Only 8 minutes with Brushed Trinity C027

[soniccj5]

Today I decided to give my VONATS car a run before Sunday.

Brought it to work and ran it on an empty floor in our building. I have a Brushless Havoc speed controller with a Trinity C027 brushed motor(can't run my 10.5 at the VONATS) with a trinity 3300NiMH battery and it only lasted 8 minutes.

Gearing:

23/83 RPM 2:65 transmission FDR 9.56

Tires:

B4 HoleShot

Could my 1 year old battery be bad already? I only brought one of my batteries to work so I can not test the other one.

Thanks,

ED

[slotcarrod]

Has the battery been sitting a while? If so cycle it a few times!

8 min on a 3300 at race pace is about right, although, your gearing seems low for a stock motor on pavement. Try a 25 or 26 pinion, although this will make your run times even less. For a tight indoor off road track, you can go back to the 23 or 24 pinion.

How long are the Vet Nats races, 5 min? If so you should be ok in any case!

[soniccj5]

i only used the battery twice since the last years VONATS.

ED

[soniccj5]

I just thought of something else. I was mostly holding it wide open. Maybe when I get on a tight track it will last longer.



Thanks,

ED

[Jay Dub]

If you haven't used your NiMh's in a year, they could likelly be hurt. This is the reason (most anyways) of why I switched away to lipo's. NiMh's generally need to be charged on a regular basis (1000 mah for every week they sit without use), and cycled as well. In your case, they need to be peaked every 3 weeks to avoid damage . The catch is that every cycle you put on them can drastically reduce their life. You must also be very carefull not to over discharge the packs as well. .9v per cell is a good rule of thumb, but this varies per cell type. Best thing you can do is put a few cycles on them. Let them rest for a few days between cycles (for best performance), and use a good tray (the Rayspeed tray is nice) to equalize the cells after running. Also never run the battery down in the car. As soon as it starts to dump, pull it off, and tray the batteries to avoid over discharging individual cells (which will KILL them). If you follow these directions. you can expect to get around 25 quality cycles out of a good matched pack ! . Did I mention I like LiPo's? -Jeff

[slotcarrod]

Cycle your packs a few times, if they don't wake up, buy a lipo and a lipo charger! And then never look back!

[Greebo]

Cycle your packs a few times, if they don't wake up, buy a lipo and a lipo charger! And then never look back!

That was my plan when I got my car/batteries out after about 8 years sitting in a box... my 2x 3000 mAh NiMH's were giving me about 800 mAh.
After about 6 cycles on a cycling charger (I bought a Duratrax ICE), I'm getting about 2300 mAh out of them again.
The LiPo's will have to wait a little longer (for the RC10 anyway - the RC8 is using LiPos and I love 'em)

[menace]

Brushed motors and round cells are not very efficient compared to brushless and lipo. Cycle your batteries a few times and clean your motor, but don't expect to get more than about 10 minutes of runtime, especially if you are running wide open throttle.

[floodx]

when i first started back i bought a 3300 mah nimh radioshack special to test my esc - thought is was awesome compared to the nicads i use to run back in the day. fast forward until about a week ago i got a 2s 3200 mah lipo for $5 more than the shack special and I am amazed that it doubled the performance. I am surprised I didn't break the car in half with the wheelies and power that the lipo added.

I will have to say I was skeptical but the lipos are worth the extra you pay for em the performance increase is incredible.

dump your nimh and buy a lipo

[Greebo]

A while ago I purchased an eLogger V3 from eagletree to log data in my RC8. Last week I hooked it up in my RC10 with my NiMH battery... Now I understand why people say LiPo is so much better.

First though an explanation of LiPo "C" rating as I keep seeing statements which indicate its very poorly understood
The "C" rating of a pack is the maximum discharge current rating of that pack at which the pack sustains 3.7V per cell.
The second thing often misunderstood is that two 30C packs only have the same current capacity if they have the same Ah capacity. 1C is always equal to the Ah rating of your pack. For my 30C pack, it's a 5Ah pack, so 1C = 5A. 30C is therefore 150A. If I had a 4Ah pack, it would need to be 40C to have the same current capacity (160A).

Now on to my few month old 4.2Ah 6 cell NiMH battery.... The datalogger shows peak current draw of about 40A whenever the buggy takes off from a standstill and at the same time the pack voltage goes from about 7.6V down to 6.2V... yep, it drops 1.4V when I'm drawing significant current from it. If that was a LiPo within its C rating (such as a 4Ah/25C pack), instead of 6.2V, I'd still be getting 7.4V or higher supplied to the ESC/motor. Obviously the voltage drop is not as high when taking off out of a corner etc (generally between 25A and 30A and only down to 6.8V), but its still significantly worse than a LiPo would be.

Sure opened my eyes - my new LiPo's should be here tomorrow!

[67falcon]

HEllo All,

I got my RC10t Stadium Truck running again. I am using a 12x2 Turn motor, Novak Rooster reversible, and a 7 cell 4500nimh Battery. What a wake up compared to the original battery I had when i purchased this truck back in 1995. The only issue I am having is the Spped controller shuts down after about 5 minutes do to heat. Novak says it will shut itself off before it gets to hot (which is good- no damage). I orderd a fan for it should be here next week.

Now my big question is if I go to LIPO will I still have the heat issue? I purchased a charger that can handle charging all the batteries out there. Currently my motor and battery dont get very hot, warm to the touch but not hot. The speed controller you cant touch with out leaving a mark lol.

I want to keep the truck stockish so that is why I havent gone brushless yet. If I decide to do a brushless car I think I am goin to start from scratch and build from ground up.

Thank you for any inputs.

[peetbee]

Novak's website says:
"Operates down to a 12-turn brushed motor (at 6 cells Ni-MH)"
So I'm not surprised it's overheating!! You're on the limit motorwise and above the limit for that motor with your cells

Whilst the fan may help, I would post up the gearing you are running and ask for advice as that could be making it run hot if it's wrong (I have no idea for trucks tho, so we'll need someone else for that advice!)

I think you may be asking a bit much of it tho!

[67falcon]

Thank you for the input. I am running the stock stealth tranny. I did take it apart last night and clean the gears, plus lubed and adjusted the diff. When you ask for gear ratio are you asking about the gear on the motor end and Clutch side? I was also thinking about doing the RPM 2.65 upper shaft conversion. But I also been looking at putting in a T4 top shaft and clutch. It doesnt run as hot with the 3300MaH 6cell, but it does run very hot with the 4500MaH 7-cell.

Thank you again for your help

[soniccj5]

I decided to pull the trigger and order a cheap LiPo setup. Should have it by next week

Venom 7.4 5000mAh 40C

I heard mixed reviews regarding the Venom products, but for what I do, I did not need a full blown race battery.

Should have an update in a couple weeks after I get it mounted.

Thanks to everyone who replied.