Traxxas battery pack issues continued

[truggy83]

My Jato functions properly with the 4 AA batteries installed in the rear battery box. When I put in the 5 cell Traxxas flat pack, the throttle servo jerks back and forth when I hold it at full throttle or at brake. The battery pack is fully charged and the problem stops when I install the 4 AA battery holder and batteries. I replaced the flat pack with a brand new traxxas flat pack 5 cell of the same type. I trickled chargered the battery for 12 hours and it still does the same thing as the other battery? I don't see how it could be a wiring issue as the 4AA battery holder hooks into the exact same wiring the flat pack does. Also when I install a 5 cell hump pack out of another vehicle, the truck works just fine. Any ideas why it does this and why it only happens with the flat pack from traxxas? Here is a video of what the car does when I hold it at full throttle or full brake.

 

[olds97_lss]

To me, it almost looks like your pack isn't charged up or you have a dead cell in it causing issues.

I've never ran a traxxas flat pack. Any ones I had were a different brand.

If you had a Y connector for the battery and a volt meter, you could watch the voltage on the pack while you have the truck on to see if it's dipping down way too far when the servos move.

 

[granjer]

Trugggy, I'm having the same exact problems on my #4907. I'm using the traxxas charge adapter #3034, battery pack #3037 with standard trickle charger. I noticed some things during diagnosing the problem.
1. it only does it after the pack is fully charged
2. it does notdo it with the factory 4 AA pack
3. my LHS swapped out the pack for another new one, so that eliminates it being the pack.
4. truck does not have to be running

I'm going to post some voltages later after I go to the shop and get my DVOM. I got my truck on 04/13, so I find it hard to believe that the servo is worn out already. To be continued!:\

 

[truggy83]

Yea this is puzzling. The transmitter batteries are fully charged and good. I just swapped the traxxas flat pack that was in the jato into my nitro stampede. The problem doesn't happen in the nitro stampede with either of the traxxas flat packs. I put an ofna hump pack 5 cell that was in the stampede into the jato and the problem doesn't happen then either. It only seems to happen when I have either of the traxxas flat pack 5 cells in the jato. I don't know what to think. I noticed when the flat packs are fully charged that I have to pull and release the throttle trigger rapidly in order to get the servos to jerk and the problem to occur. Otherwise on a fully charged flat pack I can't even get through a full tank of nitro before the servos start acting up. It isn't just the throttle either. The steering servo has a bad lag to it and the wheels sometimes take a lot longer than they should to return to center when I let off the steering controls.

Trugggy, I'm having the same exact problems on my #4907. I'm using the traxxas charge adapter #3034, battery pack #3037 with standard trickle charger. I noticed some things during diagnosing the problem.
1. it only does it after the pack is fully charged
2. it does notdo it with the factory 4 AA pack
3. my LHS swapped out the pack for another new one, so that eliminates it being the pack.
4. truck does not have to be running

I'm going to post some voltages later after I go to the shop and get my DVOM. I got my truck on 04/13, so I find it hard to believe that the servo is worn out already. To be continued!:\

About the same time I got my truck too. Please keep me posted if you find a definite solution for this. I will do the same. As of right now I cramed my Ofna hump pack into the rear battery location of the jato and I have the traxxas flat pack zip tied to the rear shock tower on my stampede. Initial testing seems to show that this fixes the problem on the jato. I cannot get the servos to jerk at all with the ofna battery pack in it. If you have a different brand battery pack try putting that in and see if the problem goes away. I will not be satisfied running the hump pack crammed into the jato nor the flat pack zip tied onto the stampede. I want to be able to run the proper rechargable batteries in them. I will let you know if I find out any reasons why this is happening. I will call traxxas tomorrow.

 

[olds97_lss]

You could just cut your losses and get another OFNA flat pack.

 

[w bill]

It sounds like unbalanced cell in the battery pack it can cause that problem your having by the time you split them check them you would be ahead of the game just to use a different battery pack.

 

[olds97_lss]

Or you could try cycling the pack a few times using a discharger of some sort. This would hopefully even the traxxas packs out.

I just use a brake light from my 1:1 with both leads soldered so I get the "taillight" and "brake light" filaments burning. Not a lot of load, but enough for a receiver pack to drain in under an hour.

