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-   -   Expeertise in lipo'ness needed (http://www.oople.com/forums/showthread.php?t=103685)

Mansfieldrcsecretary 17-06-2012 10:54 PM

Expeertise in lipo'ness needed
 
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 17-06-2012 11:14 PM

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 17-06-2012 11:26 PM

Li-po's
 
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 17-06-2012 11:30 PM

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

DCM 18-06-2012 06:09 AM

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 18-06-2012 08:25 PM

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 18-06-2012 08:33 PM

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 18-06-2012 08:53 PM

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 18-06-2012 08:56 PM

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

andy-aj 18-06-2012 09:14 PM

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

bigred5765 18-06-2012 09:21 PM

what motor and gearing??

Mansfieldrcsecretary 18-06-2012 09:32 PM

cells always fully charged. balance at 4.19v per cell

JCJC 18-06-2012 09:37 PM

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 18-06-2012 09:39 PM

Im using stock 40t spur and 12t pinion

bigred5765 18-06-2012 09:42 PM

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

Mansfieldrcsecretary 18-06-2012 10:50 PM

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 18-06-2012 11:34 PM

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 19-06-2012 07:38 AM

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 19-06-2012 08:06 AM

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 19-06-2012 11:34 AM

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.


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