determine if my charger is with in specs.

Thank you for the comment, appreciate it!

 

[The Cobbler]

yours appears to be under charging

The voltage without a battery connected is irrelevant.

I think mine is working fine, batteries last & come out fully charged . I suspect it's a sleep voltage & bumps up when a battery is inserted.

 

[AEAdam]

I have Bosch cordless tools. Just note there are multiple 18V batteries like the (newer) CORE batteries. They cannot be charged with the old fast chargers. Just make sure your batteries are compatible with your chargers.

And FWIW, I've had my Bosch 18V for probably 10yrs and all my batteries still run great. I use them every weekend. Stored in an unheated space.

 

[The Cobbler]

Just note there are multiple 18V batteries like the (newer) CORE batteries. They cannot be charged with the old fast chargers. Just make sure your batteries are compatible with your chargers.

but if they're not compatible, so they still fit?

 

[Sam_i_am]

AE, they are NOT compatible in any way.

 

[Sam_i_am]

Anyone who has owned one of these drills knows why I wish to continue its use. I've ordered a charger and battery set.

Hopefully I'll end up with 4 batteries or 2 chargers ..... we shall see!

 

[The Cobbler]

Anyone who has owned one of these drills knows why I wish to continue its use

I have used Bosch for 25plus years . about 3 yrs ago & upgraded to the LIthium , I had 12 volt nicad before that & I have no complaints

 

[AEAdam]

but if they're not compatible, so they still fit?

Yes. Compatible. Fit the tools, fit the battery charger, but will not charge.

The Bosch CORE Batteries, which are very nice, don’t charge on the old rapid charger. They will charge on the original smaller slow charger.

 

[Sam_i_am]

NI-Cd vs Ni-Mh