Kraton 8S EXB Going Into Low-Power Mode at Full Throttle

[Mohelind]

I have recently purchased the Kraton 8S EXB, it is still completely bone stock; no parts, no tuning, just out of the box.

I noticed this on one of its first runs, while doing a pull just matted at full throttle it will cut out and go into low-power mode, I actually didn't know how charged the batteries were so I just assumed they were low, plugging them in they were actually at 60%.

I took it out again today and once again it did this, but it let me get quite a few pulls in before it did it (it did let me get a few pulls in last time too). If you turn it off and back on again it goes back to 100% power but the second you do a hard pull it goes back to low power mode. An interesting fact was it would not go into low power mode if you slowly brought it up to max speed.

INFORMATION:
- Stock Kraton 8S EXB
- No tuning (I believe the default punch is 4/10)
- Running 2x gens-ace-r-spam 4S 8000mah 100C batteries
(I will admit the batteries have well over 10 good runs on them)

 

[SrC]

By merely restarting the ESC you just are resetting the LVC. Then it happens again.
Your lipos are basically very low at 60%, And depending on your lipo type, quality, capacity, and C Rate, LVC can cut in like this.
I bet you never checked any of your ESC settings.. specifically your LVC setting.... Right? Open the manual and look it all over. And you never stated what exact lipos you are running.
BTW, don't expect much run time with the K8s in general. It's quite heavy at 30+pounds.
How long were your run times when it went to LVC?
Some lipo packs are not all that and offer very short Run times. Is what it is. Especially 5k mah 4s packs.

 

[Mohelind]

By merely restarting the ESC you just are resetting the LVC. Then it happens again.
Your lipos are basically very low at 60%, And depending on your lipo type, quality, capacity, and C Rate, LVC can cut in like this.
I bet you never checked any of your ESC settings.. specifically your LVC setting.... Right? Open the manual and look it all over. And you never stated what exact lipos you are running.
BTW, don't expect much run time with the K8s in general. It's quite heavy at 30+pounds.
How long were your run times when it went to LVC?
Some lipo packs are not all that and offer very short Run times. Is what it is. Especially 5k mah 4s packs.

Well they are gensacearespammers Bashing 8000mah 100c 4S batteries. I have not at all looked at the LVC in the manual. I will do that.

It seemed to go for about 15-20 minutes until having an issue.

I have the first gen Outcast 8s and it would do fine on the same batteries, granted when I bought the Outcast I got two batteries just for it and the Kraton is just using those same batteries that have a few runs on them.

 

[KnowAir]

What connectors are you using? What have you used those batteries in before?

 

[SrC]

Well they are gensacearespammers Bashing 8000mah 100c 4S batteries. I have not at all looked at the LVC in the manual. I will do that.

It seemed to go for about 15-20 minutes until having an issue.

I have the first gen Outcast 8s and it would do fine on the same batteries, granted when I bought the Outcast I got two batteries just for it and the Kraton is just using those same batteries that have a few runs on them.

15 min is quite good actually, count your blessings. Seems LVC just cuts in where it should. I believe it is adjustable anyway. Check the ESC LVC setting. If your packs check out good, Great IR #'s etc and balances fine. The packs are good , this is normal.
I'm sure you know to always storage charge your lipo's right away after running them??? Just asking.
Need to be religious about that. Just one time a pack that is around less than 50% charged sitting around for days on end or even a Full charged one sitting around for days , ruins a packs capacity. Not reversible.


50% charged is roughly 3.8v/cell. LVC at about 3.5-3.6v is allowable. Eeeeking out a bit more run time. Just the higher the LVC cutoff voltage is , the more life you get out of the lipo over its whole lifecycle. If you are not getting "Limp mode" LVC first (running at 50% power), then you may have a bad few cells in the bunch. So it just does an LVC hard cut before anything.

Edit.

 

[KnowAir]

Yes, sorry I missed the 15-20 minutes statement. That's about it I'd guess before hitting LVC.

 

[Mohelind]

I have taken extremely poor care of my batteries until recently. These batteries specifically have had good care.

I just really didn't expect this short of a run time even with it's weight and power demands.

What connectors are you using? What have you used those batteries in before?

They have only been used in the Outcast 8S, and I only use IC5 in both of those, no adapters.

 

[CrashBoom]

15-20 minutes is pretty good for 8000mah batteries. When you quickly go full throttle you put a load on the battery which causes voltage sag. When you take that load away, voltage goes back up.

