Charger overcharges my batteries

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, and others.
Is this happening on one channel only or both?
Maybe a stupid question, are you using a balance board?
Start by trimming down your Peak voltage like @Ari33 stated earlier. Try 4.1v as a start.
When you say cells are not balanced, how far off are they from each other? 4.18, 4.19, 4.17, 4.16 are all considered balanced values. If you are looking for them to be exact to the .001, then that is not a correct assumption. IMO
 
Is this happening on one channel only or both?
Maybe a stupid question, are you using a balance board?
Start by trimming down your Peak voltage like @Ari33 stated earlier. Try 4.1v as a start.
When you say cells are not balanced, how far off are they from each other? 4.18, 4.19, 4.17, 4.16 are all considered balanced values. If you are looking for them to be exact to the .001, then that is not a correct assumption. IMO
It happens on both channels. Yes , I'm using a balancing board, it's not possible to plug the balance wires straight to the charger. About the voltages, I don't sweat it if the cells are unbalanced by .02 or .03. Sometimes though the difference is bigger than that, like .08 - .1 volts. My main worry is the overcharge, if that gets sorted, the balance problems should be less of a concern
One thing I was wondering: if the batteries are often overcharged, shouldn't they get slightly swollen? I ask because mine are still pretty flat and hard, they haven't puffed yet, which is weird.
 
I have used balance boards before. They are a necessary evil at times. They work great if they are of good quality. They fail big if they are not.
Do you have a spare B board to change out. I am using a Strix JB signature edition. I rather pay more. I have been through so many cheapos. Not worth the risk. I had one board fry and smoke up my house. I was present however.
20190827_152955.jpg
 
Last edited:
I'm using the boards included with the charger, so I wouldn't know about their quality. Switching between them doesn't make a difference. Unfortunately they're the only ones I have on hand...
 
I find that some charging issues arise from failing Bal. Boards. Happened to me also. Using included Bal. Boards with my SkyRC charger years back. Just food for thought. I think that is your first priority to focus on.. The BB. Bypass the BB altogether.(y) And test. Eliminate the BB from the equation. If you haven't already. I don't use bal. boards regularly. Only
in a pinch when I need a slew of lipos pretty fast. It is rare. But I use a well known quality Bal. Board.(shown)
 
One thing I can do is try to charge just one cell of one of the batteries on the 1s setting: if it stops at 4.20 then that means the problem isn't the charger not stopping at the cut off voltage, but the balance function that somehow messes with the charge. In that case, I can get some better balancing boards and see what happens
 
I don't even use balance boards. I simply use an extension cable for the size of battery I'm using.

Amazon 3S
Amazon 4S
Amazon 6S
I have the same too(y)
One thing I can do is try to charge just one cell of one of the batteries on the 1s setting: if it stops at 4.20 then that means the problem isn't the charger not stopping at the cut off voltage, but the balance function that somehow messes with the charge. In that case, I can get some better balancing boards and see what happens
Great idea. Charge 1 cell is ok too. (without A Bal. B.) To establish if the peak value is correct. But you also have to charge the other cells at some point. Always keep # of charge cycles the same within a Pack too. Don't compromise an otherwise good Lipo Pack.
 
There is no fast charge option, only a "charge" one. There is also a "balance" option, but that only balances the cells without charging the battery. Yes, the amperage tapers off when the battery voltage rises, as is common with all chargers. The problem is, when the cells reach 4.18 - 4.19, the amperage stays around 0.2 A and it takes a long time for the cycle to finish.
That seems really odd to me. Every charger I have has a "charge", "Balance", "Discharge", "storage" feature and if I use balance, from an empty pack, it will fill it at whatever amperage I use, then trickle at the end and balance. If I just use Charge, it doesn't balance, they only detect the full dip. If the battery is full or empty, I use storage and it takes it to the storage voltage and balances.

My dynamite, hitec, HTRC, iSDT chargers all work that way. I pretty much only use balance and storage on all of them when charging my lipo's. I only use "Charge" when charging up NiMH packs/AA cells/transmitter/receiver packs.

I guess it does appear that there's a setting in the advanced menu to enable balancing for the battery type. Which doesn't make a lot of sense to me to have the "Charge" with balancing enabled and the "balance" button as well. Regardless, the manual isn't overly clear on Charge vs Balance in the main section. I'm assuming you have that turned on in the advance menu.

If you set it to storage charge, does it balance them properly then?

It’s a misconception that the charger controls the amperage. The battery will draw what it needs. The charger is only capable of setting a max output. Near the end of a battery charge, the battery needs less amperage and draws accordingly. This goes for all battery types.
Learn something new every day! With that in mind, I'm assuming a battery is kind of dumb when empty and will take in way more than it should, which is why we limit them to 1C or 2C (or more if rated to allow it), but as they fill, they smarten up electronically/chemically and only let so much current in?
 
