Replacement 3.7 battery for LED worklamp

[carbonarc]

Hi JOEPRO. The voltage shown is the present cell amount. To assess the cell capacity stop the discharge and charge the cell until your Imax 6 indicates a full charge which for a good 18650 lipo will be no more than 4.2 volts. To begin a cell capacity test in the discharge field of the Imax 6 set the cut off to voltage to 3.0 volts. Set the discharge current to around 10% of estimated cell capacity [maybe 0.1 amps]. It is better that all charging and discharging tests are carried out whilst you are observing condition just in case something goes wrong.

 

[Kram]

Cells wont stay at 4.2v with a load, 13 seconds may be a bit quick to drop to 3.91v but that shows the quality... Given 3.4v at 1.6Ah, that cell is well under 3.2Ah.

For proper testing, and accurate results to manufacturers, it will be done at 1/20th the rating over 20 hours, but who has time for that!
More useful, is to test it at the rate it may be used for, and depending on the light, 1A may be about right.

So while cell may not be good as the advert claimed, it'll be near enough 2Ah when its done and thats not bad, useable for a light.

 

[JOEPRO]

First test not so good. Ended at 1791mah.

The original cell may have been OK so I'm charging it now to compare. It is rated at 2200mah.

 

[JOEPRO]

The whole point of this was that I wanted to not only repair but extend the life of the worklamp by upgrading its capacity.

So I just ordered a Milwaukee type cell which should fit inside with minor alterations. The link that @eddie49 suggested. Cheap postage too only a couple £ extra


Hopefully it dispatches to me in NI OK.

 

[JOEPRO]

I carried out a sand and polish of the lens which was worse for wear!





There is a hole in the lens from were hot mig wire went through. So I'll clear epoxy that to keep water out.

 

[Kram]

This reminded me I wanted to open up the cheap Fakita batteries to inspect. Circuit board and wiring looks ok, these are the cells for the small one. Not great, but cant complain when they were free with the tool!

 

[JOEPRO]

Update -

The new quality battery turned up today and I had already received the new amazon battery protection modules.

So I soldered them up just now along with longer fly leads inside the torch. Torch is working happily again. I'll need to wait until a reasonable hour in the morning to die ground some clearance inside the housing for the slightly larger battery but I'm nearly certain it will fit OK.





Then its twin which normally always worked appeared dead tonight too!! WTF! It must want a heart upgrade too

 

[Kram]

I'll need to wait until a reasonable hour in the morning to die ground some clearance inside the housing for the slightly larger battery but I'm nearly certain it will fit OK.

Wood working chisels work well for that sort of thing, slicing thin plastic. I'm often doing stuff at a late hour, for plastic you can use carbide burrs in a normal drill for much reduced noise.

If the housing is abs you can add some new battery supports using acetone/abs slurry to ensure it doesnt rattle around.

Out of interest if you get a chance, what does the larger cell measure on the tester?

 

[JOEPRO]

Out of interest if you get a chance, what does the larger cell measure on the tester?

Since this was already soldered up to its battery protection device etc I put it back together instead of further testing.

I will be ordering the same cell from the same supplier for the other torch anyway so I'll test it.

 

[JOEPRO]

This is the worklamp back together and finished. Charging up on its original charger plug now then I'll give it a test soon enough on the next car welding job planned.

The cell did fit. Was very tight fit though. So tight, a screw for the led panel had to be removed That won't matter I added some hot melt glue too. Battery bedded in a couple of dabs of holt melt too so rattle free.

Very pleased with this repair and much better than throwing out the whole lamp. Now it should also have very long run time, almost double the rated capacity of the original cell.

 

[JOEPRO]

I have a genuine Milwaukee m18 battery that has some bad cells at 0v. 2x were still showing normal voltage so I checked one of them to see if worth re using in my other torch.

It performed surprisingly poor.

 

[JOEPRO]

PS going by how long (all day) the refurbished Ring worklight took to fully recharge and turn green is a very good sign for the battery capacity

 

[JOEPRO]

Original 2nd Ring worklamp is charging up OK. I have started the run time test on the upgraded torch.

I will post results later comparing original battery and upgraded torch. Note that in the 1st lamp the original battery had a failed protection module. But when I tested the battery it still was close to it's 2200 rated capacity.

If there is a good marked difference in run time I'll still order a 2nd new upgraded cell for the 2nd torch and have both of them with fresh cells.

 

[Misterg]

I'll need to wait until a reasonable hour in the morning to die ground some clearance inside the housing for the slightly larger battery

If the new cell is slightly* longer than the old one, chances are that it has an integrated protection circuit, so wouldn’t need the additional one.

* about 2mm

 

[JOEPRO]

If the new cell is slightly* longer than the old one, chances are that it has an integrated protection circuit, so wouldn’t need the additional one.

* about 2mm

Yes that's true in some cases. In my see I went for a different size of cell, a larger and higher capacity one. It has no signs of any protection on the new cell. (Such as a thin connecting strip under the plastic wrap)

 

[JOEPRO]

Results are in

Original Ring light run time after full charge: 3 hours (2200mah rated battery)

Upgraded Ring lamp same model: 4 hours 50 mins run time (4200 mah new larger cell)

Decent upgrade for just over £10 so ill upgrade the 2nd one too

 

[JOEPRO]

Got the second new Eddie cell fitted to my other Ring worklamp. Only took about 30 mins this time from start to finish