I’m running the same kit at the moment and it’s pretty awesome.
Now the charger I am using currently measures 8.39V on the multimeter. These new chargers that have arrived read 8.48v, 8.48v, 8.51v, 8.51v when I plug them into the power outlet and measure the output using the multimeter.
If I plug the charger into the battery case, and measure the output inside the terminals which will touch the batteries the output is the same.
So my question is, is this voltage ok, am I measuring it wrong? Will the batteries deal ok with 4.24V and 4.255V or do I risk battery explosion. The batteries are meant to be protected, so just not sure.
I’ve tried googling and that is how I came across this site, but couldn’t find exactly what I was after.
I’m not getting your question with the 8V+ numbers but it reads like after charging the cells are higher then 4,19-4,21V
There are cells rated for higher voltage so they would get max charging cycles.
Looks OK to me providing the multimeter readings are accurate & the charger works correctly for charging Li-Ions (how does it charge & how & when does it terminate).
4.24 –4.255 is really the max you want to be charging the cells at but that voltage shouldn”t cause any problems other than it may reduce the number of life cycles of the cells a little.
What would concern me most is the way the charger actually works.
Just bear in mind that the 4 cells have a combined ma when in 2S2P configuration of 6,800ma & the charger delivers 1000ma so if you fully deplete the cells then charging will be a slow process taking approximately 7 hours.
I think that I have got the above right ?
If it were me I would take advantage of the very good deals available on the Liitokala Lii-500 Engineer 4 bay analsying charger that are available at the moment, about $12 dollars without a power supply or around $20 with a power supply.
This will charge the 4 cells at up to 1A each so can charge the 4 cells from flat to full in approximately 3.5 hours (1A charge rate on those cells is only .34C which is absolutely fine), also it uses the correct charging & termination for the cells where as who knows what that charger you linked to does.
Also being an analysing charger you can check capacity & resistance of your cells to track their health.
I always remove cells from battery packs, power banks etc to charge in a proper charger rather than trust some very cheap Chinese no brand type of charger
Interesting choice on the Liitokala, I haven’t heard of those before. The slow charging isn’t really an issue, getting the batteries in and out of the battery pack is really the biggest pain in the butt. It means taking it off the bike, opening charger, putting batteries in charger, charging then putting them back in the pack, putting it back on the bike. Quite a hassle.
It sounds like the 8.51V charger is probably going to be a little too close / exceed the specs, so I think I might complain back to Aliexpress and see if they can replace it for me.
I have a fair bit of faith in the multimeter readings, it reads the charger I’ve been using for my existing setup at 8.39V
I’ll only use the cheap charger while I’m awake, there won’t be any overnight charging. I’ll run a few cycles through the batteries and see how they go.
Is there any chance if you run a few power cycles through that the charger will eventually do something different, or is that very unlikely?
Also where do you get the Liitokala chargers from?
Thanks guys btw, you’ve been really helpful so far. I do love forums, always a wealth of knowledge!
If those really ARE protected cells, and the protection is decent, then that should deal with the possible overcharge issue.
In order to charge to cells to full, you do have to have at least a tiny bit of over charge. Charge them up. pull them, check them, see how they actually turn out.
FWIW, the case does not look like it has any protection, and it certainly will NOT have any balancing. So, you are going to want to pull the cells once in awhile and charge them individually to make sure they are balanced. An analyzing charger is definitely something that you will appreciate going forward.
So I pulled them last night and measured them with my multimeter. They had a reading of 4.15 and 4.16v across each of the 4 cells.
I actually own an XTAR VC4 which is pretty awesome but as these light kits are going to other people, they will just get the cheap charger. I’ll charge the cells before I give them to them so they are all at the same voltage which should make their charge/discharge pretty unified hopefully.
The protected cells should hopefully stop anything else untoward happening
