Battery Consistency Question

wisceaux

Member
Messages
42
Reaction score
10
Arrma RC's
BigRock 4x4
I have a BRCC. I have had the ESC firmware updated by HH to correct the misconfigured LVC that plagues so many BLX100s, so that is not a factor here. If I go full out, a speed run kind of pass and it goes into limp mode (when the battery is at roughly 50% let’s say) I’ve learned that this can mean the battery is dipping down into LVC range. My question is this: which characteristic of LiPo batteries should I look at improving to avoid this from happening? Is this a C rating thing? Do I need higher C? I’m not well versed in things like internal resistance and stuff. Is it something there? Or is this just a quality of battery situation? I have one Ovonic and one Goldbat. Both are 5000mAh and 50c. Do I just need “better” batteries to achieve more consistent performance? Thanks!
 

clos85

Active Member
Messages
3
Reaction score
0
Location
San Diego, CA
Arrma RC's
Granite, Senton, Typhon 3s
I have a BRCC. I have had the ESC firmware updated by HH to correct the misconfigured LVC that plagues so many BLX100s, so that is not a factor here. If I go full out, a speed run kind of pass and it goes into limp mode (when the battery is at roughly 50% let’s say) I’ve learned that this can mean the battery is dipping down into LVC range. My question is this: which characteristic of LiPo batteries should I look at improving to avoid this from happening? Is this a C rating thing? Do I need higher C? I’m not well versed in things like internal resistance and stuff. Is it something there? Or is this just a quality of battery situation? I have one Ovonic and one Goldbat. Both are 5000mAh and 50c. Do I just need “better” batteries to achieve more consistent performance? Thanks!
I don't know if this helps, but I have a Granite 3s, Typhon 3s, Senton 3s, and a Typhon 6s from Arrma. I run some of the cheaper batteries that you can order off of amazon (zee and ovonic). I ran into the same issue when I was using the Typhon 3s on 3s and 2s. The one thing that I changed on the buggy was the pinion size. I went from stock (think it was 14t) to 20t. I found that if I didn't punch the trigger I could avoid the LVC. I switched back to the stock pinion and the LVC issue went away. My experience was with the following batteries:

Zeee 7.4V 50C 5200mAh 2S
Zeee 11.1V 80C 5200mAh 3S
Zeee 11.1V 80C 6000mAh 3S
Ovonic 11.1V 50C 7600mAh 3S
 

jkflow

Well-Known Member
Messages
995
Reaction score
1,062
Location
Tampa, FL
Arrma RC's
Kraton 6s, Talion
Just responded to a similar thread, are you sure you are going into LVC or is your ESC going into thermal shutdown?
The latter would explain why you have 50% battery left. If both packs are doing the same at roughly the same time in your run, it's thermal shutdown.
Just don't tell me that it's cold in your area ;)

How are you determining that it's 50%? Do you have a lipo checker in the field?
 

clos85

Active Member
Messages
3
Reaction score
0
Location
San Diego, CA
Arrma RC's
Granite, Senton, Typhon 3s
Just responded to a similar thread, are you sure you are going into LVC or is your ESC going into thermal shutdown?
The latter would explain why you have 50% battery left. If both packs are doing the same at roughly the same time in your run, it's thermal shutdown.
Just don't tell me that it's cold in your area ;)

How are you determining that it's 50%? Do you have a lipo checker in the field?
I'm in escondido, ca. It gets warm here. Some days were high 70s and others were mid to high 80s. I do have a lipo checker and a laser temp reader that I take with me when I go out. When I was having the issue I could make it happen after about 5 minutes of running. Temp on the motor would be around 120-130 degrees. I didn't check the temp of the esc but I usually had 65-70% of battery life left when it would happen. I learned that I could turn it off and disconnect the battery, reconnect it right away, turn it back on and it would run fine until I started smashing the trigger on the transmitter. If I set the transmitter to 50% or 75% I wouldn't run into the issue. To me it seemed like a draw issue from the batteries than a thermal issue, but when I changed the pinion back to the stock one, the issue went away for good. Knowing how the C rating on batteries are usually inaccurate, I gave up on trying to push it. If I want to have general fun, I run the typhon 3s, if I want to go fast I run 6s on the typhon 6s. If you want me to test something let me know. Maybe we can figure something out.
 

jkflow

Well-Known Member
Messages
995
Reaction score
1,062
Location
Tampa, FL
Arrma RC's
Kraton 6s, Talion
70-80F is winter for me ;)

What pinion are you using?
You might be simply asking too much, these are cheap batteries and yes C is always overstated. Current Ovonics test at ~ 20-25C after the initial use which is a lot better at 30-35C. That is on par with other more expensive brands i.e. nothing surprising. C rating is not your issue though.

If your charger can't tell you the IR, next upgrade down the road should be a charger that has that function.
You could get an SMC lipo checker and leave it connected while running, any other lipo checker will do as well.
Set it to 3.7V and if it beeps after 5 min you know for sure that you have a battery issue.
 

wisceaux

Member
Messages
42
Reaction score
10
Arrma RC's
BigRock 4x4
My charger can provide IR. What does IR tell me though? What’s a good number vs a bad number?
 

jkflow

Well-Known Member
Messages
995
Reaction score
1,062
Location
Tampa, FL
Arrma RC's
Kraton 6s, Talion
They should all be roughly the same across cells. The highest number is the weakest cell. Internal resistance determines voltage drop under load and limits max current. They should be in the 2.5mOhm ranges for 5000mAh. They vary by vendor but not much. If they are all within 10-20% of each other they are ok. My guess is that one is double.
 

Create an account or login to comment

You must be a member in order to leave a comment

Create account

Create an account on our community. It's easy!

Log in

Already have an account? Log in here.

Thread starter Similar threads Forum Replies Date
Rip King MC Battery question Electronics 11
jeepnut Kraton What size battery do you run? Arrma 6s BLX 7
Coops Notorious Battery strap, have I lost my mind... Arrma 6s BLX 11
chargh Granite Fury Battery ? Discontinued Models 2
Similar threads




Top