Expeertise in lipo'ness needed

[Mansfieldrcsecretary]

Hi there hoping for some opinions on this.
My problem is;
I have a losi scte 3kg short course truck and it is killing batteries. The lipos (5900 lrp, 5000 core rc and 5600 orion) are coming out after a run at 60*c +, swelling and it would appear in danger of death.

I bought a whole new motor and speedo set up, same thing hgappens. The speedo and motor are never above 50*c.
I'm assuming its because of the power draw.
Any ideas or recommendations on cells or mods to improve this.
Cheers

[Nas]

How many amps is the esc or what esc is it?

Sounds like the battery's aren't drawing enough amps for the motor and es.

[CrashBangWallop]

Sounds like the battery's aren't drawing enough amps for the motor and es.[/QUOTE]

2nd from me. If you are running the 'cheapie' 20c 30c packs it's time to upgrade to 60c+ Lipo's.

[Naushad]

Though I'd be surprised if those lips listed are 20-30C

[DCM]

Cheap batteries in a 'not cheap' application, SCTE truck's are heavy and they need cells that can provide the power, obviously yours can't.

[Mansfieldrcsecretary]

Hi there thanks for your help, but I'm usuing LRP 5900 50c/100c cells. They were around £90. Im using lrp x12 motor and hobbywing speedo.

[JCJC]

How long is a 'run' ?

Are there any poor connectors, battery to cable etc

Is there something binding in the drivetrain, without the motor will the car roll freely etc

apart from this I cannot be much help

[Mansfieldrcsecretary]

A run is either 5 or 6 mins, speedo to motor is soldered, well speedo to battery is 4mm gold corallys.
Im pretty sure the problem isnt the connections or equipment, i was wondering if anyone could reccommend some amazing cells.

[Mansfieldrcsecretary]

The transission is as good as a 3100kg, 3 diff, 1mod pitch transmission can be.

[andy-aj]

Are The Batteries fully charged before you use them? What voltage is displayed on your charger, when you start charging back up?

[bigred5765]

what motor and gearing??

[Mansfieldrcsecretary]

cells always fully charged. balance at 4.19v per cell

[JCJC]

I am sorry Mansfieldrcsecretary, I am not up on losi scte 3kg short course trucks (but not much different to the cars we do run I would think), but if your 'runs' were 20 minutes plus I would expect the batteries to get hot, if the connection were poor then the same, when we started we melted Tamiya connectors on what I see now as mild setups.

It seems the batteries are being drained and a lot of power is being pulled from them. When recharged what are the numbers being put back into them ?

[Mansfieldrcsecretary]

Im using stock 40t spur and 12t pinion

[bigred5765]

what wind motor ??
sounds like over gearing to me at the minuet

[Mansfieldrcsecretary]

Typically 2300-2500 mah.

Ive tried 4.5, 5.5 and 7.5 t motors. It happens all the same although, the 7.5 is marginally better at not cooking the cells.

[bigred5765]

well 4.5 5.5 in a truck is over kill and probably the main reaseon youve cooked the cells 7,5 is about right but on 20t /40t even on mod gearing is way over the top from what i can gather,

[JCJC]

What gearing would you suggest Carl, some setups here =

http://www.losi.com/Products/Support...rodID=LOSB0128

15 or 16/40 on fast motors (4.5's top racers) would the surface make a difference, dirt I would have thought easier than grass on the gearing.

[TonyM]

I'm running 5500 Orion 90C in my Durango DESC410R with a 4.5T (4,600KV) motor 12T pinion 54T MOD1 Spur. At the nationals this weekend after 6 minute races the batteries were cool. Re-charge required around 2,800mah.

One thing I did change early on was I was using Core 12WG gauge wire and I noticed this was getting quite hot. I changed all the wiring to 11WG Tekin and now it runs much cooler. As per earlier posts, if the wiring/connections are not up to it then the batteries have to do more work.

[ianjoyner]

Don't most people run the bigger 550 motors? If you're running a 540 (like the X12) then 4.5 - 7.5 does sound a low wind for pulling a big truck, it would certainly draw a lot of current. However if you're managing to damage the batteries I would have thought the motor and speedo would also be very hot.

Has the motor got a lot of cooling? I can't understand how it could be draining enough to cook the batteries without getting hot itself.

2300-2500mAh over 6 minutes isn't a huge amount, the latest batteries should certainly take it.