VS1 with UL-1 FE...Looking to see what run times people are getting.

[Mike Luszcz]

I am running the VS1 with UL-1 motor, Turnigy 120a Marine ESC, and Flightmax 5000mah 4s1p pack, X640 prop, and I am getting between 7-8 minutes run time staying mostly wide open, just slowing to turn around, as its a narrow pond at one end. Does this sound about right? My motor, and esc stay very cool, my packs are warm, but not burning to the touch, and they swell just ever so slightly right after running, and return to there totally flat outer shape 30 minutes after running. My question is...Is this normal? Also, every time I run, I run to the 3.0v cut on my ESC, and when I recharge, the packs are refilling with 5350mah. How can a pack that is rated at 5000mah charge more in than what its even rated? I charge at 5.0a using a Thunder Power 610c charger. I am mainly concerned with the batteries cycle life in all these questions. Should I make my cut off earlier? Even when I cut them at 3.4v, they put back probably 4700mah, so I'm not sure. Is it possible since Zippys are cheap batteries, probably tossed quickly down an assembly line, they maybe ran out of the 5000mah, and had some 6000mah cells and put those in because thats all they had at the time??? I dunno, im just looking for some peoples experiences with charging lipos, and what have they seen, and what is normal. Lastly, with that 610c charger..Does it balance automatically during charging, or is there a balancing feature. My batteries always seem to balance back, but I may have a cell off by .02volts, and I am not sure if thats normal (ex. 4.176, 4.185, 4.182, 4.180 might be a normal reading after charging). Thanks and I hope this is not to confusing. Mike

 

[AlanN]

I would say you are running too long. We generally use an 80% rule as far as how much the cells will give and take. 80% of 5000mah is 4000mah. I do not exceed that or take my cells down to 3.0V/cell. It would not be surprising if you start to see the cells building up resistance and your run times and speed will decrease. My guess is that you have already damaged them since they are getting a little puffy after each run. Please do a search on proper lipo care and see what others have to say but they will mostly back me up.

When you charge heat will use up mah's and I'm guessing that you are charging the cells when they are warm.

As far as balancing goes your #'s are not too out of whack but if they are .02 difference you most likely have a cell going bad.

Also, I run the same motor/hull with a similar prop load and only run mine for 2-3 minutes since this is a race setup.

 

[Mike Luszcz]

Dang, .02v out of balance is that bad??? Man, what have I done. Seems like the lipos run time is so short its almost worthless! Imagine a 3500mah pack, you would not get a minute out of it. Well, I guess the good news is I am learning my lesson on low cost cells, and not $250 enerlands. I was only discharging to 3.4v a cell, but my friend that is into 1/8 scale thought my run times were way short and that 3.0v would help, but I don't think he knows about the mah discharge as much as others do. Well, I will change my lvc to the highest possible tonight and see what happens. Thanks, Mike

 

[J Solinger]

Like Alan said use the 80% rule. The low voltage cut off is just an extra safety measure and shouldn't be used as an indication of when to bring the boat in. It does sound to me like your set up is just right. Going down a size or two on your prop will give a little better run time.