Talion Decreasing Runtimes

Honestly, its probably the batteries. Are they 2S, or 3S batteries? Did the last person have them in storage before you bought them? 15 min is a short run time as it is. you should be getting close to double that even driving aggressively. I can get 40+ min out of my 4S Vant battery, and 35 min on a SMC 6S driving like a fool in the Talion. Batteries are fickle, and getting the right charger for them is important as well. I learned the hard way.....
https://www.amazon.com/5200mAh-50C-...=UTF8&qid=1529406160&sr=8-25&keywords=4s+lipo

That's a cheap 4S that I have that works quite well.

In addition to @ThatDrewGuy, have you checked each cells voltage @TalionRunner? Have you done a balance charge as well?

Does your charger tell you how many Mah it is putting into the batteries? Also, can you charger do a charge/discharge cycle, and tell you how much it put in / took out? This can tell you if you have a battery issue.

The on the truck - is it rolling free? do you have a bad bearing or three? diff binding? Wheels full of water or dirt?

Hey all and thanks for the reply’s, they are 3s, and I’m using a dynamite prophet sport charger, 35v and charging at 3ah. Perhaps it’s the charger? (My fault for going cheap)

Yeah, I had the 2 channel version of that charger. It got the job done for a while, till it didn't... LOL

So step 1 is finding out if your battery is actually properly charged straight off the charger, and how close the cells are in voltage when the run is over. If you have a multi-meter, you can check the pack voltage across the main lead to see total voltage, and across the balance lead to see cell voltage. Easier, is to get a lipo checker. I have two at the house-
https://www.amazon.com/gp/product/B01JOO3H5M/ref=oh_aui_detailpage_o08_s00?ie=UTF8&psc=1
This one from amazon is new to me - purchased a few months ago when I lost the one below..(Then I found it before this one came in... LOL). Gives a lot of info, but you have to hit the 'cell' button to get it to show the cell voltage. Works. Also beeps when you plug it in, which I find annoying.

I also have this one from Hobbyking -
https://hobbyking.com/en_us/turnigy-dlux-lipo-battery-cell-display-and-balancer-2s-6s.html
I like this one better - cell voltage of all cells and % total charge displayed at the same time, but no other info. Also, this one is dead, after 2 years of use. I liked it enough that I plan on adding another to my cart on my next hobbyking order.

Once you know that (A) your batteries are properly charged, and (b) you don't have a bad cell, then we can move on to troubleshooting other things...

Had another run tonight, only 6.5 minutes, I did notice when I plug the 2nd battery in, it sparks, could that be the reason?

I

TalionRunner said:

Had another run tonight, only 6.5 minutes, I did notice when I plug the 2nd battery in, it sparks, could that be the reason?

Click to expand...

I don't think so as that also happens to mine.

Yeah, normal. When you go 6s, it is a pretty big pop! LOL

Also check your drivetrain for binding like the inner rear hub bearings. The get stuck very fast and will cause a lot of friction. 6.5 minutes is not ok!

You might have been wearing out the batteries if you run to LVC every time where the car cuts out due to low battery. The LVC is set a bit too low so if you keep doing that it will likely shorten the batteries' overall life.

I did a post run voltage test and they’re 3.4 volts? Could that be the reason it’s still running at 6.5? I also noticed the rear diff is super hot whereas the others aren’t.

The ESC capacitors cause the spark (they bleed off when the power is disconnected). The spark is from the immediate high current flow into them when reconnecting. The larger the cap or the higher the voltage, will result in a bigger spark.

TalionRunner said:

I did a post run voltage test and they’re 3.4 volts? Could that be the reason it’s still running at 6.5? I also noticed the rear diff is super hot whereas the others aren’t.

Click to expand...

3.4 volts per cell is low voltage cuttoff which is where it is set from the factory. What are your pre run voltage readings?

Rear diff should not get hot. You might have a bad bearing(s) somewhere.

A bit of 2 cents from another thread. It’s a pain but I believe you have to track your batteries. Start voltage/ or ending voltage. Do they balance. % left in battery at end and how much charger puts into the battery. This being said. I’m tracking 8 batteries and they all end at about 3.68 to 3.8 volts
no lower. Reaction dynamite 3S 5000mah 50C batteries.
Jim

This is an older thread, but I noticed someone mentioned that 15 minutes was short, but on average I get 17 minutes with my hrb 2x3S 5000mah 50C packs at the grass bmx track with my outcast and erbe. Less if I'm doing a excess wot runs for a long distance.

Glad to hear from you. The more I run the more it seems that it’s so dependent on exactly how you
Run
Where you run
Batteries
Friction in drive train
Etc.
but what I am experiencing and I don’t have enough data yet to say it’s statistically valid.
but I believe 2C charging gives better run times.
Will be back with more data soon
Jim

authorjim said:

Glad to hear from you. The more I run the more it seems that it’s so dependent on exactly how you
Run
Where you run
Batteries
Friction in drive train
Etc.
but what I am experiencing and I don’t have enough data yet to say it’s statistically valid.
but I believe 2C charging gives better run times.
Will be back with more data soon
Jim

Click to expand...

Charge rate has zero effect on run times. Do not charge at 2c unless the battery states it is capable of 2c charge rate, even then I wouldn't do it.

Hello, the batteries state clearly 3C charging okay. I have done a lot of asking of other people and most say it’s no problem especially if battery states it.
on the surface 2C charging is just putting more energy into battery faster. Can’t argue there. But I believe the internal chemistry of these batteries is affected differently with higher currents. I will see when my tests are all done. Which of course won’t prove it. ———lol. Thanks for your thoughts.

I only ever charge my packs at 1c, hugely increases longevity.