Ruckus lipo questions

[Gothenburg85]

Hey all, been searching around, but couldn't find answers to some questions I have about upgrading from nimh to 2s lipo. My truck is a stock ECX03014 Ruckus brushless 2wd w/ AVC, with a Tenergy tb6 charger. https://www.horizonhobby.com/products/ECX03014 My goal is to have better and more consistent run time for bashing without having to replace drivetrain parts, hence 2s not 3s.

- Discharge rate: I am not sure on the C rating range that is acceptable for this Ruckus. I read at least 20C, but am thinking 30-40C. Is there a proper range to be within to not hurt the battery or esc?

- Durability: Is the 2s similar enough to the 7 cell nimh in amps/volts that I won't be torching drivetrain components all the time?

- Temperature: Are there any temperature concerns running 2s for this truck? I can get a laser thermometer, but don't want to waste the money if the motor (Tazer 3300kV) will always run cool enough on 2s.

- General lipo question: what's the charging/discharging protocol for lipo? Never found a great answer in searching! Charge up, run it down, then... protocol for running again within a week? Is it ok to leave discharged at the 3.2V LVC, then charge it up before running like I would with a nimh? Or do you charge again right after running because maybe they hold a charge longer than nimh? Top off again before running if it's been a week or so, or is that necessary? It seems like you charge it to about 50% for longer term storage, over a week, is that right?

Can post in the Electronics forum if necessary. Thanks for any help, been having a total blast with this truck!

 

[Tamyosho]

I have the exact same car.

* I got 35C lipos as I also use them in my Arrma Typhon. The price difference was next to nothing compared to 30C which is all the shop had. The "new" Ruckus one comes with 20C, so it's probably OK though. More is not better but won't damage your car/esc.

* Sidenote: you can't run 3S with this ESC, it doesn't support it. The older ESCs did, the ones coming with the non brushless Ruckus might too, but not this one. Probably so you don't instantly shred the driveline.

* I've destroyed a few driveshafts. Currently running top of the line hot racing ones (other ones from HR failed me). Some people have modded their cars for Traxxas, other run MIPs or even brandless ones from ebay.

* I put a heatsink on the motor, just in case (cut out a standard heatsink to fit the cover). Never had issues. It only really gets hot if you run it in high grass, which is a bad idea.

*2S is a bit faster than 7cell nimh usually. 4-5 mph more maybe on a Ruckus? It's more constant too (just keeps going then dies instead of gradually slowing down).

* Storage mode on my charger is recommended for 3+ weeks. I prefer to have a battery fully charged and ready than leave it empty, they get damaged if they go low and hey, you never know when it stops raining long enough to go out.

 

[streetracer621]

I have a Ruckus that came brushed with the 2S Lipo, but I have upgraded to a 3930kv brushless system that I run on 2S 35C 3300 mAh packs. I did run a 5200kv for a little while, but stripped the stock spur gear with it. I bash my Ruckus hard with the 3930kv and 2S, and have not broken anything. I am running a 20 tooth pinion and 90 tooth spur 48 pitch gears.

 

[Gothenburg85]

I appreciate the replies, gents.

It sounds like ~30C is a good rate for me. I really don't need any more top speed for what I like doing, and want to replace as little in the tranny/driveline as I can. I could always back off the punch as well I guess if that doesn't smoke the clutch. Ideally I'd just like the power I get from the nimh batteries I have, but in linear delivery and for a longer amount of time. Faster charging with lipos is a side bonus.

Temperature does not seem to be an issue, so that's good. I might just get the temp gun to be safe though, and monitor the motor/battery. From my searching, brushless motors shouldn't get much over 170F, batteries 110F.

As far as charging, I'll charge up once run down. Storage mode if not used for a couple weeks or more. I guess my only question here is the "standby" discharge rate of lipos? Do you top them off if sitting for a few days to be safe, or is that unnecessary or hurt the battery at all?

 

[streetracer621]

I top off/balance my lipos if they sit for over a day, but I also have all of my stuff stored in a chilly basement. Hasn't seemed to noticeably affect my packs.

 

[Gothenburg85]

* I've destroyed a few driveshafts. Currently running top of the line hot racing ones (other ones from HR failed me). Some people have modded their cars for Traxxas, other run MIPs or even brandless ones from ebay.

Which driveshafts are you running out of curiosity, the SECT288RC? Seems like people have hit-or-miss results with replacement driveshafts.

 

[Moldorak]

Which driveshafts are you running out of curiosity, the SECT288RC? Seems like people have hit-or-miss results with replacement driveshafts.

Yup. (Tamiyosho here squatting a friend's computer).