Do Higher C lipos run cooler then lower C

[d.a.v.e]

I took my boat out for its first run today, fully stock. I had 2 x 20c 2c 5000's lipos in the boat.

I would guess my run lasted about 5 min. All the electronics were cool when I brought it in but both my battery's were puffed up and very warm. Swelling on both have gone down after about an hr. I was wondering if I bought higher c rated batteries if they will run cooler and not swell? Maybe its ok if they swell but having had a lipo go up in smoke on me once before I tend to worry when I see puffing.

[Darin Jordan]

Generally speaking, yes...

[Doby]

Did the LVC kick in?

[TheShaughnessy]

those batts should power a stock MG pretty easily, who makes them?

[d.a.v.e]

Yes the LVC kicked in & they are True RC battery's.

Is swelling bad or normal when they are discharging? I have not experienced this with my RC cars before? I seem to recall its only bad when charging?

[Doby]

Boats and cars are totally different animals when it comes to battery drain. Running LiPos to LVC is generally not a good idea. How old are the batteries? Have they been drained to LVC before?

[planezero]

PLEASE do not charge puffed cells...
Do some google-ing ...

[d.a.v.e]

One of them has been run to LVC before on my slash once. Both are 3yrs old & have been raced 1 night a week for about 4 months of the year.

When I checked them on the charger after this run they were at 3.78 per cell & I put 4200mah back into them. So not too bad.

The batteries are not puffed anymore but they did puff when running. I have done some googling and it seems the consensus is its ok to charge if they go back down after puffing. But not to charge a puffed batt.

This idea scares me.. Wondering if you guys experience this? Thinking I will pick up another 40c batt to match a new one I have and try running that tonight or tomorrow to see if they puff?

I had the esc set to the low setting the manual recommended.. Wonder how it would do in the high setting?

[Doby]

Don't mix and match old and new LiPos.......the old one won't survive long.

[dana]

20c isnt enough.

[d.a.v.e]

So whats the min C rating I should be looking for if 20 is not enough? 30c, 40c, or higher? I picked up another 40c Venom to match the once I bought for my last race in March.

I'm thinking of getting something from hobbyking (like others here) but not sure which back order list to get on :)

I'm not looking to make this a true race boat but will be running with 6-10 other folks so I need to balance run time and speed.

[jac4412]

The higher the c rating the better... 25c is probably the minimum, 30-40 is solid and 40-50c is awesome.

[d.a.v.e]

How many sets of batteries do you guys have? Trying to decide if three sets of packs will be enough or how many more I should consider buying?

Seems our local club runs about 6 laps = about 1 mile per race + any warm up time (about 2min I'm told). Thinking that would be 3 sets + any for practice, guessing 5 sets would be needed? Not sure how much time there is between races for charging? I forgot to ask but would assume 2 heat races and a main?

[TheShaughnessy]

How many sets of batteries do you guys have? Trying to decide if three sets of packs will be enough or how many more I should consider buying?

Seems our local club runs about 6 laps = about 1 mile per race + any warm up time (about 2min I'm told). Thinking that would be 3 sets + any for practice, guessing 5 sets would be needed? Not sure how much time there is between races for charging? I forgot to ask but would assume 2 heat races and a main?

that depends on how many classes are racing. You could have over an hour between your heats so charging wouldn't be too much of an issue.

You should probably have at least 2 sets of 4s that you can run. Should get you though 2 heats with enough time to have the packs from the 1st heat charged for the main.

[martin]

The thing i find going to higher c lipos is what i noticed initially because i was using the exact same set up simply using a higher c battery things did seem to be cooler. But i found because things were cooler i could start pushing things a bit further as you do for more speed & you end up back to square one higher temps but faster still. I went from 25c to 45c now using 60c not in a Spartan buy the way. Martin.

[ron1950]

hey martin i have a friend that uses 60c batteries and melted the deans plugs...everything else was cool......u useing the 5.5's or what?

[Brushless55]

The higher the c rating the better... 25c is probably the minimum, 30-40 is solid and 40-50c is awesome.

[martin]

hey martin i have a friend that uses 60c batteries and melted the deans plugs...everything else was cool......u useing the 5.5's or what?

Im using 60c in 15"micro monos at around 50mph, I use bullet plugs but only 3.5mm as every thing is pretty small. Martin.

[d.a.v.e]

Wow just went to the pond and tried out my 40c's and they were way faster then the 20c's but they came back pretty warm as well. They are hard packs so its hard to tell what the actual temp was/is.

