Looking for flashlight options that would be safe and compatible to run salvage cells from old ryobi, dewalt, makita, etc. power tool battery packs.
I have several Convoy S2+ hosts I built into triples that I use salvaged cells from a Lenovo Thinkpad. Works fine. I recommend using a good external charger so you know that the cells are being charged properly and don’t leave them unattended while charging. As long as they charge ok, you shouldn’t have a problem in a flashlight.
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Would this one work?
Convoy S2+ sst40
Convoy S2+ with luminus sst40 ,copper DTP board and ar-coated inside, Temperature protection,18650 flashlight,torch light
As long as the cell charges properly, I would think it would work. Looks like the driver is max 5amp, so you can look at the markings on the cells and see what they are rated for.
I’m new to this so I think I will get a variety of convoy S2+ and see how they work.
I think the batteries I pulled out of a ryobi battery pack is a:
EVE 20P 18650 2000mAh 30A Battery
Battery link
Thank you
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You’re welcome. Something else I didn’t mention earlier, when I charge my salvaged cells, I just make sure they aren’t getting any warmer than any of my other cells while charging. I had one that started to heat up on me so I disposed of that one.
i just put them in my 2nd and 3rd level lights
i have maybe 10 of those - at least 5 are in the same place
the others just sit around the house or care or tool box, in semi handy places but rarely get used
the shelf life is usually ok even though the capacity may be low
wle
You can do whatever you want with those. Throw them in anything. As long as they aren’t damaged.
Power tools batteries are different than laptop batteries
Opened another ryobi pack.
They are Samsung INR18650-20R
I have a vapcell S4 that I have been using to test and charge the batteries. I have been following the recommendations when testing salvaged cells.
Would these batteries work in a emisar D4v2?
Again no expert but what I read was that these batteries had to be put in low out put single emitter flashlights with around 1000 lumens. Also needed to be put into single cell 18650 flashlights.
How do you match the batteries to the flashlight?
Looking at either a D4v2 or convoy s2+
Pack must’ve been a couple years old, ryobi hasn’t used Samsung 20r’s in a few years. That was one of the good ones. It’s mostly HighStar now, with some Eve’s and Lishen’s.
IF those 20r’s are still good you can put those in anything too. “Single emitter 1000 lumens” no, you can put those in anything. 8 emitters, 6000 lumens, go for it. You won’t get a long runtime but the lumens at startup will be as good as anything.
IF theyre still good. Big “if”. Like, if you did a good job at taking them out of the pack with minimal damage, if there isn’t any physical damage, if you tested voltage when you took them out and they hadn’t discharged too far in storage, if temperature during charge and discharge is normal. Requires you have an idea what normal temperatures are supposed to be during charging and discharging and youre monitoring that tho.
For those two flashlights- for the s2+ pretty much any flattop unprotected 18650 is going to be fine. D4v2 you want something rated 15a or higher, ideally. Depends on the emitter choices too.
Edit: this is all assuming the salvaged cells are in essentially perfect condition.
I haven’t tried to test or charge them yet just took them out. Came in a big battery pack like around 20 cells. Most look good but will recheck. Thank you
Before you charge or discharge anything check the voltage of each cell just with a multimeter.
I was going to follow this write up on reddit
5. Test the cells. u/Chadzy wrote this guide to testing cells. I usually only do steps 1 through 5.
- Measure cell voltage. if it’s less than 2.5v*, throw it away.
- Charge the cell. if it gets hot during charging, throw it away.
- Measure cell voltage off the charger. verify it’s between 4.1 and 4.2v.
- Wait 30 minutes.
- Measure cell voltage. if it’s fallen to less than 4v, throw it away. Otherwise record the voltage.
(Optional: Measure the internal resistance. If it’s above 250 milliohms, throw that cell out.) - Store cell for 3+ days in cool, dry place.
- Measure cell voltage. if cell voltage has fallen more than .1v from the recorded voltage, throw it away.
Good enough. What kind of charger are you using
I have a vapecell S4
Cool. Take it off automatic mode, set it to manual. Don’t let it choose the charge current by itself. On manual it should default to 500mah current, just leave it there and charge everything at 500mah for now.
Bt dub, relatively new 20r’s will show IR <20mohm on that charger
I have found the convoy s2+ is the “standard” answer for 18650 lights.
But I like the wurkkos wk03/sofirn sp18 better. It has springs at both ends so works fine with the batteries from drill packs.
Its not a buck driver light so the brightmess drops with voltage on high it starts at 800ish and it’s still close to 500lumens at the 60 minute mark and 250+ at the two hour mark, so after two hours, it’s just getting down to the level the convoy starts at… I swap batteries at the 1 hour mark and call it a 500lumen light.
If you don’t mind losing the ability to charge in the light the sp31v2.0 is a sweet light, it has a buck driver so after the initial stepdown after a couple minutes it sits at about 425lm for a full 2+ hours.
This is ignorant advice.
Most li-ion cells are rated to be discharged to 2.5V during normal use. 2.5V is the discharge cutoff, not the “do not recharge” voltage.
The “do not recharge” voltage is lower.
Samsung pack design guide shown in the 35E datasheet says 1.0V is the do not recharge voltage, and it is speaking generally about liion packs, not specifically about the 35E cell.
The “Lithium Ion Rechargeable Batteries Technical Handbook” from Sony says: “Under no circumstances should overdischarge (to 1.0 V/cell or less) be allowed to occur.”
These technical resources from the cell manufacturers indicate that 1.0V can be used generally as the minimum “do not recharge” voltage.
There are now a lot of papers related to liion cell over discharge.
For example: a paper titled “Overdischarge and Aging Analytics of Li-Ion Cells” (link to pdf) shows some cycle life tests of LCO lipo cells discharged to 2.7V, 1.5V, 0V, and -.5V. The 0V and -.5V discharged cells fail rather quickly, with the -.5V internally shorting out after 14 cycles. The cell discharged to 1.5V performs similarly to the 2.7V cell: “The cell that was cycled under the recommended voltage window lost 20% capacity of its nominal capacity after 287 cycles, Fig. 2c. After 165 cycles, the coulombic efficiency exhibits an unsteady trend due to the degradation taking place within the cell. Similarly, for the 1.5 V case, the total number of cycles reduced to 220, Fig. 2d, and the unsteady coulombic efficiency occurs at the 145th cycle. In both cases, the main degradation mechanism is the SEI thickening.”
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Is low voltage the only criteria for not using a battery. OP stated that he wanted to used reclaimed batteries from old power tools.
Dont power tools get abused while in service? They get dropped, left in the sun, made to work in harsh conditions, rain snow, etc.
Isnt it possible for the reasons mentioned above that even though the batteries may have good voltage, they may still bw dangerous to use?