12v - 14:4v

Oh use a bit of common sense. Do the items still work?

Erm! No

I see you knocked his URL out. ;-)

I'm talking long term, not short term.

I would expect the charging circuit to limit charge current to a sensible figure. If left charging the "end of charge" circuitry might have a bit of problem determining an end point.

Run both units flat and then re-charge. If they charge up and work then assume both OK

To be honest if I had posted this question my mate would have told me to put both units back in their boxes and return them to the shop. Since he would assume I'm to stupid to own power tools :-)

The 12v pack looks like a flat 14.4v pack so the driver won't care.

The battery probably had to supply less current so it wont care either.

I expect the driver and battery to be keyed to prevent putting a 14.4V pack in a 12V driver.

Hi Robert

The charger will accept either 12 or 14:4v batteries & charge them accordingly. Its the fact that the 12v battery was used in the 14:4v driver that oncerns me.

What do you mean 'both units'? How would I run a 14:4v driver without a battery 'flat'? How would I charge up a bare 14:4v unit oh wise one?

I suggest you learn to read posts properly before you respond with sarcastic replies f****it.

Thanks Dennis. Thats what I wanted to know. Makes sense.

Indeed they are, the 14:4v is too big to go into the 12v, but not t'other way around.

As another poster pointed out, but perhaps it needs more emphasis, the damaging/dangerous thing to do is put a higher voltage battery in a lower voltage tool - and that Makita are probably keyed to prevent that. They didn't key it the other way (low voltage battery in high voltage tool) because it's harmless.

If it fitted one way round It would be reasonable to assume the manufacture realised that some prat at some time would try it! and really it's not some chinese crap.... The fact they both use the same charger means the connections are basically the same and the intelligent charger will sense which battery and charge accordingly. The 12V battery would work but not deliver the full capability of the tool. and also as the 14.4V battery loses its charge it will be running at 12v and lower. So don't worry and if in a couple of years time when the screwdriver expires you can always blame it on the day the wrong battery was fitted! Des

I hope he did a risk assessment...

There's probably no difference at all between the motors in the 12v and 14·4v machines, so no, I shouldn't imagine any damage at all. It's really all marketing hype, innit.

If you're talking about, say, a 14·4v battery driving a, say, 7·2v drill there may have been an emission of the magic smoke within a few moments, otherwise no long-term harm.

Undervoltage, such as you imply, is just the same as a flat(tish) battery.

Realistically, if Makita is a responsible manufacturer, any harmful combination of battery/drill should be physically impossible (or difficult).

You're not thinking of sueing John, are you? :-)

Don't be silly....Daves middle name is John. ;-)

Peter actually. Dearly loved rock - that's me.

No, in fact, it wouldn't.

Fast nickel chargers do not sense *absolute* voltage at all. They charge at constant current (more or less) and detect a voltage DROP to terminate the fast charge regime.

The only problem I can see is that a 12v charger might not have enough voltage to charge a 14.4v pack.

Just will run it a bit slower, that's all.

With Makita it depends on the charger. I have about 5 different ones that came with different tools at different times. The chargers that come with the higher range tools tend to be able to charge older battery types and that includes lower voltages where needed - so one of the 14.4 chargers I have will do 9.6, 12 and 14.4v

Unless you worked the driver really hard, the other way round would probably not have done much harm either, although the potential (ahem...) was there.