Test/review of Keeppower 18350 1200mAh UH1835P (Black) 2017

[Correllux]

You are most welcome! I’m detailed and methodical like you are, I just don’t usually show it.

I had to ask about the 3.9v because aside from maybe obvious reasons, you could be up to anything - anything at all! I missed your original comment about using these for a power tool. That sounds like an interesting application for such little cells! If you end up doing it, please post and let us know how it performs. Would this go in a relatively dumb tool, or will there be challenges to address with any onboard electronic controllers and such?

Reminds me, one of these days I need to try and source a good bi-axial led to put into my drill. Some of the newer drills/brands are finally using warmer emitters and flat chips instead of ye olde colde bleue junk…a nice change, about ten years late to the party.

[Barkuti]

Wellp, today I spoke with the fellow of me which was considering a battery overhaul for its old DC735 drill, but since he is surprised by how well the aforementioned knock-off or lesser quality battery performs, and he also knows about the BU-807: How to Restore Nickel-based Batteries which I can do for him on his oldest battery… he’s not very enticed by the major overhaul that the li-ion modification implies. I guess that he has enough, particularly with its main battery which I built for him long ago with top quality Ni-MH cells, balancing connector and also a battery balancer following this guide: Balancing Ni-MH Battery Packs @ Electro Schematics. He told me he always uses the battery balancer with that battery (made with “Turnigy 4200” cells), and now I can see the difference because I also built another battery pack with cells from the same provider/rewrapper for him (with “Turnigy 5000” cells) and that one died due to multiple cell reversal and etc. Of course more than likely he screwed up with the battery (without BMS protection, you have to know when to cut and its best to put a discharged battery inmediately in the charger for at least a small while, to quickly undo any possible cell reversals), but I also think that keeping these high performance cells regularly balanced is of great importance, particularly if cell consistency (in both capacity and self-discharge) is less than desirable.

In any case, thanks again for the provided data Correllux (and Limsup too).

[Correllux]

Well it would have been a fun project anyway! Hopefully this thread will see some input from more people as to how these cells are behaving and aging.

[Jeffgoldblum]

@Barkuti

You can read BU-808: How to Prolong Lithium-based Batteries for more detailed information. I also use this advice for my smartphone battery, but since smartphone batteries are high voltage types I’ve boiled down or summarized the lesson into a proportion: 14:15, which is exactly 3.92/4.2 (V). So, the limit voltage I set for my 4.4 V smartphone battery is 4.106 V for maximum lifespan.

Battery University is a great starting point. Don’t you find it kind of dated though? It hasn’t exactly kept up with the times. Most of their info is definitely still applicable but they’re not exactly on the cutting edge or using the latest research.
Like, phones don’t even use basic CC/CV charging anymore. and haven’t got years. It’s all multi-stage, optimized, adaptive.

[Correllux]

Barkuti…here we are a month later or whatever. Both cells are sitting at 3.888v

I think I’ll let them sit another month just to see what happens but I’m pretty happy with this so far.

[Barkuti]

Correlux,

It’s nice to know. Considering that the starting point was 3.895/3.894 V, which fell to 3.891/3.890 V after one day and etc., it definitively looks like the self-discharge of these cells tapered considerably and is really really low.
Other than this, remember that to me that was enough already, so only continue if you are really willing to do so by your own will.

[Correllux]

It’s all for science now.

Curious about Limsup’s cells, though…that is a little concerning in the larger picture. When I stop this run I’ll charge them up fully and see how the drop fares on the upper end.

[Wingman]

Last year I bought a (single) UH1835P from Nkon, which came with a really low voltage (sub-3V atleast, but forgot how low). Since it was only a single battery (and had a lot of stuff on my mind) I didn’t bother complaining to Nkon.

Charged the cell carefully and it stayed quite cool, so I used it in a flashlight, but leaving it charged up in that flashlight, I noticed it had dropped a lot in terms of voltage after 3-4 weeks.

I’ve taken it out of the flashlight, charged it up again, stored it (outside the flashlight) for a while, but again the battery had self-discharged quite a lot. Given the fact that this battery came from the seller with a very low voltage, I just figured it must have turned bad because of going so low and I wrote the cell off.

Reading several other people had self-discharge problems with this cell, I wonder to which extend my cell is “crap” due to discharging so low, or that it’s just a bad/subpar cell anyway.

