Batteries are getting hot and puffing

[ethomp]

Just got an Aqua Craft UL-1, using all stock components [60 amp esc and 36-56 2030kv motor] Run times are only 5 to 6 mins. with gens ace 5000mah
40c 2s. Motor and esc are comming off pretty cool but batteries feel to warm to me and now after a few runs their puffing. Never had this problem with my rc cars and trucks. This battery in the pics just puffed at the very end. Not sure what to change to stop this. Thanks
Eric

[photohoward1]

OK what Prop? Your RC cars never Drew 60 amps. When you recharge the Batts how much are you putting back into them? 6 minutes of run time is way to long.
The rule of thumb is 80%. never go below 20% left in the tank. 5000mah cells that means 4000mah used or 1000mah left in the cells. If you are taking them to zero then they are already ruined..

[Make-a-Wake]

Yeah............"only" 5-6 minutes of runtime is very long for 5000 mah...................do you have an LVC on the ESC? What voltage are the cells after a run? 3.7v per cell is depleted in my book.

[ethomp]

The prop is stock L40x57 and the batteries come off at 3.5 to 3.6v the esc is supposed to have a built in lipo cut off. so how long should a 5000mah battery run for on this type of boat?

[Make-a-Wake]

Coming in at 3.5-3.6v is every bit of 100% depletion to me........................there is no standard for runtime, its all based on the entire setup, but I think it should go 4 to 4 and a half minutes myself.

[ethomp]

Thanks for the info, I had no idea how long to run this, just ran it untill it started to slow down or untill it stopped.

[Make-a-Wake]

Thanks for the info, I had no idea how long to run this, just ran it untill it started to slow down or untill it stopped.

Thats not good news..................let 'em sit overnight and recharge them under supervision. I bet they take more than 5000mah. I have had a couple lipos swell just a bit and continued using them conservatively and they have worked well.

[785boats]

The ESC does have a cut off but it is set at 12V or 3.0V/cell. With the higher 40C rating packs the voltage curve stays up above the cutout setting longer under load & the battery fully discharges its capacity before the cutouts are actuated. By the time you get the boat untaped & measure the voltage it has recovered to 3.6V. The old 20C & 25C packs would drop down in voltage while there was still some capacity left in the tank.
You are going to have to cut your run time as Make-a Wake suggests.

[Brushless55]

Yeah............"only" 5-6 minutes of runtime is very long for 5000 mah...................do you have an LVC on the ESC? What voltage are the cells after a run? 3.7v per cell is depleted in my book.


The prop is stock L40x57 and the batteries come off at 3.5 to 3.6v the esc is supposed to have a built in lipo cut off. so how long should a 5000mah battery run for on this type of boat?

the fault of the stock esc is the lipo cut off
it has a stutter bump at 12v and cut off at 11.6v, that's 2.9v per cell!
and having better packs like these lets the cell go lower than other packs would

[Make-a-Wake]

having better packs like these lets the cell go lower than other packs would

You're exactly right.........................if he had cheapy 20c's they would have cutoff much sooner.

[Brushless55]

You're exactly right.........................if he had cheapy 20c's they would have cutoff much sooner.

I had some 20c in my UL-1 on it's first few runs, and it would cut out and still leave my cells at 3.75+ per cell..
but after learning from OSE and other forums about the 20% rule.. I time all my runs, Lipo cut off or not.. :rockon2:

this is the very reason I tell others not to run their rc down to LVC, land, air, or sea.. :smile:

[siberianhusky]

I run the same combo with a number of different brands of battery in a few different boats, set my timer for 3.5 minutes then finish the lap and bring the boat in, about 4 minutes runtime. High 60 to low 70 amp draws, last week I saw spikes of 109 amps on take off in my SAW cat! Didn't think the esc would take that!

[Brushless55]

I run the same combo with a number of different brands of battery in a few different boats, set my timer for 3.5 minutes then finish the lap and bring the boat in, about 4 minutes runtime. High 60 to low 70 amp draws, last week I saw spikes of 109 amps on take off in my SAW cat! Didn't think the esc would take that!

I'm running a constant 80a through my P-Spec DF33 UL-1 powered machine..
that motor is a monster! :rockon2:

[ethomp]

Well guy's, I've learned alot in the last 24 hrs. thanks to all your responses. I also found the Aqua Craft UL-1 section right here on OSE and I found several threads that talked about this very subject. Comming from 1/0 touring car and some 1/8 off road, the batteries last much much much longer and there is nothing in the owners manual that covers the use of these newer high power batteries. I have one battery I use for race only, Revtech 6000mah 60c. I'm sure if I had 2 of these I would have used them and would have destroyed them and at well over $100 apiece NOT GOOD!!! So I'll be looking for some low cost soft packs. Thanks again,
Eric

[mtbenjamin77]

