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I need a bit of advice about replacing cells
#1
I own one of these “eiger” under the hood work lights. These eiger lights are very similar, if not the same, under the name Braun in USA. 
I really like this light because it spreads the light very well unlike some other lights that concentrates the light mainly in one spot.
However, the main issue with these lights is the battery run time.
If you live in a block of flats like I do and you don’t have electricity in the garage, you rely  heavily on battery power to power up your lights and tools. 
Oubviously during lockdown I spent  a bit of time in the garage and this light in max power only lasts around 2 hours if so.
Then I need to bring it home to charge it up for 6 hours (Yes it takes 6 bloody long hours) and then take to the garage again.
I had enough of carrying the light all the time with me so I thought about a solution/hack.

I’m aware of some battery holders for 18650s that you can put them in parallel. From my research, if I keep the 18650 cells in parallel, I keep the same voltage as my existing cell, 4.2v fully charged cell, but I will increase the capacity or run time. The cell I have at the moment inside the light is 2000mah. So I guess putting 4x 18650 cells in parallel I should end up with 8000mah? This total figure is bearing in mind that the cells I put in the battery holder are 2000mah, Correct? Oubviously I will take the existing cell out and use the existing wiring that goes from the cell to the pcb.
I was thinking about buying a few 18650 with the button top, I heard they are safer because they have a bms in it. I just don’t know if we can use 4 of these 18650 button top cells in parallel to power up whatever we need to. Will the bms inside of each cell start conflicting with each other?

Other way I was thinking of, was using a power bank and connect the power bank to the light using a usb wire. My concern is, as the power bank will be giving out 5v, will I fry the pcb inside the light?
I will upload a few pics of the pcb inside of the light's handle.

Thanks in advance

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#2
So it contains one cell right now? Then putting more cells in parallel should work without any changes to the electronics. Light time will be longer, but charging time as well. You could use a holder where cells are replaceable and then charge them outside of the lamp with a Opus charger or similar. Use glass fuses to parallel the cells and only charge/replace all cells at the same time.

How about some solar panels on the roof and a “real” battery? :-)
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#3
(08-05-2020, 06:40 AM)stevelectric Wrote: So it contains one cell right now? Then putting more cells in parallel should work without any changes to the electronics. Light time will be longer, but charging time as well. You could use a holder where cells are replaceable and then charge them outside of the lamp with a Opus charger or similar. Use glass fuses to parallel the cells and only charge/replace all cells at the same time.

How about some solar panels on the roof and a “real” battery?  :-)
Thanks for your reply.
Yes, there is one 18650 cell inside the light, but doesn't last long on max power, just around 2 hours. As you mentioned, my plan is to buy one of those cell holders, (maybe a 4 cell holder) and charge the cells outside the holder in a 4 slot litokala charger. The reason I asked in my post if button top cells could be used in parallel, it is because they supposedly have protection against over discharge while the cells I have around, they don't have any bms in it, I just harvested them from a cordless hoover.
Regarding solar panels, I thought about that. For now I have to wait. Plus I need to ask permission to the management company and it is not guaranteed they will give me permission to get one installed.
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#4
+1 adding cells in parallel is a great idea.
However, 99% sure this will slow the charge time dramatically too.
If you added a separate 18650 charge cct feeding into the red & black battery wires, you could have a faster charge happening.
Eg a TP5000 or trusty TP4056 board, feed with a 5V/3A DC adaptor.
Or a CV/CC charger module like these from eBay or AliExpress:
"Lithium Charger CV CC Buck Step Down"
https://www.ebay.com.au/itm/5A-Lithium-C...3444101787
You could use a 12V adaptor & charge a few parallel cells in 2-3hrs (depending on cell mAhr, etc)

If you took it a step further, you could make several modular battery packs of say 6 parallel cells & put a plug in-line with the red/black wires.
Swap & rotate the packs, go for hours...
Running off solar, DIY & electronics fan :-)
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#5
Thanks guys for your replies.
I decided to make an experiment as I have plenty of power tool batteries around, Ryobi, Parkside, Worx.
I hooked up a female cigarette lighter socket to one of the battery packs and then a 12-24V USB cigarete lighter plug into it, so it provides 5v via usb cable. I soldered the usb cable to the red and black wires in the light’s pcb. It gets a bit warm around the pcb, but it works.
It may not be the most efficient way, but for sure using a 4ah battery pack it lasts for ages.
It also works using a powergen power bank that I bought years ago that provides 5v via USB.

(08-05-2020, 08:51 AM)Redpacket Wrote: If you took it a step further, you could make several modular battery packs of say 6 parallel cells & put a plug in-line with the red/black wires.
Swap & rotate the packs, go for hours...
I order to make these "modular battery packs of say 6 parallel cells & put a plug in-line" do I need unprotect cells or the button top ones, protected/with the bms in the cell itself?
I guess I may need to look on YouTube on how to make them.
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#6
Basically you are making packs & ideally each pack should have its own 6s BMS rated maybe 20A (half than is the real number) from eBay, etc.
I'd go one BMS for the pack vs cells with a BMS inside each one.
Button or not doesn't really matter.
Result like this:
http://www.batterysupports.com/222v-252v...p-136.html
Running off solar, DIY & electronics fan :-)
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#7
You gotta be shi&@ting me! I bought a pack of 2 'Click' branded tube lights from Bunnings a few years ago when they were on clearance, and from your pics, the housing looks identical with a different circuit board.