Last edited:
There are only several software charging algorithms used in the multitude of chargers that are out there. That is why we see the similar settings. Its a charging standard created by the Lipo mfrs.
 
That seems really odd to me. Every charger I have has a "charge", "Balance", "Discharge", "storage" feature and if I use balance, from an empty pack, it will fill it at whatever amperage I use, then trickle at the end and balance. If I just use Charge, it doesn't balance, they only detect the full dip. If the battery is full or empty, I use storage and it takes it to the storage voltage and balances.

My dynamite, hitec, HTRC, iSDT chargers all work that way. I pretty much only use balance and storage on all of them when charging my lipo's. I only use "Charge" when charging up NiMH packs/AA cells/transmitter/receiver packs.

I guess it does appear that there's a setting in the advanced menu to enable balancing for the battery type. Which doesn't make a lot of sense to me to have the "Charge" with balancing enabled and the "balance" button as well. Regardless, the manual isn't overly clear on Charge vs Balance in the main section. I'm assuming you have that turned on in the advance menu.

If you set it to storage charge, does it balance them properly then?
The Advantage Touch Duo that I use has all the basic functions every battery charger has, like charge, discharge, storage, cycle... it also has a balance function that only balances the cells. Normally, the charge/discharge/storage functions all have the balance function included, but it can also be excluded by the advanced settings.
Usually, when the batteries are charged with the storage function, there doesn't seem to be any problem: all the cells are charged between 3.84 and 3.86 volts, which is good. It's only on full charge cycles (which, again, also balance the cells) that voltages of individual cells read way over the limit.
I used to have a cheap Imax b6ac (genuine) and it never gave me this kind of problem.
 
Little update: this morning I found a way to plug the balance connector of the batteries straight to the charger without the use of a balance board. The charge cycle of the first battery ended with the voltages 4.22 - 4.19 - 4.21; it's definitely better, but there's room for improvement. Is it normal for a battery to still be charged over 4.20 per cell? Can it be the result of a damaged battery at this point?
 
Little update: this morning I found a way to plug the balance connector of the batteries straight to the charger without the use of a balance board. The charge cycle of the first battery ended with the voltages 4.22 - 4.19 - 4.21; it's definitely better, but there's room for improvement. Is it normal for a battery to still be charged over 4.20 per cell? Can it be the result of a damaged battery at this point?
4.22 isn’t that bad. It’s prob gonna take a few discharge/ charge cycles to get that 4.19 cell back into shape. Your charger was trying to bring that one cell up. Your balance cycle may help, but I think using it and then charging without that balance board will help fix things.
 
Little update: this morning I found a way to plug the balance connector of the batteries straight to the charger without the use of a balance board. The charge cycle of the first battery ended with the voltages 4.22 - 4.19 - 4.21; it's definitely better, but there's room for improvement. Is it normal for a battery to still be charged over 4.20 per cell? Can it be the result of a damaged battery at this point?


Yes, in my experience thats normal. I have a few Lipos that do that when a single cells IR is a bit higher than the others.
I'd accept down to a 0.1v cell difference and would not be too concerned at discharged state.

0.03 volts difference bewteen the cells is not excessive for a used lipo. They may not have perfectly matched cell IR or perform quite well as one that did but I certainly wouldnt call it damaged.

As Jondilly says.. A few balance cycles will probably bring the lower cell back up.
 
What are your IR numbers showing you? Can you post here? At beginning and end of charge cycle.
Your IR's are a window into your cells condition.
I see that removing the Balance board helped. (y)
Most chargers wont let you go over 4.20 in Lipo mode. Or they simply should not. IMO 4.22 is an absolute max, not to be exceeded. There is never a need to charge any pack to 4.2. (4.15-4.19 is good) Hitting the max every time reduces the life of a LIpo exponentially every time you do that. 99% of charge in any lipo is really the best way to get the most life from any Lipo.
Most chargers use Passive balancing. These just bleed off the higher voltage cells through a resister while trying to directly charge/ match the lower cell to the rest. Expensive ones use "Active balancing". ( preferred ) The higher voltage cells bleed off voltage directly to the lower cells. (True balancing) Sometimes it may take numerous cycles to balance and bring the IR's close again. Normal on an older pack.
 
Last edited:
After this morning's bashing session, both batteries had a voltage of 3.66 across all the cells (but I stopped the truck before the LVC stopped it). The first battery I put in the storage cycle measured 0.8 mΩ at the end with peaks of 1.6 during charging (I forgot to take note of the initial resistance), while the second battery started at 4.0 mΩ and ended at 2.4 mΩ with peaks of 5.6. Doesn't seem too bad, it's definitely better than when using the balance board.
 
Old Thread: Hello . There have been no replies in this thread for 90 days.
Content in this thread may no longer be relevant.
Perhaps it would be better to start a new thread instead.
Back
Top