EDIT:
Found some notes about this cell’s self discharge. Only measured it (with a “cheap” DMM: ANENG AN8009) a few random times, so it’s far from scientific/complete, but just to give an idea:

date (d/m/y)
02-05-2022: 3,961V
09-05-2022: 3,888V
17-05-2022: 3,845V
31-08-2022: 3,383V
02-04-2023: 1,709V

As you can see there is a large gap between last few measurements. I know that I’ve done a few measurements in between, but didn’t write them down. I know it had dropped below 3V after which I stopped writing down measurements (until today), also because I had already “written this cell off”, so I didn’t bother with keeping up with it’s discharge rate. (Decided to let the cell drain down completely and disregard of it.)

[Barkuti]

Just dropped by around here…
Nice to know, Wingman. I’d say that UH1835P you received from Nkon was already faulty to start with, being a cell with abnormally high self-discharge, which is the reason you received it at an abnormally low voltage.
This does not speak very well about the quality consistency of these cells. A li-ion cell with abnormally high self discharge is a dead cell, in my opinion, as it will kill itself after a while in storage. I discard cells like this for safety reasons.

[Wingman]

I also will discard this cell. I stored it in a safe place and now I let it drain itself untill it’s almost empty and then I will dispose of it (properly).

I will look for some other 18350 cell(s), but unfortunately my ‘normal supplier’ (Nkon) hasn’t got much choice in that size, at the moment.

[Jeffgoldblum]

@Wingman

I also will discard this cell. I stored it in a safe place and now I let it drain itself untill it’s almost empty and then I will dispose of it (properly).

I will look for some other 18350 cell(s), but unfortunately my ‘normal supplier’ (Nkon) hasn’t got much choice in that size, at the moment.

It’s drained low enough there’s not enough energy left in there to do anything. Throw some tape over the terminals if you want and you’re good to go. See if there’s a recycling program for them in your area. Here they just have bins outside hardware stores you can toss them in.

[Wingman]

I know, was planning on putting the cell in the recycling bin this week. I always put tape on both ends (just as good measure) when turning in bad/empty Li-ion cells. (Specificly Li-ion, other cells I will just put them in the bin without tape.)

Going to buy some new 18350’s, but it aint going to be keeppower’s this time!

[Jeffgoldblum]

There’s no use putting it in the recycling bin, it can’t be recycled like normal household stuff. Unless your country has a very advanced recycling program. They might, I’m not sure. Differentt countries/states have different ways of doing it, I’m not sure how it works where you are.

But it would be considered hazardous waste and is probably supposed to be disposed of similar to however your country/state disposes of old car batteries or used motor oil. In my province in Canada they have specific battery drop off locations around town. It’s not fancy though, its literally just a garbage can that say “batteries only” on them. Usually outside a hardware store or an electronics store.

I don’t know what the process is where you live though.

But do whatever. I’m not recycling enforcement guy. Idk how much of that stuff actually gets recycled anyways. Go to the lake and throw them at ducks lol I won’t call the police. Sounds like a good time actually

[Wingman]

Let me rephrase/explain the recycling bin thing: here in the Netherlands you can turn in all types of batteries in one and the same bin, after which they get sorted somewhere else.

I’m not sure what specificly happens with li-ion cells, but all types of cells end up in the same bin regardless.

[Henk4U2]

In NL stores that sell batteries are obliged to accept old/depleted batteries. To make it simple for the customers, there is a “hole in the wall” where you can throw in your alkalines, coin-batteries, rechargeables etc. You don’t have to wear a sorting hat. They do.

[Jeffgoldblum]

Ok cool. Ya same thing here. Throw em in.

Over here we have to go to the bin tho they don’t come collect it.

@Henk4U2

In NL stores that sell batteries are obliged to accept old/depleted batteries. To make it simple for the customers, there is a “hole in the wall” where you can throw in your alkalines, coin-batteries, rechargeables etc. You don’t have to wear a sorting hat. They do.

Cool. That’s what it’s like here too except there’s no hole it’s just a garbage can buy the entrance. Sometimes you go to the one by the hardware store and there’s like a whole Makita 18v battery just sitting on top. Like, I shall take that thank you goodbye.
But stores are only required to take car batteries. Regular batteries some store take some don’t.