Before I went out I ordered 2 more 2cell 5200 30c's from hobbyking. Will be interesting to see how they perform? Now I just need a new charger & power supply. My little 50w AC charger is going to take 4hrs to charge up 4 packs for the next two 5min runs!

[Brushless55]

Wow just went to the pond and tried out my 40c's and they were way faster then the 20c's but they came back pretty warm as well. They are hard packs so its hard to tell what the actual temp was/is.

Before I went out I ordered 2 more 2cell 5200 30c's from hobbyking. Will be interesting to see how they perform? Now I just need a new charger & power supply. My little 50w AC charger is going to take 4hrs to charge up 4 packs for the next two 5min runs!

One thing I have noticed is if I run my packs beyond the 80% mark they do start to get warm as when I only run them to 65-75%

[d.a.v.e]

I'll try a 4 min run later tonight or tomorrow and see how they do? I noticed my older 20c's were not nearly as warm when I brought them in early today but have not hooked them up to the charger yet to see where they are at? Also I only ran them at about 80% throttle. Not sure which helped but they were not puffy this time... Just warm.

Thought I would post this link I found for anyone else that might not know anything about this stuff: http://www.rchelicopterfun.com/rc-lipo-batteries.html Seems to be a pretty good explanation of lipo's.

[don e]

I believe the ESC in the MG comes program for NIMH and must be changed with the Proboat programer

[d.a.v.e]

Finally remembered to bring my GPS with me today. My boat is fully stock.

On my 3yr old 20c lipos I got a max speed of 29.8mph
On my new Venom 40c lipo's I got a max speed of 28.2

Other then a few speed runs I've been running the throttle at about 3/4 and the packs have been coming back much cooler lately. Will be interesting to see how my new Turnigy 4 cell 40c's do and the new 2cell 30 c's do with the same boat configuration tomorrow? Only difference being tomorrow all the batts should have EC5 connectors if I can get to it tonight?

[tiqueman]

Timing high or low? Also, its said its not good for the esc to run anything but full throttle. A lot of on off and half 3/4 throttle will usually help to heat things up, not cool them down. 2S packs in series, I would not go less than 40C. Even at that, Ive done some goofing around w/ mine and Ive heated up some 2S packs in it. If your looking for great speeds and handling and a good run time for 4min heat racing, Id recommend going 4S2P. I run two of the 4S Turningy, 30C 4000mah in LSO and now I use them for sport running too. It just runs better IMO. I run on the stock motor, upgraded esc and am in the low 40s. After a 4 min heat, my batts are usually under 100 degrees F. Hope this helps.

[lectriglide]

On my 3yr old 20c lipos I got a max speed of 29.8mph
On my new Venom 40c lipo's I got a max speed of 28.2

Think you might be running too wet. Even bone stock you should be running mid 30's. Might also explain why the previous packs were coming in hot. Keep in mind that racers actually preheat their packs to 110 or so to get the best performance out of the packs. Those 40c packs shouldn't be breaking a sweat with the stock stuff.

[tiqueman]

I agree w/ lectriglide. Thats why I asked High or low timing. On high, my stock set up if I remember correctly ran 32 or 33. Maybe a bit more.. I cant remember.

[d.a.v.e]

I've got it set on high, but will try setting to low today. I'll bring a temp gun with me today but when I run full throttle I'm consistenly puffing both sets of hard case packs. Is that normal? Seems to take 30+ min for them to go back down? All the electronics are running cool but it did look like I have started to melt a deans plug? Hopefully I can get those swapped out tonight?

[lectriglide]

Leave it on high, that's where it should be. I recall reading about someone having the same issues as you and it turned out they were not leaving enough space between the strut and drive dog. When underway the flex was constricting causing the strut and drive dog to rub. Make sure to leave about a cable width of space between the two. And no the batteries should not be puffing.

[tiqueman]

Great point. Check the gap. And yes, leave the timing high. I was just curious as to if the speed was down do to the "low" setting. I wouldnt think it would be starving for power so much as to melt the deans, especially if everything is stock. Id say your binding somewhere... somethings not right.

Can you post some pics of how your running it, set up wise?

[d.a.v.e]

Leave it on high, that's where it should be. I recall reading about someone having the same issues as you and it turned out they were not leaving enough space between the strut and drive dog. When underway the flex was constricting causing the strut and drive dog to rub. Make sure to leave about a cable width of space between the two. And no the batteries should not be puffing.

Not sure what a drive dog is?

I'll post some pictures later tonight.