BA

Bay Area Dave

24/05/2004 9:23 PM

Ever had a NiMHi battery repaired?

Got an 18V nickel metal hydride Makita battery that shows
the same voltage on all cells but has no power. Obviously,
at least one of the cells must be bad. Ever had any type of
repair facility fix one of these puppies? Makita said to
"throw it out". Thanks a LOT, Makita! I can get 3,000
milliamp C batteries from Radio Shack, but then there is the
issue of identifying the bad cell(s) and soldering the
ends of the new battery into the circuit. Using a
conventional soldering iron gets the battery pretty toasty
(been there; done that before for making up phone battery
packs when no replacement is available). The batteries are
sold in packs of 2 for around $12-15. A new Makita 18 volt
battery is about $70 the last time I checked. found one
on-line for $63 just now...


dave


This topic has 16 replies

Bb

BruceR

in reply to Bay Area Dave on 24/05/2004 9:23 PM

24/05/2004 4:04 PM

Leon wrote:
> Totally different thing here. I was looking at the new B&D 24 volt lawn
> mowers a couple of days ago. The 24 volt battery pack will power the mower
> long enough on 1 charge to do 1/3 acre.
> The replacement cost of the battery was ..... $19.95. Ever think we are
> being raked over the coals for our tool batteries?
>
>

Perhaps 8^)


Could also be that since the lawn mower doesn't need to be as compact as
a cordless handtool, they might use a different type of cell (sealed
lead-acid perhaps).

-Bruce



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BA

Bay Area Dave

in reply to Bay Area Dave on 24/05/2004 9:23 PM

25/05/2004 2:21 AM

I believe you, Michael. I once replaced an obviously bad
nicad in a battery pack with a high amperage one from Radio
Shack and before I knew it another cell failed.

dave

Michael Daly wrote:

> On 24-May-2004, Bay Area Dave <[email protected]> wrote:
>
>
>> I can get 3,000
>>milliamp C batteries from Radio Shack, but then there is the
>> issue of identifying the bad cell(s) and soldering the
>>ends of the new battery into the circuit.
>
>
> You don't want to do that. If the new battery isn't an exact match
> to the old ones in capacity, you'll only toast another battery soon
> (they won't all discharge and recharge at the same rate).
>
> If you are going to replace, replace them all at the same time.
>
> BTW - have you opened the thing? You might find that the batteries
> are smooth on both ends - no bump on the + end. A standard battery
> won't fit if that's the case. You'll have to find equivalent
> "industrial" batteries.
>
> Mike

Lr

"Leon"

in reply to Bay Area Dave on 24/05/2004 9:23 PM

24/05/2004 9:41 PM

If all cells show the same voltage and you can get no power there is a
connection problem IMHO. I know that in my Panasonic battery pack there are
diodes and or resistors. Does you battery pack have these also? Could one
of those be bad? When you say you have no power, do you mean there is no
voltage at the battery terminals or there is voltage but not enough to run
your tool?

Normally a shorted cell will show no voltage. Seems like something in the
pack other than the cells may be bad. Maybe a bad connection.


I have had a family member overhaul my 2 Panasonic batteries at her
electronics business.

MD

"Michael Daly"

in reply to Bay Area Dave on 24/05/2004 9:23 PM

25/05/2004 12:42 AM

On 24-May-2004, Bay Area Dave <[email protected]> wrote:

> I can get 3,000
> milliamp C batteries from Radio Shack, but then there is the
> issue of identifying the bad cell(s) and soldering the
> ends of the new battery into the circuit.

You don't want to do that. If the new battery isn't an exact match
to the old ones in capacity, you'll only toast another battery soon
(they won't all discharge and recharge at the same rate).

If you are going to replace, replace them all at the same time.

BTW - have you opened the thing? You might find that the batteries
are smooth on both ends - no bump on the + end. A standard battery
won't fit if that's the case. You'll have to find equivalent
"industrial" batteries.

