Minelab GPX6000 Battery Question

[Moneybox]

Did a web link show on the bottom of your screen when you took the photo?

No we can't read it.

 

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Description​

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Brand: Panasonic
Capacity (Ah): 3.4 Ah (3400mAh)
Charging voltage (V): 4.2 V.
Energy (Wh): 12.2 Wh
Energy density (Wh / L): 730 Wh / L.
Nominal voltage (V): 3.6V-3.7V
Diameter (mm): 18.06 mm (+/- 0.03 mm)
Height (mm): 65 mm (+/- 0.03 mm)
Pulse current (5-6 seconds): 12A
Top (front): flat top
Model: NCR18650B
Made in Japan

 

[Moneybox]

Maybe I can stretch the budget to one of these too.

 

[XLOOX]

This looks like my best option,

18650 Batteries, Lithium Batteries

Panasonic NCR18650B 3400mAh Li-Ion Battery (Flat Top) With Tabs​

Higher capacity and longer life, Panasonic 18650 Li-ion batteries are commonly used in: torches, clocks, toys, cameras, and many other electronic devices.

18650B Panasonic battery with tabbed connection points.

Model: NCR18650B (Tabbed)
Voltage: 3.6V
Tabs: Yes
Rechargeable: Yes
Nominal capacity: 3400mAh
Discharge: 10A
Diameter: 18mm
Height: 65mm
IEC: 18650
Chemistry: Li-Ion

Commonly Known As:
• CR18650, NCR18650B

$22.91 each from Ausbatteries

Yes, that battery is perfect but $22 ea is v expensive. I normally get them from Lanplus Australia. Looks like they are OOS but they have the Sony VTC range for $14 ea.

Just for others info, since the ML cell is 65-66mm long it is unlikely to be a "protected cell" as protected cells are closer to 68mm as they have a small BMS PCB on the end.

For this application you DONT want the type of cells with a built in BMS PCB ie( battery management system printed circuit board) as they will get confused with 4 of them acting independently.

battery welder will pay for itself over and over again - wait until you start repacking your $250 Makita 18V 5Ahr batteries for $90...

 

[Moneybox]

Yes, that battery is perfect but $22 ea is v expensive. I normally get them from Lanplus Australia. Looks like they are OOS but they have the Sony VTC range for $14 ea.

Just for others info, since the ML cell is 65-66mm long it is unlikely to be a "protected cell" as protected cells are closer to 68mm as they have a small BMS PCB on the end.

For this application you DONT want the type of cells with a built in BMS PCB ie( battery management system printed circuit board) as they will get confused with 4 of them acting independently.

battery welder will pay for itself over and over again - wait until you start repacking your $250 Makita 18V 5Ahr batteries for $90...

I hope I didn't make a blunder. I bought the AliExpress ones, 4 for $14.56 along with the welder.

 

[XLOOX]

I hope I didn't make a blunder. I bought the AliExpress ones, 4 for $14.56 along with the welder.

At that price they prob wont last as many cycles as an 1st grade cell but only one way to find out.

At worst it will be good battery spot welding practice.

Just make 100% sure you know which wires go to which cells + & - .

I like to mark the wires with blue/red/black/white artline in unique stripes and take photos from a few angles BEFORE I desolder them so I have a reference.

Actually i wouldnt even try and use the $3.50 Aliexpress ones for the AEG battery packs as, unlike the 6000,which is only drawing 750mA, drills etc draw high current and unless they are decent cells they will be stuffed in a couple of cycles.

 

[XLOOX]

For interest, like the GPX6000 battery , the SDC lithium battery pack is also just 4 x 18650 cells but why charge people $80 (SDC battery) when you can charge them $240 (GPX6000)?

 

[davsgold]

This looks like my best option,

18650 Batteries, Lithium Batteries

Panasonic NCR18650B 3400mAh Li-Ion Battery (Flat Top) With Tabs​

Higher capacity and longer life, Panasonic 18650 Li-ion batteries are commonly used in: torches, clocks, toys, cameras, and many other electronic devices.

18650B Panasonic battery with tabbed connection points.