 

[Mohelind]

15-20 minutes is pretty good for 8000mah batteries. When you quickly go full throttle you put a load on the battery which causes voltage sag. When you take that load away, voltage goes back up.

Damn well I guess I'm just not very used to the 8S, I've had a Mojave 6S and Fireteam 6S for a while now and they pretty much always get 40 minutes to an hour of run time. Same battery type, except two 3Ss instead of 4S.

Is there a better battery pair for the K8S than G e n s A c e Bashing Batteries?

 

[SrC]

Ace of Gens Basher line is quite popular. I like the brand and have had like 4 or 5 years past. I think I have 2 rather old 4s Gens packs remaining. And they are still great, considering. Higher IR's all around, but all the cells are balanced and consistent. Def. run like worn packs however. Not cheap.. But there are a few other good brands out there. I never ventured over 6200mah packs myself with my 6s stuff.
I always found with Lipo's, no matter what, how good you treat them, you can see them peter out after about 50 cycles in. Shouldn't be that way. Just an observation. Any lipo.
The High amp draw, normally bashing hard with them, is what does them in.

 

[CrashBoom]

Is there a better battery pair for the K8S than G e n s A c e Bashing Batteries?

SMC makes good batteries. I have a couple sets, I would consider them the best of what I have.

I haven't ran Gen's Ace but they seem to be well liked so it's probably a wash.

I've had a Mojave 6S and Fireteam 6S for a while now and they pretty much always get 40 minutes to an hour of run time.

It's good to take a break and let things cool down, especially with these big, heavy trucks.

 

[KnowAir]

I think the runtime you're seeing seems about right. Only way to really get more runtime is more amp hours. Which comes with its own setbacks. More weight. Many run 9500 to 10k. Up to you but, I feel 20 minutes is plenty, and as @CrashBoom said, give it a rest. Enjoy!!

 

[CrashBoom]

Only way to really get more runtime is more amp hours. Which comes with its own setbacks. More weight.

That's a good point as well. I use lighter 6000mah batteries for more big air stuff, otherwise 8200mah.

 

[KnowAir]

That's a good point as well. I use lighter 6000mah batteries for more big air stuff, otherwise 8200mah.

I like my rigs more "sporty", so lighter packs work well for me. To each their own of course. Once we get up into 8500 or higher, really gotta pay attention to the battery dimensions too. Sucks to buy some big ole mega batteries only to find out they won't fit the trays..

 

[SrC]

Yeah with the 6s line it's hard to find higher capacity packs that will fit. I wish they would revamp the 6s lipo tray, it's getting old. The current one is only the second revision of that lipo tray from Arrma since like 2009. RC packs have become much larger capacity since then. But Like stated above, 15-20 run times with most any rig, is about average. I don't get too greedy with run time.
If looking for an hour run time give or take, you aren't that familiar with these lipo platforms. Not realistic IMHO.
The 8s lipo trays can handle larger lipos way easier. Same with the 6s Lim,Infr/Fel. FWIW. But Larger is always heavier, sometimes adding almost 2 more pounds. With that comes more amp draw, heat and less durability. A clear tradeoff. Handling can go out the window as well.

 

[KnowAir]

Yeah with the 6s line it's hard to find higher capacity packs that will fit. I wish they would revamp the 6s lipo tray, it's getting old. The current one is only the second revision of that lipo tray from Arrma since like 2009. RC packs have become much larger capacity since then. But Like stated above, 15-20 run times with most any rig, is about average. I don't get too greedy with run time.
If looking for an hour run time give or take, you aren't that familiar with these lipo platforms. Not realistic IMHO.
The 8s lipo trays can handle larger lipos way easier. Same with the 6s Lim,Infr/Fel. FWIW. But Larger is always heavier, sometimes adding almost 2 more pounds. With that comes more amp draw, heat and less durability. A clear tradeoff. Handling can go out the window as well.

Perhaps a laid down servo mount with radio compartment on top in the 6s? Similar to the 8s setup.That would cut down esc footage though.. I'm pretty content with 5-6ah batts for my 6s rigs, which the current Arrma 6s tray holds nicely. I do wonder why they didn't use the same styled trays in the 8s rigs? I have more gripes with the 8s trays than the 6s myself..the new straps Arrma is using with the oversized buckle is a PIA to work with I feel. I don't need the molded in cable holders, stuff the cables under the straps and done?