I’m looking for some new 18650 batteries and the NCR18650GA seems very nice except the somewhat low charge cycles. It’s rated at 1.65A/0.99A CC/CV charge and discharge @6A to 2.5v and about a 12% drop after only 80 charge cycles. But as far as I understand charging/discharging at lower amps will increase the lifetime dramatically. Meaning it might actually be a better alternative to the panasonic NCR18650B? Or atleast comparable just with higher potential output with since the NCR18650B is rated at 0.5C charge/1C discharge which means about 1.66A/3.350A
The light in question is the noctigon m43 but also potentially any new zebralights (which seem very interesting) But also running older lights that use much less power. And I’m more interested in runtimes/recharge cycles at the moment than max output.
The big things that kill lithium batteries is temperature and more important in this case is charge and discharge levels. As in charging them to 90% instead of 100% greatly improves cycles as does discharging them to something like 90% instead of 100% capacity. To quote some examples from battery university, 100% discharge is 300-500 cycles, 50% discharge is 1200 to 1500 cycles. This already plays well for us since most lights cut out at around 2.8-3V instead of the 2.5V the batteries are rated for. On the charge side you have, again another example from battery university, 4.2V charge level 300-500 cycles and 4.1V charge level 600-1000 cycles. This is a little more difficult for us to do and of course we loose usable capacity here in exchange for cycles. This probably could be done with a charger that was a 3.6V li-ion setting instead of the now much more common 3.7V. Personally I wouldn’t worry about it, the batteries are pretty cheap compared to the lights you are running and will probably last quite a bit longer than the spec sheet due to the higher than 2.5V cutoff.
Sanyo GAs are my current favourite cells. It is very likely that they are going to be replaced in about two or three years time with a successor Sanyo cell with 3600 mAh and 15A capacity. It is very likely that the current GAs only will have a couple of dozens of charge cycles…
Practically both cells probably have similar lifetimes. If you are really interested do some searches on the endlesssphere forum, which is about electric bikes. Some people on there do lifetime testing of these cells at different charge and discharge rates.
Oh no, I mean they are probably just fine, but it is likely they will be replaced with something better. I’ve got a couple of xtar 18650B that are not doing anything for similar reasons.
I have 4x GA’s in a YZXstudio powerbank that has been heavily used in the last 6 months, it gets at least a cycle per day, discharged every time down to 2.5V and charged back up at 1.2A per cell to 4.2V. Initial capacity was 13,500mAh and after about 200+ cycles I’m still getting 12,600mAh.
Got ya I thought you meant like after 50-70 cycles or something they were done for. I usually charge my batteries at .5 to 1 amp depends on whether I use vc2 or opus 3100. But if I notice the vc2 on 4.2 in the CV stage I’ll pull it. Same on the opus when it hits 4.19 etc. Don’t always catch it not going to try lol. But if I walk by and it says that I’ll pull them. Usually says full but figure may give a few more useful cycles not being completely topped off. I’m fine with 95% battery
I suspect you are right about that since I’m considering replacing my old panasonic 2900Mah that I bought only a few years ago and they have been cycled very few times. Would make great batteries for a non flashlightaholic. Just need to figure out a way to get one of my friends to buy some old light from me and bundle it up with a charger and batteries…
If the meteor is good I might let go of my old sc600 since I mostly only use it as a light at home.
To my way of thinking cells are cheap & there to be used.
I am not really interested in whether I can get a few extra cycles out of them by “molly coddling” them during charging (or use).
My cells get charged up fully to whatever voltage my chargers charge them to then are used & recharged the same.
If I know cells will not get used for a few months they are stored at around 3.8v but I always have some fully charged cells laying around just in case.
If you look at how most lithium powered items are used, power tools, phones, laptops, tablets, lights with sealed lithium power packs etc, they are charged to the max each charge cycle & left like that between uses & the cells still last an awful long time & endure a lot of charge cycles.
Take cordless power tools, if you are not a tradesman that uses them daily do you keep them at a storage charge in between uses just charging them fully when you use them ?
I am not saying that not charging cells fully will not result in longer life/number of cycles just that it is really not that important to me.
Just my opinion of course
What you said in Post #12 ‘bella-headlight’ was very well said.
You made some very valid points about cordless tools I had never really thought about either. :+1:
I most always store them charged up waiting for the next use…. if I think about it after using them. Otherwise it is whatever state of discharge they happen to be in when I finish using them……
I have an expensive Hitachi cordless drill/driver.
It is 8 years old.
It came with 2 batteries.
The one that is not in the drill is in the drills storage case fully charged.
It may stay like that for several months before I use the drill & flatten the battery pack that is in the drill which may have been fully charged after the last time I used it or may just have whatever charge was left in it after I finished using it.
I will then put the stored battery in the drill & re-charge the flattened battery which then goes in the storage case fully charged until it is needed.
I would imagine most cordless tools are used like this ?
Likewise my Olight H35 wave headlamp has a sealed lithium battery pack.
This is stored with the battery pack fully charged as there is little point storing it only partially charged as when I grab it to use it it needs to be fully charged not have to go on charge for several hours which often I would not have the time to do.
Interesting that cordless tools were brought up. Today I got to thinking my cordless driver probably contains 4x18650 @ 1500mah since it’s a 14.4v 1.5Ah batterypack and those could probably be replaced with much better batteries for next to no money. Not that I need it but it’s fun to think about.
I always charge my cells very slowly, I figure I abuse them enough during discharge, why abuse them while charging for no reason? This is why I have a few spares, I simply toss a spare in the light and the old one on the charger at ~.5a charge rate or so. My cells don’t warm up during charging. I also undercharge them a bit, generally 4.18v is my full charge (aka, going directly in a light) and 4.11v is my “ready for service charge” (aka, going into the reserve to use at a later date).
If it is a lithium pack it would indeed. I have upgraded several tool packs over the years, the important thing to remember is that power tools need a LOT of power.
So high drain cells are a 100% must. I would use HE2’s or 30Q’s myself or if you really like the tool you could use vtc6’s.
My charger can’t even do more than 0.5a so I have no choice but it also can only do 2 batteries at a time. So I really should get a new charger while ordering the sanyo batteries.
It’s indeed a lithium pack. And yes I really like the tool, but I’ll probably wait until the packs wear out more. And I figured it’d need high drain cells. It’s a slightly older dewalt that I inherited and for my small hands it feels really good to use. Was probably bought for 200ish euro with 2x1.5Ah batterypacks so it’s definitely one of cheapest dewalts around.
Those little drills can still pull upwards of over 30 amps, so don’t skimp on the batteries. That said it is a lot cheaper to rebuild then buy new and you get better cells too boot.