Mike

Pj

"P©WÉ®T©©LMAN ²ºº4"

in reply to Bay Area Dave on 24/05/2004 9:23 PM

24/05/2004 7:52 PM


"Leon" <[email protected]> wrote in message
news:[email protected]...
> Totally different thing here. I was looking at the new B&D 24 volt lawn
> mowers a couple of days ago. The 24 volt battery pack will power the
mower
> long enough on 1 charge to do 1/3 acre.
> The replacement cost of the battery was ..... $19.95. Ever think we are
> being raked over the coals for our tool batteries?

Different type of battery altogether though (acid or gel cell probably), but
I do agree cordless tool batteries (at least good quality ones) are way too
expensive these days.

Assorted Bi-Metal Recip blades :
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=4304324181&ssPageName=STRK:MESE:IT
--
© Jon Down ®
http://www.stores.ebay.com/jdpowertoolcanada

En

Eugene

in reply to Bay Area Dave on 24/05/2004 9:23 PM

24/05/2004 9:05 PM

Bay Area Dave wrote:

> Got an 18V nickel metal hydride Makita battery that shows
> the same voltage on all cells but has no power. Obviously,
> at least one of the cells must be bad. Ever had any type of
> repair facility fix one of these puppies? Makita said to
> "throw it out". Thanks a LOT, Makita! I can get 3,000
> milliamp C batteries from Radio Shack, but then there is the
> issue of identifying the bad cell(s) and soldering the
> ends of the new battery into the circuit. Using a
> conventional soldering iron gets the battery pretty toasty
> (been there; done that before for making up phone battery
> packs when no replacement is available). The batteries are
> sold in packs of 2 for around $12-15. A new Makita 18 volt
> battery is about $70 the last time I checked. found one
> on-line for $63 just now...
>
>
> dave
If you have voltage on each cell but not the pack then I would suspect
something else, perhaps the thermal fuse is bad?

Radio shack has the worst batteries, I'd bet the mAH rating on the Makita
pack is much more than the radio shack cells. Also the batteries inside
the Makita pack most likely are not consumer top but the spot welded
connected type.

Search for places like Batteries plus who can rebuild the pack with new
cells if needed, or is you determine the cells to be bad order them from
someone like digikey or mouser who can spot weld them into the right
config.

Lr

"Leon"

in reply to Bay Area Dave on 24/05/2004 9:23 PM

25/05/2004 11:56 AM


"Bay Area Dave" <[email protected]> wrote in message
news:[email protected]...
> Leon, not enough power to cut a 1x1 when used in my 6 1/2"
> circular saw. It spins a little slower than normal and has
> very little power. No load voltage on each cell is normal.
> I don't have a load tester to check them properly.


The cells probably have a surface charge that indicates the normal voltage
and diminishes quickly once a load is applied. Surface charges on charged
batteries normally indicate a voltage greater than the capacity of the
battery or cell.

BA

Bay Area Dave

in reply to Bay Area Dave on 24/05/2004 9:23 PM

25/05/2004 2:23 AM

your little ditty added nothing of value to this thread,
Egotistical TW.

dave

Tom Watson wrote:

> On Mon, 24 May 2004 21:23:04 GMT, Bay Area Dave <[email protected]>
> wrote:
>
> A young man who lacked in capacity
> Sought out help with his lack of ampacity
>
> Had he looked to his shorts
> He'd found help there of sorts
>
> But instead found the rocks of compacity
>
>
> (burma shave)
>
>
>
> Regards,
> Tom.
>
> Thomas J.Watson - Cabinetmaker (ret.)
> tjwatson1ATcomcastDOTnet (real email)
> http://home.comcast.net/~tjwatson1

Pj

"P©WÉ®T©©LMAN ²ºº4"

in reply to Bay Area Dave on 24/05/2004 9:23 PM

24/05/2004 5:56 PM


"Bay Area Dave" <[email protected]> wrote in message
news:[email protected]...
> Got an 18V nickel metal hydride Makita battery that shows
> the same voltage on all cells but has no power. Obviously,
> at least one of the cells must be bad.
> dave

Actually Dave if all cells show the same voltage individually but have no
power combined I would suspect a wiring connection problem, troubleshoot
that first!


