Kraton 8S Dual Lipo 4S Battery Issues

[pmmiller]

Hi all, fairly new to the hobby. I recently purchased my first rc car, a kraton 8S. I've had some issues that I believe are related to my batteries and am looking for some guidance.
I am running dual gensacearespammers Bashers 4S 11000 mAh batteries. When I first got the car a couple months ago I would get 40-45 minutes of run time on my batteries. Now I'm getting about half that, around 20 minutes. This is on an easy light run, if I'm running it harder/faster in an open field or lot I'm getting only 5-7 minutes.
When I plug my batteries into my Protek Prodigy 66 charger I'm seeing that one battery is much lower than the other. I've attached some pictures but one battery is around 13.7V and the other one is 14.85V. I then run a balanced charge and they both take about the same time to charge and reach capacity and they finish right around 15V.
To me it seems like only one battery is being depleted and the car shuts down when the one battery reaches a low voltage. Both batteries are less than two months old and appear to be in good condition.
My question is what would cause only one battery to drain while running the truck? Is this an issue with the battery or something else with the motor, esc, or battery connection cables? Curious if anybody else has had this issue and what the fix was?
I appreciate any info.
Thanks!
-Paul

 

[SrC]

You pretty much got a grip on this for the most part and yeah that's a problem. I would absolutely call Gens of Ace. Great tech support having spoke with them before. I had a simlar issue. Just a few cycles and one pack was way off than the other. Bad IR's was the tell tale sign for me. Bad lipos just happen. A thing no matter the brand or even price. Maybe they will send you out another one. They did for me. And I was good with the new pack. Like night and day.
I would check and compare the Internal resisiance of all the cells for bth packs, They should be all very close to each other. And what area all the cells voltage readings when LVC happens this way?
Need to have a lipo testor out in the field when this happens and get Quick reads off the Lipo balance leads of both lipos to hone in on the bad cell(s). When the cells rest even for a minute, volts all come back again, and can be misleading.
Storage charging them right after use, as well as running them with a few hours of being fully charged makes them perform best. Will also last way longer. Let a pack cool down before storage charging them. Maybe you already know this? IDK.
And always charge at a 1C rate. Which would be 11 amps with tose packs. I know they are very expensive. Do call Gens of Ace First thing.
Good luck.
Happy Fathers Day.

 

[Moirae]

The lipo that drains faster is definitely struggling in the ir department compared to the other one. As src said you need to make sure you are practicing good lipo maintenance as the ir of each cell will gradually get worse if you leave a lipo at full charge or drain em to low.

 

[Surchaufeur]

Hi all, fairly new to the hobby. I recently purchased my first rc car, a kraton 8S. I've had some issues that I believe are related to my batteries and am looking for some guidance.
I am running dual gensacearespammers Bashers 4S 11000 mAh batteries. When I first got the car a couple months ago I would get 40-45 minutes of run time on my batteries. Now I'm getting about half that, around 20 minutes. This is on an easy light run, if I'm running it harder/faster in an open field or lot I'm getting only 5-7 minutes.
When I plug my batteries into my Protek Prodigy 66 charger I'm seeing that one battery is much lower than the other. I've attached some pictures but one battery is around 13.7V and the other one is 14.85V. I then run a balanced charge and they both take about the same time to charge and reach capacity and they finish right around 15V.
To me it seems like only one battery is being depleted and the car shuts down when the one battery reaches a low voltage. Both batteries are less than two months old and appear to be in good condition.
My question is what would cause only one battery to drain while running the truck? Is this an issue with the battery or something else with the motor, esc, or battery connection cables? Curious if anybody else has had this issue and what the fix was?
I appreciate any info.
Thanks!
-Paul

View attachment 306596

View attachment 306601

When you say a balance charge around 15v. Do you mean storage charge? Because that is not a fully charged 4s lipo. A fully charged 4s is 16.8v total. Bad lipos happen. Can you look into the internal resistance with ur charger? That can give you an idea of whats going on. A higher Internal resistance cause higher voltage sag under load and lower run time, more heat generated that is how lipo end up puffing Temporary and permanently

 

[pmmiller]

When you say a balance charge around 15v. Do you mean storage charge? Because that is not a fully charged 4s lipo. A fully charged 4s is 16.8v total. Bad lipos happen. Can you look into the internal resistance with ur charger? That can give you an idea of whats going on. A higher Internal resistance cause higher voltage sag under load and lower run time, more heat generated that is how lipo end up puffing Temporary and permanently

I'm glad you chimed in. My batteries were charging to around 15v. After reading your comment I went through my charger settings and found a capacity limit of 5000mAh. Not nearly enough to charge these 11000mAh Bashers. I turned this capacity limit off and I was able to charge the batteries fully. I'm working on a couple other repairs at the moment so am not able to do a run test, but I think you helped solve my problem. Thank you

You pretty much got a grip on this for the most part and yeah that's a problem. I would absolutely call Gens of Ace. Great tech support having spoke with them before. I had a simlar issue. Just a few cycles and one pack was way off than the other. Bad IR's was the tell tale sign for me. Bad lipos just happen. A thing no matter the brand or even price. Maybe they will send you out another one. They did for me. And I was good with the new pack. Like night and day.
I would check and compare the Internal resisiance of all the cells for bth packs, They should be all very close to each other. And what area all the cells voltage readings when LVC happens this way?
Need to have a lipo testor out in the field when this happens and get Quick reads off the Lipo balance leads of both lipos to hone in on the bad cell(s). When the cells rest even for a minute, volts all come back again, and can be misleading.
Storage charging them right after use, as well as running them with a few hours of being fully charged makes them perform best. Will also last way longer. Let a pack cool down before storage charging them. Maybe you already know this? IDK.
And always charge at a 1C rate. Which would be 11 amps with tose packs. I know they are very expensive. Do call Gens of Ace First thing.
Good luck.
Happy Fathers Day.

Thanks for the info, much appreciated!

 

[Surchaufeur]

I'm glad you chimed in. My batteries were charging to around 15v. After reading your comment I went through my charger settings and found a capacity limit of 5000mAh. Not nearly enough to charge these 11000mAh Bashers. I turned this capacity limit off and I was able to charge the batteries fully. I'm working on a couple other repairs at the moment so am not able to do a run test, but I think you helped solve my problem. Thank you

Thanks for the info, much appreciated!

Ur run time will drasticly increased. Hope ur lipos didnt get damaged with that voltage difference