Forums

Power tool battery charge

Started by Sylvia Else December 8, 2018
This charger claimed that both my batteries are faulty, which seemed a 
but of a coincidence, so I suspected the charger instead.

Here's a picture of the board:

https://www.dropbox.com/s/saeqrsralcdsc54/chargeBoard.jpg?dl=0

I'm puzzled by the largish round holes, both in the middle of the board, 
and diagonally towards the left, in the proximity of the labels for C13 
and R43. In both cases, they're where I might have expected to find 
anti-tracking slots, but holes are not going to achieve much.

Towards the centre of the board, R4 and R3 seem to have been 
deliberately placed where they might be subject to tracking if it occurred.

Anyone seen this kind of thing before?

BTW, for those in Australia, this is an Ozito PXCG-030.

I haven't been able to determine whether it's faulty yet. No obvious 
smoked has escaped. It puts no significant voltage onto the output pins, 
but it contains a microcontroller, and also has a communication 
connection to the battery, so it seems entirely possible that it won't 
supply charge until it determines that a battery is connected.

Sylvia.
On 9-12-2018 4:25, Sylvia Else wrote:
> This charger claimed that both my batteries are faulty, which seemed a > but of a coincidence, so I suspected the charger instead. > > Here's a picture of the board: > > https://www.dropbox.com/s/saeqrsralcdsc54/chargeBoard.jpg?dl=0 > > I'm puzzled by the largish round holes, both in the middle of the board, > and diagonally towards the left, in the proximity of the labels for C13 > and R43. In both cases, they're where I might have expected to find > anti-tracking slots, but holes are not going to achieve much. > > Towards the centre of the board, R4 and R3 seem to have been > deliberately placed where they might be subject to tracking if it occurred. > > Anyone seen this kind of thing before? > > BTW, for those in Australia, this is an Ozito PXCG-030. > > I haven't been able to determine whether it's faulty yet. No obvious > smoked has escaped. It puts no significant voltage onto the output pins, > but it contains a microcontroller, and also has a communication > connection to the battery, so it seems entirely possible that it won't > supply charge until it determines that a battery is connected. > > Sylvia. >
They separate mains voltage area and output part area in my opinion.
On Sun, 9 Dec 2018 14:25:46 +1100, Sylvia Else <sylvia@email.invalid>
wrote:

>This charger claimed that both my batteries are faulty, which seemed a >but of a coincidence, so I suspected the charger instead. > >Here's a picture of the board: > >https://www.dropbox.com/s/saeqrsralcdsc54/chargeBoard.jpg?dl=0 > >I'm puzzled by the largish round holes, both in the middle of the board, >and diagonally towards the left, in the proximity of the labels for C13 >and R43. In both cases, they're where I might have expected to find >anti-tracking slots, but holes are not going to achieve much. > >Towards the centre of the board, R4 and R3 seem to have been >deliberately placed where they might be subject to tracking if it occurred. > >Anyone seen this kind of thing before? > >BTW, for those in Australia, this is an Ozito PXCG-030. > >I haven't been able to determine whether it's faulty yet. No obvious >smoked has escaped. It puts no significant voltage onto the output pins, >but it contains a microcontroller, and also has a communication >connection to the battery, so it seems entirely possible that it won't >supply charge until it determines that a battery is connected. > >Sylvia.
I've seen some chargers that wouldn't even try to charge a zero-volt battery. It's almost as if some of their circuits are powered by the battery being charged. Open circuit, the charger's output is zero. Strange. The fix is to partially charge the battery with a bench supply to bootstrap the process. -- John Larkin Highland Technology, Inc lunatic fringe electronics
On 9/12/2018 3:09 pm, John Larkin wrote:
> On Sun, 9 Dec 2018 14:25:46 +1100, Sylvia Else <sylvia@email.invalid> > wrote: > >> This charger claimed that both my batteries are faulty, which seemed a >> but of a coincidence, so I suspected the charger instead. >> >> Here's a picture of the board: >> >> https://www.dropbox.com/s/saeqrsralcdsc54/chargeBoard.jpg?dl=0 >> >> I'm puzzled by the largish round holes, both in the middle of the board, >> and diagonally towards the left, in the proximity of the labels for C13 >> and R43. In both cases, they're where I might have expected to find >> anti-tracking slots, but holes are not going to achieve much. >> >> Towards the centre of the board, R4 and R3 seem to have been >> deliberately placed where they might be subject to tracking if it occurred. >> >> Anyone seen this kind of thing before? >> >> BTW, for those in Australia, this is an Ozito PXCG-030. >> >> I haven't been able to determine whether it's faulty yet. No obvious >> smoked has escaped. It puts no significant voltage onto the output pins, >> but it contains a microcontroller, and also has a communication >> connection to the battery, so it seems entirely possible that it won't >> supply charge until it determines that a battery is connected. >> >> Sylvia. > > I've seen some chargers that wouldn't even try to charge a zero-volt > battery. It's almost as if some of their circuits are powered by the > battery being charged. Open circuit, the charger's output is zero. > Strange. > > The fix is to partially charge the battery with a bench supply to > bootstrap the process. >
I opened up the battery cases, to find a circuit board of a level of complexity that wouldn't be amiss in a smart phone. It eventually occurred to me the check the voltages across the lithium ion cells. Each battery had a number of cells showing 3.6V, and one showing 0.7V. The one showing 0.7V was in a different relative position in each case. One battery also had a cell showing 2.4V. So it looks like both batteries really have failed, and the charger is probably OK. I'd swap out the cells, to make one good battery, but they've been spot-welded in series. I got about 3 years 6 months life out of them. I'm just a bit suspicious that the warranty was for 3 years. Sylvia.
On Sun, 9 Dec 2018 15:43:45 +1100, Sylvia Else <sylvia@email.invalid>
wrote:

>It eventually occurred to me the check the voltages across the lithium >ion cells. Each battery had a number of cells showing 3.6V, and one >showing 0.7V. The one showing 0.7V was in a different relative position >in each case. One battery also had a cell showing 2.4V. So it looks like >both batteries really have failed, and the charger is probably OK. > >I'd swap out the cells, to make one good battery, but they've been >spot-welded in series.
Try this trick for reviving the cell first: DIY: How to revive a dead 18650 (or any) Li-ion battery cell <https://www.youtube.com/watch?v=tbEfhPbqTDE> (4:36) Crude spot welder for battery pads: <https://www.youtube.com/watch?v=UU7QC5Uby6M> (4:01) I use a 12V 20AH AGM battery, relay, push button, and an eBay timer. However, I use two copper electrodes and no "ground" clamp to the LiIon cell. Like this: DIY Battery Spot Welder - Update & Demonstration <https://www.youtube.com/watch?v=b_kGgPVrcCI> (23:46)
>I got about 3 years 6 months life out of them. I'm just a bit suspicious >that the warranty was for 3 years.
There is probably a warranty timer built into the battery packs. -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558
On Sat, 08 Dec 2018 21:37:06 -0800, Jeff Liebermann <jeffl@cruzio.com>
wrote:

>Try this trick for reviving the cell first: >DIY: How to revive a dead 18650 (or any) Li-ion battery cell ><https://www.youtube.com/watch?v=tbEfhPbqTDE> (4:36)
Also, if your cells have a CID reset (short circuit protection), you can reset it using one of these methods: <https://www.youtube.com/results?search_query=cid+reset> Do this only if the battery shows 0.00V, not 0.7V. -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558
On 09/12/2018 03:25, Sylvia Else wrote:
> This charger claimed that both my batteries are faulty, which seemed a > but of a coincidence, so I suspected the charger instead. > > Here's a picture of the board: > > https://www.dropbox.com/s/saeqrsralcdsc54/chargeBoard.jpg?dl=0 > > I'm puzzled by the largish round holes, both in the middle of the board, > and diagonally towards the left, in the proximity of the labels for C13 > and R43. In both cases, they're where I might have expected to find > anti-tracking slots, but holes are not going to achieve much. > > Towards the centre of the board, R4 and R3 seem to have been > deliberately placed where they might be subject to tracking if it occurred. > > Anyone seen this kind of thing before? > > BTW, for those in Australia, this is an Ozito PXCG-030. > > I haven't been able to determine whether it's faulty yet. No obvious > smoked has escaped. It puts no significant voltage onto the output pins, > but it contains a microcontroller, and also has a communication > connection to the battery, so it seems entirely possible that it won't > supply charge until it determines that a battery is connected. > > Sylvia.
Try trickle charging the low volt cell... 5V with series resistor will do.. 100mA ? --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus
On 9/12/2018 4:37 pm, Jeff Liebermann wrote:
> On Sun, 9 Dec 2018 15:43:45 +1100, Sylvia Else <sylvia@email.invalid> > wrote: > >> It eventually occurred to me the check the voltages across the lithium >> ion cells. Each battery had a number of cells showing 3.6V, and one >> showing 0.7V. The one showing 0.7V was in a different relative position >> in each case. One battery also had a cell showing 2.4V. So it looks like >> both batteries really have failed, and the charger is probably OK. >> >> I'd swap out the cells, to make one good battery, but they've been >> spot-welded in series. > > Try this trick for reviving the cell first: > DIY: How to revive a dead 18650 (or any) Li-ion battery cell > <https://www.youtube.com/watch?v=tbEfhPbqTDE> (4:36) > > Crude spot welder for battery pads: > <https://www.youtube.com/watch?v=UU7QC5Uby6M> (4:01) > I use a 12V 20AH AGM battery, relay, push button, and an eBay timer. > However, I use two copper electrodes and no "ground" clamp to the > LiIon cell. Like this: > DIY Battery Spot Welder - Update & Demonstration > <https://www.youtube.com/watch?v=b_kGgPVrcCI> (23:46) > >> I got about 3 years 6 months life out of them. I'm just a bit suspicious >> that the warranty was for 3 years. > > There is probably a warranty timer built into the battery packs. >
