Ouch! battery got so hot it melted the shrink wrap!!!

[Thirdgen89GTA]

My temp gun reported 213* in some spots with an average reading of about 195*!!!!

Damned hot, way too hot. The motor is only reporting 138* which is about right.

This is a Novak 4.5R brushless system in a Tamiya F201 F1 car. The batteries are Epic dreadnaught 3,000mah packs i had from previous cars using Deans Ultra plugs. After the run the leads and connectors are only mildly warm to the touch, the real heat is found in the cells themselves.

Why are the cells heating up so much? I don't remember them heating up this much when I was running them in my Losi XXX-T w a 5.5R system.

Advice is much appreciated right now.

BTW, its pretty quick, but not quite the top speed or acceloration i was expecting. Gearings too tall which is probably leading into the packs running so hot, but my adjustable motor mount hasn't arrived yet so I can't throw a different pinion on the motor.

[UE-Maxx]

Are the batteries old?

[Thirdgen89GTA]

pretty much new, only 2 months. I only had 1 eletric car running and I have 5 packs that I use so they were lucky to see about 8 runs a month.

I think the gearing might be too tall, but the motor isn't overheating all that much. Can't do anything about the gearing till the adjustable motor mount arrives. I probably won't run it again till I can play with the gearing that battery got really hot for my tastes. 200* is HOT!!

[UE-Maxx]

Hopefully it is the gearing.

[BJoe]

Probably a combination of gearing, a more enclosed than normal body, then if you were running on one of the hotter days recently, that too.

[Thirdgen89GTA]

I only got it running last night. Made 2 runs with it over 3 hours, letting the pack cool after each run, and after each charge. Each run lasted about 10 minutes with mid to high throttle.

[Thirdgen89GTA]

what would a average temp for a nimh pack be after a hard race?

novak says the motor should run about 160*, and the BL esc should be about 160 to 180*.

But what about the batteries?

[Nexus]

If you were running down to the last milliamp in your pack they will for sure get hot. Even in a 5 minute race with a stock 27T motor the batteries get hot. So running for a full 10 minutes with a 4.5 it's not surprising your packs came off pretty hot.

If you gearing is fine and the motor isn't overheating I probably wouldn't worry about it to much. Unless you think they are overheating and expanding which means they might vent.

Otherwise it's normal for packs to come off pretty hot.

[Thirdgen89GTA]

Hot enough to make the shrink wrap shrink and split cause it pulled so tight?

I still don't think I'm going to get the power and speed I want out of this thing till I go LiPo but I'm waiting for Li-ion, or LiMag to become more popular. Don't really feel like dealing with the whole "charge in fire proof box thing".

Still, perhaps its the batteries that are limiting the power. They weren't exactly the best batteries I can get. $42 for the pair shipped from Tower.

[kevinF]

is there maybe some binding causing stress on the motor and overheating the pack??? just thinking of ideas

[Ponch]

It might just be the quality of the pack; the battery bars, the cell types (brand), their ability to dump a bunch of power at once, the thickness of the wires, the connecters if they're not deans. Could be alot of stuff though.

[Nexus]

If you are running this 4.5 in an offroad car the motors and batteries really shouldn't be stressed much. Offroad is way less taxing on motors and batteries then 4WD onroad.

Something might just be weird with the pack and the connections. I would look into some nice "matched packs" if you want pretty good runtime and definitely more power then those stick packs give you.

I hate to "plug" sponsors but Hurricane Motorsports can make/sell you matched stick packs that would be awesome.

[Thirdgen89GTA]

Its a Tamiya 1/10th scale F1 car. The F201 chassis. Car is only about 3lbs with a battery in it.

Sadly because of the design of the car the battery packs MUST be of a 6cell stick design. No other type of pack will fit in the space provided. The connections are barly warm to the touch, I'm using Deans ultra connetors and the soldering points are cool to the touch as well. I'm not picking up any unusual resistance from the connections.

When I had a 5.5R in my XXX-T I had originally used the tamiya plugs there were on the original connectors. On the first hard run, the plastic fused together and I had to cut the wires from each end. I put deans ultra plugs on it then and never had a problem there after.

[Tex]

I say get some quality packs as the next thing you do, $42 for a pair shipped means they are pretty cheap batts. When I ran electric my batts were $60+ each and well worth it.

[Thirdgen89GTA]

did't want to spend alot of money batts right now as I want to get
liPo for the car, or LiMag when it becomes more available.

[Tex]

oh, that's right.... I did see that above

[Thirdgen89GTA]

I think the batteries fried themselves though.

Total power and run time are down alot from what they were before. On a fresh charge its simply a dog now. I think that one blast to 200*+ damaged the cells and now they won't take a full charge.

Oh well, there is always my Nitro cars.:joy:

Maybe I'll sell it off and drop the 4.5R system into my batmobile.


21" of 1/10th scale goodness.:racing: