Makita BHP453 drill repairs.

[George94]

Being a nitwit, I dropped my expensive Makita in the river. It took a week before I was able to move the boat and then dive down and fish it out.

 

The drill itself was full of shrimps when i finally desubmerged it (Athy probably knows a better word for this). But, taken apart and deshrimped and demudded (Athy probably knows a better word for this), it appears to be in good nick.

 

Except, that is, for the Lithium battery, which seems to be dead as a door-nail. Are these things revivable? The charger doesn't recognise it, but being an "intelligent" charger, I think it likes to see a little power in the battery, and if it doesn't, it can't be bothered to get out of bed and switch itself on.

 

Two questions for the experts in drills and battery revival. First, what grease should I use for the drill when I reassemble it, and second, is it worth running some 12V into the battery to see if it will bring it back to life?

 

And if there is no confidence in the possibility of resurrecting the battery, is there a source of CHEAP replacements?

 

Nope? I feared as much.

Edited August 19, 2013 by George94

[stagedamager]

A call to makita may help but AIUI once a li ion battery is drowned it isnt salvageable im afraid.

Well done for finding it, mines still down there somewhere! !

Dan

[George94]

A call to makita may help but AIUI once a li ion battery is drowned it isnt salvageable im afraid.

Well done for finding it, mines still down there somewhere! !

Dan

 

Well, if that's the case, I might take it apart and bung in some Eneloops. I don't suppose the drill will mind. Volts are volts.

[Nickhlx]

I would suggest waterproof grease

 

( sorry I couldn't resist )

 

If you are in to soldering and the battery is screwed together, you might find cells on EBay - they would need to be of the same type though.

 

Alternatively you could try applying the correct voltage ( current limited) to each cell for a few minutes to kick start them, then put the pack back into the charger for it to complete.

 

Depending on the cells, they would need approx 4.0 volts per cell and limited to say C/3. This is just to bring up the pack voltage to around 3.0 volts per cell, so that the charger can then recognise and carry on charging them

 

From Wiki :

 

 

Charging procedure[edit source | editbeta]

The charging procedures for single Li-ion cells, and complete Li-ion batteries, are slightly different.

• A single Li-ion cell is charged in 2 stages:^[33]

1. CC
2. CV

• A Li-ion battery (a set of Li-ion cells in series) is charged in 3 stages:^[48]

1. CC
2. Balance (not required once a battery is balanced)
3. CV

CC: Apply charging current to the battery, until the voltage limit per cell is reached.

Balance: Reduce the charging current (or cycle the charging on and off to reduce the average current) while the state of charge of individual cells is brought to the same level by a balancing circuit, until the battery is balanced. Some fast chargers skip this stage.

CV: Apply a voltage equal to the maximum cell voltage times the number of cells in series to the battery, as the current gradually declines asymptotically towards 0, until the current is below a set threshold of about 3% of initial constant charge current.

Periodic topping charge about once per 500 hours. Top charging is recommended to be initiated when voltage goes below 4.05 V/cell.

Lithium-ion is charged at approximately 4.2 ± 0.05 V/cell except for "military long life" that uses 3.92 V to extend battery life. Most protection circuits cut off if voltage greater than 4.3 V or temperature greater than 90 °C is reached. Below 2.50 V/cell the battery protection circuit may render the battery unchargeable with regular charging equipment. Most battery circuits stop at 2.7–3.0 V/cell.

Failure to follow current and voltage limitations can result in an explosion.^[49]

^{If in doubt, don't .... lithium batteries let go in an unfriendly manner}

 

Nick

[George94]

Thanks, Nick.

 

Hmm. Sounds like a job for an expert with expensive equipment.

 

I might try connecting another 18V battery to it and see what happens.

 

And will stand well clear!

[RLWP]

 

Depending on the cells, they would need approx 4.0 volts per cell and limited to say C/3. This is just to bring up the pack voltage to around 3.0 volts per cell, so that the charger can then recognise and carry on charging them

 

 

Nick

 

Could this be as simple as three AA batteries, Nick?

 

Richard

[Bod]

Google "recell your battery"

There are places that will repair the battery, to as new.

Not cheap but better than buying new!

 

Bod

[Barry]

Google "recell your battery"

There are places that will repair the battery, to as new.

Not cheap but better than buying new!

 

Bod

 

Interesting! I have a dead DeWalt battery pack - Found one on on Amazon. Its only thirty quid plus delivery. Better than the last one I bought

[smileypete]

Could have suffered electrolysis right up to and including the power switch

 

Still the bare drills aren't toooo dear these days, and try Ebay for cheap batt replacements too.

 

You probably know this all too well by now, but with cordless tools on botes its good to use a lanyard, eg firmly tie wrap a carbine hook to the handle then use a bit of wire with a loop at each end to tie it off to an handrail say with another carbine hook.

 

cheers, Pete.

~smpt~

Edited August 25, 2013 by smileypete

[onionbargee]

What ever you do, do not mess with the gearbox, or you will enter a world of hundreds of parts that never go back wherever they came from.

[George94]

Could have suffered electrolysis right up to and including the power switch

 

Still the bare drills aren't toooo dear these days, and try Ebay for cheap batt replacements too.

 

You probably know this all too well by now, but with cordless tools on botes its good to use a lanyard, eg firmly tie wrap a carbine hook to the handle then use a bit of wire with a loop at each end to tie it off to an handrail say with another carbine hook.

 

cheers, Pete.

~smpt~

 

Indeed. I am reminded of the saying that experience is something you get just after you need it.

What ever you do, do not mess with the gearbox, or you will enter a world of hundreds of parts that never go back wherever they came from.

 

Actually, I had to mess with the gearbox because it was full not just of water and grit, but also many tiny prawns.

 

Amazingly, it's back together, although I am a little unsure of two short rods, about 8mm long. I think they go into an object that looks a bit like a four-leaved clover,and which connects the drive from the gearbox to the chuck. A similar but much larger part connects the injector pump to the drive shaft on the JP3.

 

Tomorrow night I will try it out with a friend's battery.

[onionbargee]

I had to strip down a Makita battery drill, it makes a swiss watch look like meccano. Never again !

[Captain Fizz]

I dropped mine off a scaffold tower, it rattles if you shake it but still works ok.........so I don't shake it!

[bizzard]

That must be the MM, Makita Maraca model.

[George94]

Well, I am delighted (and more than a little surprised) to report that the Makita diving drill is working just fine. Except that the low speed doesn't work, and nor does the selector switch (driver, drill, hammer). I feel that these are minor issues, which I will sort out in due course.

 

It was worth that dip in the muddy old Thames.

 

BTW, I did say drill. The battery is still kaput, but I am working on it. Thanks for the suggestions. I shall let you know how I get on.

Edited August 27, 2013 by George94