I normally cycle my packs once a year in the spring to prepare for the season.

 

[granjer]

I have tried 2 traxxas hump packs and 1 dynomite pack. All do it. I have heard dynomite packs are crap, heard they're good. That's stil up for debate. My question is, why didn't the new traxxas pack do it right out of the pkg, before charging? Gonne run some voltage tests this afternoon. Keep ya posted. That would make 3 bad packs in a row for me. Odds are against that.

 

[w bill]

Or you could try cycling the pack a few times using a discharger of some sort. This would hopefully even the traxxas packs out.

I just use a brake light from my 1:1 with both leads soldered so I get the "taillight" and "brake light" filaments burning. Not a lot of load, but enough for a receiver pack to drain in under an hour.

I normally cycle my packs once a year in the spring to prepare for the season.

I fly a lot and usally at the start of the season i start with fresh ni cad packs i figure $60vs$1000 for a plane batteries much cheaper.Nothing is worth losing for a few bucks. Try what olds suggested first a good idea.

 

[truggy83]

I have tried 2 traxxas hump packs and 1 dynomite pack. All do it. I have heard dynomite packs are crap, heard they're good. That's stil up for debate. My question is, why didn't the new traxxas pack do it right out of the pkg, before charging? Gonne run some voltage tests this afternoon. Keep ya posted. That would make 3 bad packs in a row for me. Odds are against that.

Yea this would be two bad packs in a row for me. And they work fine in my stampede.

 

[w bill]

Yea this would be two bad packs in a row for me. And they work fine in my stampede.

Its hard to say without being there all i can say start checking vlotages connectors or any other possibilities.Wish i could be of more help to you.

 

[mtaylortank]

granger did you say you used the pack before you charged it????? I thought you are supposed to give them a good first charge before any use???? could that be a problem????

 

[granjer]

Yeah, the owner at my lhs tried it right out of the pack to duplicate the problem. And the problem seemed to have went away. Here's what I'm thinkin', the pack he tried had a "partial charge", then I charged it with my trickle and the problem was back. Same thing with my other 2 packs. What I think is happening is with a full charge, we're getting some sort of rfi until the packs run down a bit? I'm not sure what mah the std 1.5 aa batteries. Possibly a connection there. :\

 

[Raiden101]

I had a truck doing that, but only when it was running. It ended up being a bad servo

 

[granjer]

Well, I swapped out the reciever and transmitter and tried it again. Still glitching and cutting out. My throttle/brake servo are the only ones doing it. I'd agree with ya on the bad servo if it didn't correct itself when I switch back to standard alkaline batteries. I did some voltage measuring and here as far as I got.

Dynamite pack peaked out at 6.7v
Traxxas pack peaked out at 6.9v
New Alkaline batts were at 6.08v

I was going to do a voltage drop test on my servo to see how mch it was using (std #2055), but I have no way to tie in and I'm not about to go probing wires. I'm stumped and so is my LHS. Guess I"m gonna switch back to my old std pack till we get this figured out.:\

 

[mtaylortank]

that is messed up the only thing I have been thinking was what about the connectors??? could they be not making a good enough connect or maybe not tight enough of a connection???? I dont know...... I will keep talking to people to see if I can come up with anymore ideas for you..

 

[Raiden101]

It wouldn't hurt if you had an extra servo laying around to test it

 

[truggy83]

my jato ran fine today with the ofna hump pack in it. Still acts strange with the traxxas flat packs in

 

[granjer]

I even plugged the batt. pack directly into the reciever to bypass all switches and connectors. No bueno, still does it. I'm thinking of robbing a servo from my sons truck to swap out like Raiden said. THats about the only thing I haven't tried. If that 2 week old servo is bad, I"m gonna be miffed. I'll keep you all posted. See, the diff between truggy and I is it's only my throttle/brake servo acting up. Think he has both acting up. I might switch my servo leads at the reciever and see if the problem follows.

 

[granjer]

It wouldn't hurt if you had an extra servo laying around to test it

Well, I switched the leads at the reciever and the problem seemed to have followed. So I put an old Futaba I had laying around in it and wah laa! truck ran fine. Has a bit of servo growl at first, but I blame that on the condition of the taba servo. going to pick up a Hitec tues when the LHS opens back up a see what it does. Keep your finger crossed.