Took one camping a couple of times, and the light output is great for a gazebo. I to was disappointed that the light only lasted a couple of hours. I finally decided - like only a couple of months ago, to get into it and see what's up with that. I started by removing the 4 screws of end cap, seeing no screws I drilled a hole... and noticed a screw, and that that part unscrewed from the housing! Removed the next 4 screws to reveal a sealed hollow. DOH, so I drilled through to see a circuit board. HOW did they get this thing together?? Eventually I figured out that the large inner hex ring twisted (Righty loosey) to reveal how the handle connected to the tube. OMG! I'll know for the other one Tongue

So, I found the single cell in question and capacity tested it. 1st attempt was barely 600mAh. Second got it up to around 1800mAh.

So, I reamed out the end of the cell holder to allow cells to protrude further into the tube...



I had a couple of goes to make a pack that would fit. I used 3 x Samsung 25R (yes in parallel) - Works a treat and lasts as long as I need. Yes, takes hours to charge, but it's got all day to charge.


The other one I plan to fill the whole barrel! I might even look at an alternate charge circuit using a TP5000 or some such.
-----------------------------------------------------------------------------------------------------------------------------------------------------------
As at Mid May 2020 -Total cells 1,135/Shucked 1,045/To be shucked 90/Processed 194/To be processed 608/Zero volt 183/Bad/rusted 19/Sanyos 1/21700s 24
All tool batteries comprising of Milwaukee, Makita, AEG, Hilti, with Samsung, LG, Sony and Sanyo cells from 1.3AH to 3.0AH (OEM)
Chargers... 1 x Nitecore D4/1 x LiitoKala 500/1 x iMAax B6AC
On order... 5 x LiitoKala 500/1 x LiitoKala 500/1 x iCharger 4010 Duo
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#8
(08-17-2020, 01:39 AM)Wayne\s World Wrote: You gotta be shi&@ting me! I bought a pack of 2 'Click' branded tube lights from Bunnings a few years ago when they were on clearance, and from your pics, the housing looks identical with a different circuit board.

Took one camping a couple of times, and the light output is great for a gazebo. I to was disappointed that the light only lasted a couple of hours. I finally decided - like only a couple of months ago, to get into it and see what's up with that. I started by removing the 4 screws of end cap, seeing no screws I drilled a hole... and noticed a screw, and that that part unscrewed from the housing! Removed the next 4 screws to reveal a sealed hollow. DOH, so I drilled through to see a circuit board. HOW did they get this thing together?? Eventually I figured out that the large inner hex ring twisted (Righty loosey) to reveal how the handle connected to the tube. OMG! I'll know for the other one Tongue

So, I found the single cell in question and capacity tested it. 1st attempt was barely 600mAh. Second got it up to around 1800mAh.

So, I reamed out the end of the cell holder to allow cells to protrude further into the tube...



I had a couple of goes to make a pack that would fit. I used 3 x Samsung 25R (yes in parallel) - Works a treat and lasts as long as I need. Yes, takes hours to charge, but it's got all day to charge.


The other one I plan to fill the whole barrel! I might even look at an alternate charge circuit using a TP5000 or some such.
You are like me, I don't really care how long it takes to charge the cells up as long I can have the longest run time as possible.
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#9
With the tube full of cells, it'd likely be 2 days lol. I do wonder if they'd get enough current to do a proper job.
-----------------------------------------------------------------------------------------------------------------------------------------------------------
As at Mid May 2020 -Total cells 1,135/Shucked 1,045/To be shucked 90/Processed 194/To be processed 608/Zero volt 183/Bad/rusted 19/Sanyos 1/21700s 24
All tool batteries comprising of Milwaukee, Makita, AEG, Hilti, with Samsung, LG, Sony and Sanyo cells from 1.3AH to 3.0AH (OEM)
Chargers... 1 x Nitecore D4/1 x LiitoKala 500/1 x iMAax B6AC
On order... 5 x LiitoKala 500/1 x LiitoKala 500/1 x iCharger 4010 Duo
Reply
#10
(08-18-2020, 04:23 AM)Wayne\s World Wrote: With the tube full of cells, it'd likely be 2 days lol. I do wonder if they'd get enough current to do a proper job.
If you go camping a lot, another good light to consider is the Ryobi R18ALF-0 ONE+ Folding Area Light. I also own one of these and they are brilliant. I'm considering buying another one if I see them at a good price. Here in Uk, you hardly ever see one for sale second hand. Another day I saw a second hand one sold on ebay more expensive than brand new. Why people don't shop around is beyond me. Smile
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