--
© Jon Down ®
http://www.stores.ebay.com/jdpowertoolcanada

Lr

"Leon"

in reply to Bay Area Dave on 24/05/2004 9:23 PM

24/05/2004 10:18 PM


"BruceR" <[email protected]> wrote in message
news:[email protected]...
>
> Could also be that since the lawn mower doesn't need to be as compact as
> a cordless handtool, they might use a different type of cell (sealed
> lead-acid perhaps).
>


Good Point... Seems these type batteries do have a gel cells.

BA

Bay Area Dave

in reply to Bay Area Dave on 24/05/2004 9:23 PM

25/05/2004 2:17 AM

Leon, not enough power to cut a 1x1 when used in my 6 1/2"
circular saw. It spins a little slower than normal and has
very little power. No load voltage on each cell is normal.
I don't have a load tester to check them properly.

dave

Leon wrote:
When you say you have no power, do you mean there is no
> voltage at the battery terminals or there is voltage but not enough to run
> your tool?

Wi

"Wilson"

in reply to Bay Area Dave on 24/05/2004 9:23 PM

25/05/2004 3:18 AM

The cell measurement will find a shorted cell. You need to measure each
cell under load.
If you can't get at the cells connected to the motor, use a few feet of 18
ga wire as a load. Just connect it to your meter probes and then measure
across each cell. There are good battery people in the model airplane
magazines. One is SR. You have to clean well and solder quickly. Get
solder tabs if buying new cells.
Wilson
"Bay Area Dave" <[email protected]> wrote in message
news:[email protected]...
> Got an 18V nickel metal hydride Makita battery that shows
> the same voltage on all cells but has no power. Obviously,
> at least one of the cells must be bad. Ever had any type of
> repair facility fix one of these puppies? Makita said to
> "throw it out". Thanks a LOT, Makita! I can get 3,000
> milliamp C batteries from Radio Shack, but then there is the
> issue of identifying the bad cell(s) and soldering the
> ends of the new battery into the circuit. Using a
> conventional soldering iron gets the battery pretty toasty
> (been there; done that before for making up phone battery
> packs when no replacement is available). The batteries are
> sold in packs of 2 for around $12-15. A new Makita 18 volt
> battery is about $70 the last time I checked. found one
> on-line for $63 just now...
>
>
> dave
>

TW

Tom Watson

in reply to Bay Area Dave on 24/05/2004 9:23 PM

24/05/2004 8:51 PM

On Mon, 24 May 2004 21:23:04 GMT, Bay Area Dave <[email protected]>
wrote:

A young man who lacked in capacity
Sought out help with his lack of ampacity

Had he looked to his shorts
He'd found help there of sorts

But instead found the rocks of compacity


(burma shave)



Regards,
Tom.

Thomas J.Watson - Cabinetmaker (ret.)
tjwatson1ATcomcastDOTnet (real email)
http://home.comcast.net/~tjwatson1

BA

Bay Area Dave

in reply to Bay Area Dave on 24/05/2004 9:23 PM

25/05/2004 2:20 AM

yup! which is why I bought replacement batteries for a
bicycle lighting system at Fry's Electronics and the next
time from Interstate Batteries. Paid less than 1/2 price.

dave

Leon wrote:

> Totally different thing here. I was looking at the new B&D 24 volt lawn
> mowers a couple of days ago. The 24 volt battery pack will power the mower
> long enough on 1 charge to do 1/3 acre.
> The replacement cost of the battery was ..... $19.95. Ever think we are
> being raked over the coals for our tool batteries?
>
>

Sk

"Swingman"

in reply to Bay Area Dave on 24/05/2004 9:23 PM

24/05/2004 4:37 PM


"Bay Area Dave" wrote in message
> Got an 18V nickel metal hydride Makita battery that shows
> the same voltage on all cells but has no power.

www.primecell.com

Clunky website, best rebuild service around.


--
www.e-woodshop.net
Last update: 5/15/04

Lr

"Leon"

in reply to Bay Area Dave on 24/05/2004 9:23 PM

24/05/2004 9:45 PM

Totally different thing here. I was looking at the new B&D 24 volt lawn
mowers a couple of days ago. The 24 volt battery pack will power the mower
long enough on 1 charge to do 1/3 acre.
The replacement cost of the battery was ..... $19.95. Ever think we are
being raked over the coals for our tool batteries?


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