New build - Trampa eMTB | E-Toxx | MAX6 | SK3 149kv

Hi guys,

I just had my first ride today with this build.

I managed to squeeze around 4km with 10A 6S battery. I think half was uphill.

The battery died pretty quickly, even the meter shows half voltage the esc’s does not power the motors anymore. (I have another 4 x 8A 4s battery dispatched to make a 8S2P setup)

I went home to charge the battery with this charger. It took 17minutes for fast charging with 3-4A current, even the display shows 749mAh capacity charged. Isn’t this strange? Something must be wrong, is it way too fast.

Thanks @Nowind and @EssEnn for the help calibrating the ESC’s


looks nice - its a trampa build - NOT gonna be cheap, so why the cheap battery? (HINT: use Li-ion…)

I was in a hurry and I think I chose poorly. Can you recommend a good li-ion?

wait, is your voltage meter showing all your cells around 2v?

you can’t drain lipo cells below 3.2 (maybe 3.0 if you accidently push it) before ruining the battery permanently… that is probably why it only charged 700mah or so.

Yeah I dont think that is right as what @cmatson just said.

This Lipo’s should charge to 4.2V max and 3.2 Minimum. Something is not right.

I chose the same thing as you with batteries almost as I went Lipo as well although I got some Zippy flightmax’s. For me it was about price and ease to replace. I can also carry more battery packs for a longer range.

I see you are in the UK and London in fact. Fancy meeting up one day for a ride? I live in Windsor so I can come into London for a burn about hampsread heath some time! Also what app are you using to track your rides?

Whats the app called looks cool

The app is called LB MAPP and it is iOS only.

Sure do @EssEnn. Next weekend I’m not in town, but the following ones we can hang out. Hampstead Heath is just good for mounting boarding.

I’ve built a couple batteries for trampas including my own if you want to get a custom battery :slight_smile: 10s8p or 12s7p max

I can do a hug 8s pack too


not in particular, but something like this.

@ciocan great build! Like @cmatson said, if you drained your lipo cells this low you may have destroyed your battery, so proceed with caution. Does this ESC not have a low voltage alarm? It should have stopped you from going that low.

@ciocan If I’m understanding what you’re saying, you charged your 6s battery up to 22.2v (3.7v/cell) and then stopped? If so, you’ve only begun the charging process and still have a ways to go. Your batteries should be charged up to a max of 25.2v (4.2v/cell), and discharged down to about 20-21v (3.3v-3.5v/cell), at minimum, for decent battery longevity.

@ciocan the values of the voltage on the pic are too low (-2 V) that battery may be compromised already, be careful with the lipo.

Hey Dude,

nice that you got the beast running.

The used Lipos are in 1P configuration not a good choice, i know they are cheap but thats all. Now they are damaged for sure, be carefull with this pack! Would not use this anymore my friend.

If you wanna stay with Lipos i recomend this ones as 8S-2P config:

Many of my friends and me are using this Lipos for long times, just as the 6S ones.

If you wanna go with the 18650 stuff you should give @barajabali a call, heard more then one times that he is building very nice packs.

Keep on riding. Jenso

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Thanks guys for the battery tips. It was rookie mistake, I had no idea that how it worked, I had the impression that can be fully discharged. On top of that, to squeeze more juice I deactivated the low battery warning from the ESC. Then it goes directly to the battery graveyard.

Then I ordered 4 of these ZIPPY Flightmax 8000mAh 4S1P 30C.

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Ah dude, sorry to hear about the batteries. Here is another hint I figured out. When I got my batteries I first discharged them using the storage charge mode on my charger. This balanced discharged my batteries so they finished at the same voltage. I then did a full charge in balance mode so all the cells finished at 4.2v.

Also reading up on lipo’s, you should not leave them fully charged or discharged as this shortens the battery life.

@ciocan I’d love to meet up for a ride that weekend, I iist need to double check I have the Saturday free but I think I do

Finally, I build the LiIon battery back. 2 x 4s8p with a total of 8s8p, the max capacity for eZRUN MAX6.

I did not have access to a spot welder and I chose to solder with a copper wire. Total time around 4 hours. Tip: I made the copper wires a bit curvy especially between the anodes. It will be way harder or never to make a short circuit in case of overheating.

I have to say that I’m impressed. I had two runs about 30 minutes each (around 12km in total) and still had 10-12% left. At some point I wished to be empty already and go home because I started to feel exhausted.

I totally recommend the G-Form body protections. They are not cheap but they are incredible. You can wear the elbow and knee protections under your clothes and barely feel them. And I had two hard falls directly on my knees and I did not feel a thing.

One thing I wished I had is the motor mounting to have enclosures for the belt system. All the grass and dirt is stuck between the parts because of the grass carving.

And here is the short video:

I have to say, eMTB is so much fun.


Man that was fast getting the packs together! How are you charging?

How hard was it to solder the packs together? Looks like you did a pretty good job there and I might have to build a pack by spring now. I get about 20-25 minutes of ride time with 10,000Mah which is fine as I start to get tired by then but I’d like a hours ride time so I can go exploring without having battery anxiety the whole time.

If you don’t want to worry about dirt and grass then you are going to want chain drive but it is more messy and a lot noisier.

Nice. If i get it right you dont have secured the motorwires next to motors?! What i mean is that these wires coming from the Turnigys are not flexible, if they are unsecured they move too much and can be damaged. You see the massive movement in your video as well. You should ziptie them on the braces, that way that only the silicon ESC wires can move. Hope you get me right.

Yeah grass and mud is not the Beltdrive best friends.

Keep on riding Bro.