long lost newbie lipo questions

[andrewhendler]

this is more or less a question about what you guys are running. Its been almost a year since i was on here and no one was running lipos yet.
I run them in my planes and plan on getting back into crawling here soon but dont know what you guys are running. Like what kinda amps are you pulling with a 55t motor on a 1/10 running a 15c 11.1 2000, ect,ect,ect

[slobin3d]

I've seen 55t run on 7.4 1400's, I run a 3 cell 2100 gen 3 thunder power, w/ a mamba max and hyperion 2013 outrunner

[Racer4Life]

20c 1550 Mah 2C lipo

Going to try a 20c 2200 Mah 3C soon.

Seem most of the guys are running the 3C lipos to help with wheelspeed.

[andrewhendler]

outrunners hey. No s&%t, i have tons of them for my planes. Are the higher turn low KVs better, I have a 30 turn 980kv laying around somewhere that will probably put out some monster torque. Also how does the higher c rating or the ability to draw more amps help you guys?

[Calderwood]

Originally Posted by Racer4Life

20c 1550 Mah 2s lipo

Going to try a 20c 2200 Mah 3s soon.

Seem most of the guys are running the 3s lipos to help with wheelspeed.

I fixed your post for you...

[racerx]

Been running 3s lipos in 2.2 and super for about a year and a half. No other choice in my book!

[andrewhendler]

Nice! I only have about 7 3s lipos sitting around the house
That will be good for what, maybe 15 hours of run time.

[JAM MaxAmps.com]

I ran the Data Logger yesterday with a Holmes Hobbies Crawlmaster Sport Outrunner powered by our new 860 11.1 volt saddle pack and under a high load I only peaked at a 14 amp draw. Crawlers don't hit high amp loads like Planes and off-road cars/trucks. Small packs are working well.

Here's a post from Chapter 3 of what you can do with an AX-10:

Now that you have these simple easy upgrades done it's time to add a Nice Neat little Li-Po Saddle pack to those brand new TCS battery plates. We at MaxAmps.com can make just about any battery pack you need. I had the guys make me an 860 Mah saddle pack from two 430 3 cell packs and it's perfect. If you'd like one of these just request that it's made with smaller gauge wire such as 18 Awg this will ensure that the pack fits under the servo plate and between the King pin pivot and the axle pumpkin. It's a great pack and offers a different option than the 6 cell 2/3rds saddle packs. Just remember if you need smoething you don't see on the website call us and chances are we can make it for you.


I'd like to thank Matt at Axial and Kevin at TCS for the help and stay tuned for Chapter 4 coming real soon.


Jason

Here the latest info on the packs:
$51.99 same as the brick format on the website. For now, they can order that pack and put a note they want it in saddle format with 18AWG wire. It should be up on the wesite Friday under the Axial Packs.

Attached Thumbnails

[Racer4Life]

Nice looking packs. They look like they fit great!

I know, I know...us guys are never happy....Can you take a shot of those on some TLT axles?

[andrewhendler]

wow, thats excessivly small. How long of run times are you guys getting with your 800's. I have a 900 but most of mine are 1400s which are small enough for me

[EeePee]

Originally Posted by Racer4Life

Can you take a shot of those on some TLT axles?

Don't think they'll fit.

[JAM MaxAmps.com]

Thanks EeePee but like I said they are perfect for the Axial axle with the TCS plates. And guess what they are on the site, you can see the pack here. http://www.maxamps.com/proddetail.ph...le-Pack&cat=82

jason

[andrewhendler]

Hey Jason,

Nice to see some much support from so many different companies on this site. You guys did alot for us so far at rumrunners.

So on a 2.2 rig your pulling about 15 amps max on a 3s setup with about a 400 size outrunner. Are you guys using higher turn motors, also are you getting the same run time?

[JohnRobHolmes]

What voltage did the pack dip to at 14 amps Jason?

I have stalled my crawlmasters at over 100 amps on just 8.4v nominal, but the battery has to deliver before the motor can take. Crawling will burst some big amperage with the right motor, ESC, and battery combo.

[Reflection]

John,how many amps do you think my Crawlmaster was pulling when it stalled and started smoking last weekend? I was running a freshly peaked 2100 3 cell.

Wish I had something to test with.

[andrewhendler]

What packs where you running to pull 100amps with only 8 volts. They have to be some high discharge batts, Are you running a watts up to pull these #'s john

[JohnRobHolmes]

I was using a 7 cell gp 3700 pack and mamba max ESC for the burst test, sampling rate set to 40hz. I believe it is called a BNB data logger. Now I have a Eagletree v3 logger which only has a 10hz sample rate, so it will not see the larger and faster bursts, but will still see decent bursts. The Watts UP meter is pretty useless to see any bursts, it averages about once per second (1 hz sample rate) if I remember right.

Raptor, the crawlmaster might have been pulling a large amount of amperage when it smoked. Overheating will break down the epoxy on the windings and it will turn into a big dead short. The lipo battery and ESC become the limiting factor on amp draw. Good sub-C will generally discharge at 30C burst for a few seconds, 2/3A is around the same. A 2100 Enerland lipo is generally 12-15C continuous rated depending on the quality of cell. The vislero (Enerland) 2100 packs will burst 35-40 amps for a split second and handle 12C continuous on average.

The big question with any cell is the voltage at a finite amp draw. Mah (milliamp/Hour) is a poor way to rate a cell IMO. I prefer the Watt/hour to see the real capacity. It takes into account the voltage over the life of the pack. Although a lipo may be rated at 11.1V, all lipo cells are not created equal and there are many manufacturers.

[andrewhendler]

Originally Posted by JohnRobHolmes

Although a lipo may be rated at 11.1V, all lipo cells are not created equal and there are many manufacturers.

amen to that. Also going off of manufacturers c rating, especially with untested packs is not very reliable as well.

[andrewhendler]

Also no one responded to run times with lipos yet

[JohnRobHolmes]

Originally Posted by andrewhendler

Also no one responded to run times with lipos yet

2100mah is 2100 mah. It doesn't depend on whether it is lipo or nimh. I get about an hour to an hour and a half with a 3 cell 2100 pack while tooling around with a 1.9 rig. I would get more runtime if it was a 2 cell pack, with everything else unchanged on the vehicle. Lower voltage = lower amperage on any given electronic setup.

In a 2.2 comp situation I may only get 45 minutes on the same 2100 pack.