Charging Li-Ion 3.7V with iMAX B6 Pro

Hi to evbody!
I have the charger above and going to charge some 18650 cells taken out from old laptop battery pack to check the real capacity and to separate the good cells from the bad ones.
These cells are marked Li-Ion and 3.7V.
The manual of the charger recommend to set the right type of battery before to start the charging and here is the question…
For Li-Ion it set 3.6V that is lower form the nominal voltage of my cells.
For Li-Po it set right 3.7V but the type of the battery doesn’t match the chemistry of my cells.
Which one should i choose to charge properly my cells?
Thank you very much!

Li-Ion it set 3.6V >>> Full 4.1V
Li-Po it set right 3.7V >>> Full 4.2V

I set my iMAX B6 Pro to Li-Po 3.7V for charging my 18650s

Same here :slight_smile:

Welcome to BLF!

Use Lipo. There are essentially no 4.1v Li-on anymore.
You can use that setting if you want to slightly undercharge the battery, which is better for it.

Welcome to the BLF pass75.

I hope you have fun here. I know I do :-)

Charging a lithium ion cell to 4.2v reduces it’s cycle life to 300ish cycles to 80% capacity. For LiPO, it us a sacrifice you make for higher capacity. Charging a LiIon to 4.1V would increase cycle life to 800ish cycles to 80% capacity

Nice forum, I didn’t expect so many replies so quickly!
It means being 3.7V cells I can charge them using Li-Po program (wout any risk) for full capacity and the Li-Ion program for better cells lifespan. Being honest I could even notice in some recent laptops a specific function that prevents the battery to be fully charged (it stops the charge to approx 80%) right to preserve the cells lifespan.
Thank u very much to evbody!!

You are correct pass! WRT capacity tests, try charging at a lowish current , say 1A max. If you’re specifically testing capacity for use in a particular light, discharge the cell at the max current draw of that light . Expect really low capacity values for high currents. If doing a general test, a discharge current of 1A is ok. With real capacity tests, discharge is done at 0.2C I believe which for a 2000mAh cell would be 400mA, and charging is done at 0.5C or 1A for a 2000mAh cell.

Hi guys, i considering getting a iMax B6 but i wonder could this charger charge a LG D1 cell to 4.35v??


No, only to 4.2v. None of the inexpensive hobby chargers will that I know of. Some of the expensive ones will.

If you get an IMAX > BE SURE TO NOT GET IT FROM eBay cheap! There are fakes ones going around that are poor quality. Use an RC dealer that has assurance it’s real.

flydiver, thanks for the advice. What brand of hobby charger would i be able to charge my LG cell to a 4.35v? Any idea what is the price range like for those that are capable of it??


Didn’t know abt it and didn’t collect info before… My guilty… So i took a fake B6! Same as the fake box with no sticker… moreover seems it has a bug: it doesn’t stop the discharge once the cells reach the lower limit in discharging program. It’s a big problem because in case of Li-Ion discharge if the voltage of the cells goes below the safe limit they get unusable. Nice bargain i made! Anyway thanks for the advice!

Try discharging in NiXX mode and setting the lower voltage limit. That might work. The charger doesn’t care, it just does what it is set for.

That said, the fake has balance, overcharging, undercharging, and NiXX charging woes. Some are actually OK, but it doesn’t seem like the potential risk and headache is worth the few bucks you save.

First - 4.35v: why bother? You don’t get much more for the extra price and hassle.
But, if you simply must, consider a Opus BT-C3100 V2.1. Much easier to use than a hobby charger and able to do 4 cells at a time. It does have the hassle of needing to change an internal switch. There are likely other chargers that do not have this issue. I don’t use 4.35v so don’t care and don’t follow them.

The hobby chargers I’m referring to start at $100+ and you’ll need and expensive power supply additionally. Some folks here have them. I don’t, I use an Accucell-6 and an Opus. Since I got the Opus I seldom use the AC-6 for Li-on.

Bingo! U were right: using Ni-Mh discharging program and setting 3V as cut-off voltage it stops correnctly at the end of discharge.
Thank u very much for the workaround… i was almost ready to ship back the charger to the seller… Thank u!

Glad it worked. Depending on your needs and the hassle involved I’d dump that unit and get a ‘real’ IMAX, or better an Accucell-6.
Your problem indicates something wrong in function. There could be more you don’t even know about.

LiHV (4.35 cells) can be charged with a Turnigy Accucel-6 80W 10A Balancer/Charger LiHV Capable. I've seen these for sub $30usd on HobbyKing. I have zero experience with these chargers so buyer beware. As always be on the lookout for fakes. HobbyKing would be a decent source for a real one.

The Imax B6 V2 can also charge LiHV cells. As I’ve seen it stops at 4.1 V, I tried LiHV charge function but it stops at 3.98 V. Next time, I shall try LiPo charge function :slight_smile: .