Model: NCR18650B (Tabbed)
Voltage: 3.6V
Tabs: Yes
Rechargeable: Yes
Nominal capacity: 3400mAh
Discharge: 10A
Diameter: 18mm
Height: 65mm
IEC: 18650
Chemistry: Li-Ion

Commonly Known As:
• CR18650, NCR18650B

$22.91 each from Ausbatteries

yep 18650 with tags is much easier then the button tops to do the replacement, just follow the way they have them setup and you'll be fine.

those ones your looking at 3400mAh and when link 2 in parallel gives you 6800mAh of run time at 1mAh per hour and seeing the detector don't use 1mAh per hour you will get about the same run time.

And the volts at 3.6v when you link 2 of them together in series you get 7.2v which will give you the same as the originals

so you have 2 of them in parallel and 2 of then in series and it all works out ok

 

[XLOOX]

We have four batteries 66mm x 18mm.

View attachment 16261

Suggest marking the existing red cells 1-4 and then when you remove them checking their individual voltages. A Li-Ion cell is flat when under 3V.

Then put all 4 on an an external Li-Ion charger. If you find only 1 cell is/was flat you can reuse the others.

Best if you keep same age/capacity cells together so you can use the recovered cells elsewhere or wait until your next 6000 battery dies and make 1 good one out of the 2 dead ones.

If all were flat but after external charging now all (3.4-4.2V) and stay that way for a week then issue might be the ML BMS PCB ( you can see it on the RHS of the cells in your photo. If BMS is stuffed then you are as well. You can actually buy generic BMS PCBs but it starts to get all too hard.

 

[A-team]

I've had an in-depth look into this over the last 12 months. Turns out, the cells are average and generally not the problem. The main issues lay in the BMS which is over protective and under capable. I've spoken to electronics technicians and even Minelab (who as expected, don't admit to anything). The Battery Management System incorporates temperature, current and voltage monitoring. I have had the temperature sensor "misread", the current protection fuse go open circuit, had the BMS do a safety shutdown. There are various ways that the circuit manages what it sees and reacts accordingly. On one hand, it's great to have multiple safety protocols, on the other, it seems that not enough real world testing was done on the design resulting in people experiencing various faults and failures. This is a major shortcoming of Minelab and their GPX6000. When you speak to Minelab or some of the dealers, they say there has been very few battery issues. When you talk to actual 6000 owners, the truth comes out. Also, the flat face pogo pin connection system is underrated for the current transfer. There are many, better options, starting with concave pogo pins, then the simple terminals as used on power tool battery packs. A simple solution would be to redesign and upgrade the BMS systems. For those electronically handy, you can rip out the BMS and use 2 pre made boards from AliExpress to cover charge and discharge functions reliably. The only issue is that they don't have indicator lights for charge state. I won't mention exactly what needs to be done to avoid any liability. And yes, you can always upgrade the 18650 cells to better quality and slightly higher capacity, but truely, the existing ones are sufficient if only the BMS was....

 

[grubstake]

It sounds like there's an opportunity for the independent Minelab repairer/modifiers to offer GPX6000 battery upgrades, incorporating all of the above features. Minelab have had long enough to produce a much-needed revamp themselves, but seem happy to just keep raising prices without addressing well-known product weaknesses.

 

[Hawkear]

I had a damaged laptop and disassembled the battery pack and ended up with about 7 perfectly good 18650 cells. The battery cells are well and truly sealed within a tough plastic casing, but some judicious surgery can open that up to allow the cells to be removed. Just be careful not to stab any of the cells.
They have flat tabs at each end, and you need check and mark the polarity to avoid insertion mistakes. I have a Nitecore 18650 charger and they seem to charge OK with that.
I used these in my 2300 with spacers and they worked well until deciding to go with Minelab's 2300 lithium battery pack for convenience reasons.
I still use some of them in other gadgets I have like torches.

 

[A-team]

It sounds like there's an opportunity for the independent Minelab repairer/modifiers to offer GPX6000 battery upgrades, incorporating all of the above features. Minelab have had long enough to produce a much-needed revamp themselves, but seem happy to just keep raising prices without addressing well-known product weaknesses.

When you see the simplicity of it. The job is minimal. There are caveats, the repairer needs to be a competent solderer and understand the dangers of lithium ion chemistry. Past that, a pack can be rebuilt with batteries and BMS for $20 to $30. And charge anything up to the new price of a battery. Major incentive!!!!!