That's what I was suspicious of. Clearly it wouldn't be difficult to design such a thing into a device that has its own power supply. Though I think if a company in Australia did this, and they got caught out, they'd be in serious trouble (Ozito is a brand name for one of the big hardware store chains here). It doesn't look to me as if there's any provision for charge equalisation, and by the same token, I don't see how the circuit could intentionally kill one cell, or just fail to charge it. Sylvia.
On 12/9/2018 6:56 PM, Sylvia Else wrote:
> On 9/12/2018 4:37 pm, Jeff Liebermann wrote: >> On Sun, 9 Dec 2018 15:43:45 +1100, Sylvia Else <sylvia@email.invalid> >> wrote: >> >>> It eventually occurred to me the check the voltages across the lithium >>> ion cells. Each battery had a number of cells showing 3.6V, and one >>> showing 0.7V. The one showing 0.7V was in a different relative position >>> in each case. One battery also had a cell showing 2.4V. So it looks like >>> both batteries really have failed, and the charger is probably OK. >>> >>> I'd swap out the cells, to make one good battery, but they've been >>> spot-welded in series.
YOu can cut the tabs and solder the tabs together with a short piece of wire. Just don't let any heat get to the cell. Problem is that it will make the cell too long to fit back in the case. Another issue is that the charge controller will notice that you've disconnected the power and take a dirt nap. I never found any way to reset a lithium charge controller chip after replacing one or more cells. It's surely possible, cuz they have to do it at the factory, but it's secret info. Often does work with NiCd...but not lithium.
>> >> Try this trick for reviving the cell first: >> DIY: How to revive a dead 18650 (or any) Li-ion battery cell >> <https://www.youtube.com/watch?v=tbEfhPbqTDE>&nbsp; (4:36) >> >> Crude spot welder for battery pads: >> <https://www.youtube.com/watch?v=UU7QC5Uby6M>&nbsp; (4:01) >> I use a 12V 20AH AGM battery, relay, push button, and an eBay timer. >> However, I use two copper electrodes and no "ground" clamp to the >> LiIon cell.&nbsp; Like this: >> DIY Battery Spot Welder - Update & Demonstration >> <https://www.youtube.com/watch?v=b_kGgPVrcCI>&nbsp; (23:46) >> >>> I got about 3 years 6 months life out of them. I'm just a bit suspicious >>> that the warranty was for 3 years. >> >> There is probably a warranty timer built into the battery packs. >> > > That's what I was suspicious of. Clearly it wouldn't be difficult to > design such a thing into a device that has its own power supply. Though > I think if a company in Australia did this, and they got caught out, > they'd be in serious trouble (Ozito is a brand name for one of the big > hardware store chains here). > > It doesn't look to me as if there's any provision for charge > equalisation, and by the same token, I don't see how the circuit could > intentionally kill one cell, or just fail to charge it. > > Sylvia. >
On 09/12/2018 19:08, TTman wrote:
> On 09/12/2018 03:25, Sylvia Else wrote: >> This charger claimed that both my batteries are faulty, which seemed a >> but of a coincidence, so I suspected the charger instead. >> >> Here's a picture of the board: >> >> https://www.dropbox.com/s/saeqrsralcdsc54/chargeBoard.jpg?dl=0 >> >> I'm puzzled by the largish round holes, both in the middle of the >> board, and diagonally towards the left, in the proximity of the labels >> for C13 and R43. In both cases, they're where I might have expected to >> find anti-tracking slots, but holes are not going to achieve much. >> >> Towards the centre of the board, R4 and R3 seem to have been >> deliberately placed where they might be subject to tracking if it >> occurred. >> >> Anyone seen this kind of thing before? >> >> BTW, for those in Australia, this is an Ozito PXCG-030. >> >> I haven't been able to determine whether it's faulty yet. No obvious >> smoked has escaped. It puts no significant voltage onto the output >> pins, but it contains a microcontroller, and also has a communication >> connection to the battery, so it seems entirely possible that it won't >> supply charge until it determines that a battery is connected. >> >> Sylvia. > Try trickle charging the low volt cell... 5V with series resistor will > do.. 100mA ?
Better to use a bench power supply with the voltage set to <4.2V and the current limit set to whatever you want the charging current to be.