p01rogue

I've been running my sv27 on 14 cells with no problems for a year.

Thinking about ordering 2x 2S 5000mah lipos.

But was wondering if the stock esc would possibly handle even more power like running a 5S setup?

jcplinux42008

I belive the max voltage is 16.8 or 14 cells , you could always go over it but the risk of heat damage or fire goes up , aquacraft hasn't put alot of info out about the esc and the specifics except it can run 14 cells and its a 45 amp speed control. I don't know what that voltage is , but as long as its not over the max it can handle 14 cells , or 16.8 volts , you should be fine. The mah rating doesnt matter that much mostly effects your runtime. So too answer your question , follow the guidelines becuase its been my experience that if you try too push it you will break it , then again if you have the money too buy a new speed control if you break go for it.

detox

The voltage of two 2s packs equals a safe 14.8 volts for the Super Vee esc. The 18+ volts of the 14 nimh cells will burn up your esc before the two 2s packs will. Super Vee lvc is only 5.4 volts so bring your boat in early to prevent cell damage.

Using the lighter weight lipo's will cause your boat to be very fast and more loose handling.

BTW the max recommended voltage is 18 volts for the stock esc.



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WakeBoardnBash

18 volt with a limit of 4s, 5s the esc WILL burn up

jcplinux42008

so 15 nihm cells is the max , thats an odd number , what does the 4s or 5s mean , i don't use lipo batteries? I understand the need for the lvc for lipos but it gets annoying with nihm cells , any idea why it cuts off when my boat is still planing and seems to be going a decent speed , nothing is getting hot either?


Check your math 14 cells is 16.8 1.2 volts per cellx 14 = 16.8 , the motor is rated at 18v not the esc. not trying to be rude just stating a fact.

Silent-AV8R

Good link to understand the S and P thing

http://scriptasylum.com/rc_speed/_lipo.html

detox

Most all NIMH cells are advertised @1.2 volts, but actually a good single fully charged NIMH cell will read 1.3+ volts on the volt meter. A good fully charged LIPO cell will measure over 3.7 volts per cell (5s means five cells in series).

Do the math:

NIMH: 1.3 volts per cell x 14 NIMH cells = 18.2 volts

LIPO: 3.7 advertised volts per cell x 5s lipo = 18.5 volts

5s lipo may work with the stock Super Vee esc, but I would check total pack voltages before doing so. I bet the total 5s LIPO pack voltage will be very close to 19 volt when added together! [8D]

Buy a voltmeter.

flip3d454

My Feedback: (35)

s is for series and p is for parallel.
so its 2s1p is how it is sold.
so that is a 2 cell batt.
a 2s2p is a 2 cell in series and another 2 cell thats in parallel.

get it.

jcplinux42008

Actually there is also a voltage drop while under a load , sure a fully charged cell is 1.3 for a little bit , but it won't stay that for the duration , or even halfway through it , as advertised is what i go by , a do have a volt meter in fact i have multimeter , if you watch it right after a charge the pack slowly drops down too its normal voltage. If they say its good for 14 cells its good for 14 cells , in fact the ib4200 say at a 35 amp discharge rate they drop too 1.195 volts , voltage starts going down immediately after you start going in the water. Im sure the voltage drop isn't that much in a lipo but in a nihm i don't think you can consider 14 cells as being 18.2.
Oh and also flip3d , i looked up stuff about lipos right after this out of curiosity and yes i do indeed get it , i also want some lipos now , i just don't want to deal with the special care they need.

ryan_t888

If the stock ESC is rated for a MAX of 14 cells NiMh, it most likely has a Max voltage of somewhere around 18v. If any more than 18v is applied, the caps will just burn up immediately after the cells are connected. Load voltage is irrelevant for an ESC.
You can't over volt an ESC, they will burn up.

A 5s LiPo pack will be at 21v when fully charged!

The only thing governing a motors limit is current and max RPM until it flies apart. All other information is derived.

Ryan

SV27dayton

My experience is the motor will get hot (too hot) in most cases before the ESC.

detox

I just checked voltage of my charged cells.

14 SUB C NIMH cells = 19.03 volts (charged two days ago)

5s LIPO = 21.31 volts (freshly charged)

4s LIPO = 17.1 volts (freshly charged)

ryan_t888

What charger are you using?

Your 5s pack is around 4.262v per cell and your 4s pack is around 4.275 v per cell. This is considered dangerous. Your charger should stop at 4.200v per cell. At the most ~4.230v per cell. Not only is your charger over charging it has a great inconsistancy!

Ryan

p01rogue

I think i'll just buy 2S.

I'll run 14 cells back to back against the 5000 lpos and get a radar gun report for all to compare.

detox

I am using the small $26.00 Venom balance charger to charge my Venom batteries. It has a .75 charge rate which charges thru the balancing tap. I have noticed my packs are swelling a little. What causes pack swelling?

I have two Hyperion 606 AC/DC chargers on order. Thanks

Raydee

My Feedback: (3)

If Venom lipo's are anything like the Venom NiMH cells then I would guess that the swelling is coming from the very poor quality of cells that Venom uses. My personal experience with Venom batteries hasn't been positive at all.

p01rogue

Pack swelling caused by overheating during discharge or overcharging situation.

I would not trust that charger or those cheap quality venom packs .
Low price or swollen lipos are not worth burning a house down.

I charge high quality batts with highest quality thunder Power charger and balancer and still charge in a fire proof container.

Swollen batts scare me after seeing a 5s pack lopo fire in the flying field.








[/quote]

ryan_t888

Swelling packs can be from several reasons,

- Overcharge
- Over Discharge
- Exceeding discharge rate
- Crashing
- Damaged packs
- Trickle Charging Packs
- Unbalanced Packs
- Old packs
- Misuse

Ryan