Setup for lipos

[MAXX10]

Hello everyone,
You guys have a very informative forum here.
Right now I have a fairly stock E-maxx, I'm looking for a brushless setup and I was looking at these lipos (http://www.skysharkrc.com/shop/index.php?cat=24&shop=1&) what do you guys think about them? Has anybody ever used them? What about the charger? I would go with (2) FMA scorpions, but I want to go with higher voltage like 22.2 or 29.6 with 2 lipo packs in series.
What are the advantages of running at higher voltage (14.8 vs 22.4)? Efficiency? Runtime? I'm looking for long run-times w/40-50+mph top speed. I am relativly new to this so I hope I'm making sense.

[nl12]

Originally Posted by MAXX10

Hello everyone,
You guys have a very informative forum here.
Right now I have a fairly stock E-maxx, I'm looking for a brushless setup and I was looking at these lipos (http://www.skysharkrc.com/shop/index.php?cat=24&shop=1&) what do you guys think about them? Has anybody ever used them? What about the charger? I would go with (2) FMA scorpions, but I want to go with higher voltage like 22.2 or 29.6 with 2 lipo packs in series.
What are the advantages of running at higher voltage (14.8 vs 22.4)? Efficiency? Runtime? I'm looking for long run-times w/40-50+mph top speed. I am relativly new to this so I hope I'm making sense.

Those look ok I would go with some that are rated 20c continous discharge, since you are familiar with fma, they have a line that is 3200 Mah and 20c discharge they are in the cellpro line, for 6s lipo there are a lot of controlers you can use, when you step it up to 8s lipo there are fewer choices for controlers and they are more expensive. FMA is supposed to be relesing new packs on friday they are 4800mah and 20c continous I will be buying those, I wouldnt be supprised if they lowered the price on their 3200mah cells when the new ones come out if they are more your price range. My understanding is that higher voltage equals higher efficency and higher run time with an appropriatly matched setup. I think 6s lipos should get you 40-50mph, and with a 9xl motor very good runtime you could use a 9920 controler and have an awesome setup for a reasonable price.
ps Hyperion also makes good lipos from what I hear, my opinion is go for 20c they have their own brand charger and balancer, I would get them if I went with hyperion.

[hyperasus]

I think maxamps.com has better bang for buck. Check out the 6000mah packs at maxamps.com.

[coolhandcountry]

With the higher voltage you can run the lower kv motors. Which in turn is going to give you a longer run time and higher efficency.

[MAXX10]

Thanks for the quick responses.
Which controller/motor for 8s lipos?
What's the difference between 20c and 15c as far as power and effects on runtime?
Maxxamps look good, but I wish they had individual cell monitoring. Isn't cell monitoring safer for charging?

[coolhandcountry]

I would say a 12xl wander would work well. The 3695 for a esc. You would need a low voltage cut off. As for the 15c and 20c it would depend on the mah of batteries.

[MAXX10]

Originally Posted by coolhandcountry

f. As for the 15c and 20c it would depend on the mah of batteries.

What if the lipos both had a similar mah rating, how would it effect power/runtime?

Originally Posted by MAXX10

What if the lipos both had a similar mah rating, how would it effect power/runtime?

A 3200 mah lipo with a 15c rating would have a constant discharge rating of 48 amps and one with a 20c discharge rating would have a constant discharge of 64 amps.



formula:
(ah)x(c rating)=(amps)

3200mah 3.2x15(c rating)=48amps
3200mah 3.2x20(c rating)=64amps
4800mah 4.8x15=72amps
4800mah 4.8x20=96amps

Hopefully that makes sense.

[hyperasus]

Originally Posted by MAXX10

I wish they had individual cell monitoring. Isn't cell monitoring safer for charging?

All of maxamps packs come with hyperion plugs now. The hyperion balancer will work with the hyperion charger so it will balance ever cell within .01V of eachother every time you charge. The balancer is $40 and the charger is $85(5 amp charger).

[MAXX10]

Originally Posted by coolhandcountry

I would say a 12xl wander would work well. The 3695 for a esc. You would need a low voltage cut off. As for the 15c and 20c it would depend on the mah of batteries.

What runtime could I expect w/8s 4000mah lipos?
Who makes a good lvc?

Originally Posted by hyperasus

All of maxamps packs come with hyperion plugs now. The hyperion balancer will work with the hyperion charger so it will balance ever cell within .01V of eachother every time you charge. The balancer is $40 and the charger is $85(5 amp charger).

Thanks hyperasus I will look into them. Do you use maxamps lipos?

[coolhandcountry]

Depends on how you run and how you gear it. I would take a guess of about 40 min or better. That is just a guess so please don't hold me to it. I was getting 25 -30 min on a 9xl and 3700 nimhs 18cells.

http://66.241.195.91/lithium/lithium.asp?path1=lithium

Mike said something about getting these in. I don't know if he did.

[MetalMan]

If you go Maxamps, I would suggest against the packs with 2100mah cells. Many airplane guys liked the performance of them, but after about 30 cycles the packs had a dramatic drop in performance.

Another site for Lipos is this one:
http://www.commonsenserc.com/index.php?cPath=37 Their prices are good, and as far as I have heard their packs aren't bad at all.
I myself am particularly interested in these packs (for paralleling and putting in series):
http://www.commonsenserc.com/index.php?cPath=37_35

[MAXX10]

I think I am going 6s lipo for now. What should I go with for esc/motor? 9920?
Bk electronics X & XL motors appear to be out of stock, how do lehner compare?

[hyperasus]

BK 10XL is in stock.

[coolhandcountry]

The lehners are great quality. They seem to produce more power, more run time, and stays cooler. They do cost more money though. If you want a lehner i would suggest a 1950 7 turn. 6s lipo would be a great combo. With a 4000 mah lipo i would say about a 20 min runtime or so.