Will charging at 1000 mA significantly reduce battery service life over 500 mA?

[bwDraco]

My current chargers output 500 mA, which is a bit too slow for my taste, so I have a faster 1000 mA charger (Nitecore UM10) coming.

Out of curiosity, will using this faster charger substantially reduce service life over a slower 500 mA charger? Should I prefer the slower charger whenever possible, or is the difference too small to be worth it? The batteries I'm working with are Nitecore NL189s (protected 18650, 3400 mAh).

—DragonLord

 

[MidnightDistortions]

Higher currents could heat the battery to the point where it can reduce life but if the batteries don't get too hot they should be ok. I kinda prefer using 500-700mAh for most of my batteries. If i am in a hurry i'll use the 1A rate, but i usually counter that problem with extra cells.

 

[ChrisGarrett]

I don't believe so, but I'm no scientist. 1A is about .34C for your cells and that seems to be a nice, benign charging rate from my readings.

There's really no way to do any testing, because all lights are different and place different loads on a cell. Concurrently, operating/storage temps will be different for every user and so coming to a hard, fast conclusion is problematic at best.

I will fast charge my NiMH at 1A, but have gone a bit higher for some of them on occasion and for my 18650s, 17760s and 26650s, it's 1A. For my 16340s it's 250mA and my 14500s, I use 500mA.

For good quality cells, I don't worry about it too much and I only keep track of purchase dates and not cycles.

Chris

 

[ScottJD]

Every battery is different, but my Samsung 18650 cells I use state that 1.3A is the recommended charge current for %100 capacity. I charge them at 1A since it's easier to throw them in my XTAR charger then breaking out the hobby charger for the 1.3A or higher charge. The specs for my cells also say they can charge at 2.6A but it says a %15 loss in capacity is expected for the fast 2.6A charging.
I think 1A for your 18650 should be fine, it shouldn't even get warm honestly if they are good cells. But I would check them the first few times during the charging to see if they are getting warm/hot. If they get hot this could be a sign of a damaged cell or just one past its lifetime of charging cycles.

How old are the batteries?
Does the charger you order monitor temperature with a safety shutoff feature if it gets to hot?


Scott

 

[bwDraco]

The Panasonic spec sheet says C/2 (1675 mAh) is the maximum recommended charge rate. One cell is kept around 40% and refrigerated as a reserve battery; the other has seen light use. Both cells are less than a year old.

—DragonLord

 

[ScottJD]

I would say 1A charge would be fine then. I have 2 Panasonic 18650 cells also a few months old, I think they are the 3.8V cells and one of the reasons I got the XTAR VP2 charger for the 4.3V charging termination of those cells.
The only reason I have more Samsung cells is because it was from a HP laptop extended spare battery I never used. Both are good brands and would handle 1A with out breaking a sweat.

If you had said they were some ????fire cells that came with lights or laser pointers from ebay or Amazon then I would be worried. I've taken a few of the fake 18650 apart and each one surprised me on how bad they were made.
Trustfire makes a good protected 14500 but it's hard finding the real thing and not the fakes. I have some real ones and some AW 14500 and charge them at 0.5A


Scott

 

[psychbeat]

I've never heard of a 4.3v Panasonic cell.
R u sure?

1amp charge rate should be fine for any quality 18650.

 

[dc38]

I've never heard of a 4.3v Panasonic cell.
R u sure?

1amp charge rate should be fine for any quality 18650.

Some pannies reach full capa at 4.35 v...something like a 5-7% capa over a 4.23v charge

 

[ChrisGarrett]

Some pannies reach full capa at 4.35 v...something like a 5-7% capa over a 4.23v charge

Some Sanyos do, some Samsungs do and some LGs do, but I'm not aware of any official Panasonic (owns Sanyo, so maybe some cross-over?) data sheets showing a Panasonic branded cell that can be charged to 4.30v, or 4.35v as a rule.

I might be missing something, but I've been fiddling with 4.35v cells for a year and I'm always keeping an eye out for new developments.

Chris

 

[ScottJD]

I can't be %100 sure, I'm only going off of what I could search for with Google.
It say for sure 3.8V, ICR18650A310 and the ,arming YLE on a green wrapper rated for 3000mAh
I even unwrapped one and looked up the numbers printed on the metal cylinder and didn't find anything on it so I re-wrapped it.
They are out of a good USB power bank that had missed soldering points, but I did confirm the circuit used to charge it did charge the cell to 4.3V.
So instead of using my home made USB charger from one of the circuits I decided to get a dedicated Li-Ion charger and went for the XTAR since it was one of the few that would charge to 4.3V.

I didn't feel like hacking and reprogramming my hobby charger with a new firmware to increase my cutoff to 4.3V. It's worked good for year and I depend on it for my LyPo packs for racing and didn't want to mess up the hobby charger. But I thought about it.


Scott

 

[dekelsey61]

In all your guys options, for 18650 batteries which charge current would you get the most cycles and longest battery life out of? 500ma or 1000ma?
Thank you.
dan

 

[mattheww50]

The 500ma charge rate will probably result in marginally longer life. The reality is the device you are probably going to use the cell in will be tossed long before you run out of cycles on the battery.
300 cycles= once a week for almost 6 years

If you measured the difference in capacity after 100 cycles, you might be able to tell the difference. The applicable word is might. Even you can measure the difference (it is likely to be only a few per cent), in actual use, I doubt you would be able to tell the difference.


The net result is the difference is going to be neglible as long as you are using quality batteries like Panasonic.

 

[bwDraco]

As I said, I'm using a Nitecore battery, built around a Panasonic cell. This is a high-quality battery.

—DragonLord

 

[ScottJD]

In all your guys options, for 18650 batteries which charge current would you get the most cycles and longest battery life out of? 500ma or 1000ma?
Thank you.
dan

What mathew50 said. It's so marginal over the years most won't see or notice the difference.
Li-Ion does not build up memory like NiCad did in the past. I finally replaced my Royavac IC3 Nickel metal hydride AA/AAA batteries with Eneloop cells after 12 years of use. They are rated for 2000mAh and my tests last month show an average of 1500mAh to 1600mAh and this was after 12 years, Li-ion is supposed to be better than Nickel metal hydride as long as you properly store them when not in use for a month or longer. And my IC3 are 15min fast charge cells that got extremely hot while charging, but they were designed to take the heat.

With proper storage/usage of Li-Ion cells these batteries will outlive whatever application your using them for. If your not familiar with proper care for Li-ion then I would Google it. Basics like not over charging, having a multimeter to check and make sure you charger is not over charging. Not over discharging and draining them to the storage voltage when they are not in use. Some store them in the fridge, I never have but my Samsung specs state storage at 20C to 25C so room temperature for mine. Others may prefer colder.

As I said, I'm using a Nitecore battery, built around a Panasonic cell. This is a high-quality battery

I think matheww50 was answering Dan


Scott