1515 2200kv heat issues in buggy - RC-Monster Forums

KniteWulfe · 10.10.2010, 02:46 AM

Ok, couldn't get the chart from yesterday, but... I logged some mopre runs today, 1st with a 14T and 2nd with a 16T pinion. I put a huge heatsink and fan on to save my motor and set the LVC to 3.4.

Now after looking at these charts it seems that the battery is complete junk! I think I got about 10 runs out of this pack. All of my turnigy packs are having the same symptoms, losing power and cogging, and hitting LVC after a short time. Is this what has been causing my heat issues all along?

sikeston34m · 07:17 AM

Quote:

Originally Posted by KniteWulfe

Ok, couldn't get the chart from yesterday, but... I logged some mopre runs today, 1st with a 14T and 2nd with a 16T pinion. I put a huge heatsink and fan on to save my motor and set the LVC to 3.4.

Now after looking at these charts it seems that the battery is complete junk! I think I got about 10 runs out of this pack. All of my turnigy packs are having the same symptoms, losing power and cogging, and hitting LVC after a short time. Is this what has been causing my heat issues all along?

IMO, the charts don't look horrible in terms of the packs performance, but...........

When is it cogging? on startup? It cogs more in the 16 tooth, than the 14 tooth, doesn't it?

What top speed are you geared for?

Cogging itself creates HUGE amounts of heat VERY quickly. Cogging also will suck the juice out of the pack very quickly.

What are your ESC settings?

I would look at addressing the cogging issue itself, then log some more runs. You have to get the cogging stopped.

The cogging isn't necessarily the Lipo.

Cogging is usually the result of improper gearing or improper ESC settings.

KniteWulfe · 03:32 AM

Start power low, 0 timing, no punch. Never cogs until about halfway through the pack, on startup, and gets much worse as the pack gets low. Did you see the voltage dips on the 2200 16t graph? I hit the 3.4v Lvc after just 1400 mah. Gearing is for about 39 on the 14t pinion or 45 on the 16.

Also keep in mind I had a huge heatsink and fan otherwise my temps will hit over 200 even on the 14t. The temp spike happens right around halfway through the pack when the power suddenly drops and cogging starts. It's the same for both of my turnigy 4500 30c packs and the pairs 5200 30c packs. In fact it is worse with the 5200s. It didn't cog at all when the packs were new, and didn't have the power loss or other symptoms but the heat. It didn't even cog with the 17t at first.

I rebuilt the diffs and changed the bearings, and checked and triple checked the drivetrain for any signs of binding.

Anyway I've got over $400 worth of thunderpower packs on the way. If they don't help the issue at least I'll save a bunch of weight and eliminate that possibility.

pinkpanda3310 · 10.10.2010, 08:40 AM

Quote:

Originally Posted by KniteWulfe

It's the same for both of my turnigy 4500 30c packs and the pairs 5200 30c packs. In fact it is worse with the 5200s.

I notice on those graphs that the issue arises when the temp gets to 125-130. Your larger mah packs probably help to heat the motor just that little bit quicker.

I would imagine the esc would be getting fluctuations of temp at the same point but harder to notice if you are just using a gun and that's roughly when the fan kicks in.

Given it happens to any motor but the issue arises when the motor gets to a certain temp, one might assume mount is not integral at those temps. However, the car still rolls freely with no binding. Does it roll freely in reverse? I ask because that would be the direction of pressure on the drivetrain under acceleration.