Flightmax 5000 20c lipos - RC-Monster Forums

lucias · **Flightmax 5000 20c lipos -** 12.28.2010, 12:58 PM

I am getting one of the two fluxes I bought today.. Super excited to drive it but I was reading and it says not to use lipos under 25c rating.. I have some Flightmax 5000 20c lipos laying around I wanted to use in them... will they hurt the speed controller by using them?

josh9mille · 12.28.2010, 02:48 PM

I wouldnt chance it.

mac3194 · 12.28.2010, 03:55 PM

i was using 2s and 3s zippy 5000mah 20c's for about 3 months while i had a flux and they did perfectly fine with ambient temps and no problems from the esc.

lucias · 12.28.2010, 04:09 PM

Why would they have that warning on it? would it pull to much current for the battery?? I just thought it wouldn't have the punch as much as the higher rated batteries..

Bondonutz · 04:31 PM

If you bump the gearing down a little from what ever stock is and moniter temps of the packs you might be just fine, Use due care untill you get a handle on how they perform.

mac3194 · 12.28.2010, 04:26 PM

I think they just want u to be able to get there advertised speed and performance but i dnt think u will have any problems with those batteries.

sandblaster · 12.28.2010, 05:44 PM

Hope you have a deep pocket for replacement electronics. Learned from experience with the 20c. Run 40c now, got rid of all my 20c. Believe what HPI says about c ratings. The 40c are great batteries.

lincpimp · 12.28.2010, 05:53 PM

I would not chance it myself. Best case is you cook the lipos, worst case is they fry the esc and cook... I would go for the new flightmaxx 40c 5000mah lipos, I have a 6s pack of them that I run in my lst and they are some of the best lipos I have owned.

jhautz · 12.28.2010, 06:02 PM

Quote:

Originally Posted by lucias

I am getting one of the two fluxes I bought today.. Super excited to drive it but I was reading and it says not to use lipos under 25c rating.. I have some Flightmax 5000 20c lipos laying around I wanted to use in them... will they hurt the speed controller by using them?

SO... you can use 25C rated 1000mah packs then? Thats a BS rating IMO. They need to specify a minimum constant/burst amp capacity. Not a C rating. I could put 25c 1000mah packs in there and it would be way worse for the esc than the 20c 5000mah packs you are talking about.

I remember reading somewhere saying that CC didn't want people to use packs with less than 100 amps constant amp capability or something like that. The issue was ripple current from batteries that didn't have the ability to maintain voltage under load causing the esc to fry. I don't think you have to worry about cooking the lipos as long as you pay a little attention to the battery temps.

Like others have said. Put a little punch control on the esc or gear down and you should be fine with the packs you have for a little while at least.

_dV · 10:09 PM

jhautz has it right. The C rating by itself doesn't tell you much. Multiply the C rating by the mAh capacity/1000 to get the output current rating. So 20C x 5000mAh/1000 = 100 amps constant output. This seems too low for a flux IMO. You could try punch control etc but with Turnigy\Flightmax packs being so cheap just buy some packs with better current output instead of risking it.

josh9mille · 12.29.2010, 09:21 PM

Quote:

Originally Posted by jhautz

SO... you can use 25C rated 1000mah packs then? Thats a BS rating IMO. They need to specify a minimum constant/burst amp capacity. Not a C rating. I could put 25c 1000mah packs in there and it would be way worse for the esc than the 20c 5000mah packs you are talking about.

I remember reading somewhere saying that CC didn't want people to use packs with less than 100 amps constant amp capability or something like that. The issue was ripple current from batteries that didn't have the ability to maintain voltage under load causing the esc to fry. I don't think you have to worry about cooking the lipos as long as you pay a little attention to the battery temps.

Like others have said. Put a little punch control on the esc or gear down and you should be fine with the packs you have for a little while at least.

Ya thats a point, but honestly who uses anything less than 5000mah in a monster truck anyway?

lincpimp · 12.30.2010, 12:55 AM

Quote:

Originally Posted by josh9mille

Ya thats a point, but honestly who uses anything less than 5000mah in a monster truck anyway?

Depends on the voltage. If you were looking for the same total output (watts) a 5000mah 6s pack would work as well as a 12s 2500mah pack...

And weigh the same. Size might be a limiting factor, unless the 2500 mah cells were slimmer, but given the same C ratings the cells are often about the same thickness, just smaller in other dimensions.

_dV · 01:59 AM

Yes, unfortunately it's not wise to try and generalize as there are technical concepts that should be understood. As per lincpimp I run a 4000mAh 6S in my truck atm which gives me similar run time to what a 6000mAh 4s would as the 6S pack can deliver 50% more energy per second per amp than the 4S due to higher voltage. Good old P=VI. The 6S pack is 40C giving an amp output of 160 which is fine.

Generally it's best to figure out the amp rating for a pack and make sure its a bit over what you need to give some breathing space for various things.