Well guy's, I've learned alot in the last 24 hrs. thanks to all your responses. I also found the Aqua Craft UL-1 section right here on OSE and I found several threads that talked about this very subject. Comming from 1/0 touring car and some 1/8 off road, the batteries last much much much longer and there is nothing in the owners manual that covers the use of these newer high power batteries. I have one battery I use for race only, Revtech 6000mah 60c. I'm sure if I had 2 of these I would have used them and would have destroyed them and at well over $100 apiece NOT GOOD!!! So I'll be looking for some low cost soft packs. Thanks again,
Eric

get some sky lipo 30c from hobbypartz about $40.00. I've been running my SV27 on 5s2p with the aqua 60amp esc. I run it down till it cuts off almost everytime. I'm putting 2800mah back in a 2650 mah pack. And still no puffing and they balance just fine. the best part of it is if i do ruin them they're only $40 not $100+.

[Brushless55]

get some sky lipo 30c from hobbypartz about $40.00. I've been running my SV27 on 5s2p with the aqua 60amp esc. I run it down till it cuts off almost everytime. I'm putting 2800mah back in a 2650 mah pack. And still no puffing and they balance just fine. the best part of it is if i do ruin them they're only $40 not $100+.

I'm betting those packs are actually 3300's not the advertised 2650mah :rockon2:

[mtbenjamin77]

I'm betting those packs are actually 3300's not the advertised 2650mah :rockon2:

I use two of these and they're only $30.00

http://www.hobbypartz.com/77p-sl2650-5s1p-30c-5555.html

[Brushless55]

I use two of these and they're only $30.00

http://www.hobbypartz.com/77p-sl2650-5s1p-30c-5555.html

If I didn't have so many packs right now, I would try some of those out..
thanks for posting..

[ethomp]

Just got back from another run with a pair of zippy soft packs 5000mah 45c 2s, move the strut down 1 1/8 in from 3/4 in. and man was she flying. Set my timer at 3.5 min for a total run of 4 min. and the batteries showed 3.70v each and took 2211mah to re charge them, so I think 4 min. is going to be the max time for this set up.

[Brushless55]

Just got back from another run with a pair of zippy soft packs 5000mah 45c 2s, move the strut down 1 1/8 in from 3/4 in. and man was she flying. Set my timer at 3.5 min for a total run of 4 min. and the batteries showed 3.70v each and took 2211mah to re charge them, so I think 4 min. is going to be the max time for this set up.

Glad to hear you got a good run!
Where is the bottom of your strut to the bottom of the sponsons?
Thanks

[785boats]

You do have a couple of other options.
A lipo Shield is set at 3.2V cut off & that usually leaves some capacity in the pack at cut out. You would have to do some testing. But it would be cheaper than new packs & you could use your good race packs.
http://www.offshoreelectrics.com/proddetail.php?prod=de-liposhld-32&cat=136
Or Replace the ESC with one that has programable cutouts that can be set to 3.2 or 3.4V You would only need a $50.00 Turnigy 120A for that set up.

[ethomp]

Not sure how to get that mesurement I took it from bottom of hull to bottom of the strut where the prop shaft goes through. I ended up moving the strut back up 1/8 in. might be alittle slower but I seem to have more control in the turns. THIS THING IS TO FAST FOR OUR LITTLE POND!!! Need to find bigger waters.

[Stinger9D9]

It's also worth mentioning that the 40x57 prop is not stock on the UL-1. It's actually a pretty agressive upgrade that pushes things that much harder. You may want to try a 40x52/3. The lower pitch will slow things down a bit and lower the current draw.

I've been messing around with mine on that prop (and I have a pretty good "internal timer" that reminds me when it's time to bring her in), and everything stays nice and cool.
FWIW, I've never ran a set of batteries down to the stutter bump on an AQ ESC. I always suspected they go way too low for my comfort level.

[Make-a-Wake]

Just got back from another run with a pair of zippy soft packs 5000mah 45c 2s, move the strut down 1 1/8 in from 3/4 in. and man was she flying. Set my timer at 3.5 min for a total run of 4 min. and the batteries showed 3.70v each and took 2211mah to re charge them, so I think 4 min. is going to be the max time for this set up.

Something doesnt add up here.....................you took them down to 3.7v per cell and they only took 2200mah.........????......less than half of the capacity.........???....either you had a typo or the charger quit way before they were done or they are not 5000's. My 5000's take 5000 or better when at 3.7 resting voltage.

[ethomp]

Yes your right, that 3.7v reading was taken from another pack just forgot to go back and change my typo. I've been testing a brass 40-52 and it runs real good on that prop I just lose top end speed but after 4 min everything comes off nice and cool. I also ran a brass L40-57 and I think its out of balance because the back end starts to wag like a dogs tail. The best prop so far have been the stock plastic ones [sv27] I though I read somewhere that they were a 40-57? I need more batteries, these 4 min runs suck!!

[Make-a-Wake]

Try an x442.............a 2 blade will rev our better.

[ethomp]

I'll try that, thanks