4s battery question.
 

Hello all,

just getting into 1/8 scale off road racing. I bought 2 exact 4s lipos. I purchased these brand new. I went racing Sunday and decided to run 2 classes.

pack one
Took 1 hour 46 mins to charge.
I ran my race 6 mins
I then recharged the battery for round 2
I ran my 2nd race 6 mins
i packed up and went home
when I got home I put it in storage mode which took 1 hour 17 mins.

pack two
Took 22mins to charge.
I ran my race 6 mins
I then recharged the battery for round 2
I ran my 2nd race 6 mins
i packed up and went home
when I got home I put it in storage mode which took 16 mins

charging with an icharger 406duo. Charged at 10amps. Set charger to charge to 4.2v per cell. I set storage at 3.8v per cell. All ir and volts are very similar on both packs.

any and all help is appreciated.

How closely did you monitor it? I am curious if it didn't ramp up to the full 10 amps or if it took a long time balancing it. I have had some batteries just have a bad attitude about balancing. They will charge fine (in the correct amount of time), then sit there and balance back and forth for like 20+ min. A full charge / discharge / full charge (or two) will normally sort them out. If on the other hand the charger doesn't want to go up to the full 10 amps, I would be concerned something is wrong with the battery.

It charged pretty fast it was the balancing that took for ever like you said.

With my 406duo I always charge my 4S-6.5Ah packs at 20A and depending on depth of discharge it usually takes 15-20 min to get them topped off. I always check the IR of the cells at the end of each charge cycle to make sure the cells are close to 1 mΩ ... I get nervous when any of the cells are farther than 1mΩ apart and I downgrade a pack to a practice pack when any individual cell goes above 7mΩ... I discard the pack when any cell goes above 15mΩ as a personal preference.

so it shouldn’t cause an issue charging at 20 Amps

Generally, most budget brands of batteries will recommend their packs to be charged at 1C or 1 times the capacity of the pack... so a 6.5Ah pack can be safely charged at 6.5A

Since I'm charging my packs at 20A, that works out to 20/6.5 = 3C which is what my packs are rated for by the manufacturer.

Clean the batteries balance plug with isopropyl alcohol.

I charge at 30a.