6s2p battery capcity question LGHG2

So this is my first 18650 build and i got my cells from imr batteries.

I built two 6s2p packs. The cells came in at 3.51v char51 showed at 4%

My charger is showing only about 4000mah going in to fully charge a pack Shouldnt it be closer to 6000mah?

Dunno if these are nmc type but try to discharge till 3.4 or 3.2v then charge and check what capacity u get :wink:

I assume 250mah ‘lost’ per cell.

Extra 50-100mah per cell if u charge till 4.2v

Then another 100-200mah below 3,5v

Nice charger! I got the same one!

1 Like

Nice thanks.

Im used to lipos that never go below 3.75v

So i should always run these to 3.2v in the future?

Whats the best way to extend their durability and capacity?

My lipos are stored at 3.75v so im not sure what to do with these.

Check graphs. Search lg2 discharge test

Not close to pc. Cannot help :slight_smile: Some li ions can be taken till 2,5v but personally i think below 3.0v they are not usable much.

Would recommend 3.3-3.4v as lowest discharge and 4.1 - 4.15v charge

Btw how u managed to get percentage display for reaktor? Mine does not show this in default…

https://www.e-cigarette-forum.com/forum/threads/lg-hg2-20a-3000mah-18650-bench-retest-results-a-great-20a-battery.714112/

1 Like

Check the mah cutoff in your charger’s settings

1 Like

Mine doesn show percentage. I got the percentage by using a handheld balance charge digital meter.

Its not the cut off limit but thanks. Ill cycle them several times hopefully it improves.

Oh, I remember now. Your charge is showing how much it put in the battery to bring it to full charge, not what the total capacity is. My hobby charger does the same thing. The amount it shows at end of charge will vary depending on how low the cells where before charging. It’s been a while since I used my hobby charger.

2 Likes

Liions run down to 2.5v/cell unlike lipos. You should set your lv soft at 3.0 at cutoff at 2.8. To prolong life also dont charge above 4.1v.

Your charger has a profile for LiPo and Li-Ion. They are not the same. The low voltage cutoff is different. If youre only discharging to 3.3V then you’re wasting a good 30ish percent capacity.

Storage for Li-ions is 3.55V. 50% is 3.6V

E: Discharge profile

1 Like

Hey thanks! Thats good info, i would never think they would go that low.

When you say lv soft at 3.0 and cutoff at 2.8v are your talking about the BLDC settings or the charger?

I only use my charger to charge i dont use it to discharge.

He’s taking about BLDC settings on the first page under Voltage Limits Battery Cutoff Start 3.0 Battery Cutoff End 2.8

1 Like

Report back once you charge your cells again!

Yes, my turnigy reaktor also does not show percentage… it was a nice feature which accucel 8 charger had :slight_smile:

1 Like

I will modify them this is where they are at now.

Took them down to 3.1v and the latest charge filled them 5650mah at 4.2v

I think that’s pretty good. Any thoughts?

Your charge is showing how much it put in the battery not what the total capacity is.

@Namasaki what you man with total capacity then? Do you discharge your cells completely till zero so they dont give up any more power?

Or you just meant that the discharge capacity is not the same as charge capacity?


@ralphy I think it is pretty good… this way u should now know that below 3.1v there are the rest of the capacity more or less… which would be around 350/2 = 175mah per cell or so right?

What I mean is that a typical hobby charger like the one I have, does not display a battery’s total capacity at the end of charging. Instead, it displays how much was added to bring the battery to full charge. Example: If your battery’s capacity is 6000mah and it is at 50% charge when you recharge it, your charger will display 3000mah. This is why @ralphy battery displayed a higher number after discharging his pack lower before charging it to full again. Unless he discharges his batteries to 0% which I think is something like 2.8v per cell, it is not going to display a full 6000mah no matter how many charge cycles you put it through.

@Namasaki well that is quite logical, indeed… I just thought you had some more things to add to this… :smiley:

Like, maybe, the ‘‘losses’’ or extra capacity which might be added to bring all the cells to the same level… though I havent really looked into it, does it really makes a big difference to the mah rating the charger shows

i was reading that when you speed charge you can jump up quickly to maybe 80 percent of full capacity and all is well but if you attempt to speed charge to full charge, even though the charger will cut off after a shorter time and the voltage maybe have been up to 4.2, the lithium chemistry needs the longer time to absorb the energy and it will drop to a lower voltage. A better way to say it maybe: the voltage will rise quickly with a speed charge which is misleading as the ah put in it will be less and after the cell is pulled from the power source it will decrease more than if it had been put on the charger with a slow charge to full

When you say speed charge, do you mean 5a charge or higher?