want to buy Lipos
 

A lil help please...

Im looking for someone to just tell me what to purchase. This is my set up and I want to make the move to Lipos.

Im running a 9xl, 9920 esc, 51 spur, 16/18/20t pinions, strobe slipper, single speed tranny, UE 8 spyders and 4300Mah 16 cells packs
http://i71.photobucket.com/albums/i1...e/P1010331.jpg

I of course don't want to lose any power (more power if possible) and want long run times. Which complete charging set up do I want? I have a Super brain 977 now, but if there is a dummy proof charger available for Lipos just say so :yes:

Thanks in advance...

How many volts can the system handle.

Jason

Topic moved to brushless;

With that warrior controller, you do need to use a seperate LVC (a device that monitors the voltage of the pack, lipo's can't go bellow 3V) the BK controller hasn't got a one build in.

You could go up to 5S with that system, 6S would be pushing it. The controller can handle it, but the motor will run a tad hot for my likings.

Right now that is about 19.2 volts, and since you said that you wouldn't mind more power, I'd get two 3s 8000mAH packs (one on each side) and wire them in series. There is a new Hyperion charger also that is supposed to be very good, and also has a built in balancer which is a nice feature.
http://www.maxamps.com/Lipo-8000-111-Pack.htm
http://www.maxamps.com/EOS0610i.htm

Edit: As serum said, 6s would be pushing it a little, but I thought I'd mention it since you said you wouldn't mind more power. I only linked to Max Amps packs because the topic was originally in their section. But there are better lipo's available....

With good lipo's the power will increase, as well as the power/weight ratio (the vehicle will be lighter and the packs will deliver more punch) 5S quality lipo's will be more peppy than 16 NIMH cells.

Good cells hold their voltage better under load;

What is your budget?

the esc can handle up to 6s lipos, so for more power you can run two 3s packs in series. A 5s pack would be similar to what you are running now, since the reduced weight should off set the slight loss in voltage.

Your current charge can handle up to 3s lipo packs, so you can stick with your charger, but you'll be pushing its upper limits. Check out any of the chargers in the rcm store, or the new hyperion chargers at maxamps.

edit: (ya'll are quick.... I type too slow). my post is an echo of the two above.

Check out the TrueRc. The 8000mah 3s and 2s packs on this page are great for the money. Ive beeen using them for quite a while and for the price they are unbeatable IMO.

http://home.comcast.net/~truerc/read...eady_packs.htm

As for a charger. I like the Super Brain 989 for value to performance. The 977 you have will work, but it will only charge the 2s pack at 3 amps and the 3s packs a 2.5 amps. that means about 2.5 - 3 hours to charge a pack, but you can charge 2 at a time.

If you do go to 6s on the 9920 and the 9xl make sure you drop your gearing a few teeth to keep the temps in check. I really think you will notice a huge difference just by going to 5s from the NiMH you have been running.

TBH the problem with trurc cells is that you need a lot of MAH to get the current output you need which ends up with an much heavier and less agile vehicle.

personally i would rather get two 5000mah 3s 25c enerland packs at 389g each than the 8000mah 565g packs.

Thats 352grams more weight which is higher up raising your COG also 352 grams more weight that has to be lugged around reducing acceleration plus adding more strain to the brushless motor and controller and the transmission.

Enerland cells are better quality meaning they will likely have a better cycle life than truerc cells.

I hear you on the weight thing, but it one of the key things he was looking for was "long runtime." Big packs give long run times.

If long run time is the goal why pay for the extra C rating you dont need. The big packs give you the power you need and the runtime.

As for life cycle of the TrueRC. I have an couple old packs that are at least a coule years old now and have hundereds of cycles on them. Still going strong.

I have enerland packs as well and love them and for racing I agree that a smaller, lighter pack is more ideal. For long bash sessions the TrueRC packs are perfect.

I run a very similar combo to you and will say that the 9xl is very happy on 5s. The true rc lipos (8000mah ) will give you good runtime, I guess you would have a pair of 5s 4000 lipos wired in parallel to make 8000? or a 2s and 3s 8000 packs wired in series to make up 5s 8000mah? Same think either way. I acutrally run a pair of the hextronic 2200 mah 5s lipos from united hobbies. They are underrated at 2200 mah, and they run super cool and do not take much in the way of balancing to be even after a hard run.

The mrc 989 is an excellent charger, I have 1 and it is great, I would highly recommend it!

Btw; fitting 5S packs underneath your motorplate might be a pita, check the height you have before buying the packs. I know the FLM chassis don't have much clearance underneath the motor.

Ok, this is what I'm reading and understanding.

First, which LVC should I get with my setup?

About the chargers. I thought i read awhile back the Brain 977 had problems with false peaking etc. True ?? Should I just get the newer brain or is there a better Lipo charger available like th Hyperion. I like the built in balancer idea.

Next, the 5S lipos sound good. The 6S lipos sound even better, but I don't want to push it.
I read get good brand Lipos. The two brands mentioned are TrueRc and Enerland. Is one better then the other or is it all opinion? If I spending the money I would like to get a top end brand. The money really isn't an issue.

I have two more short questions. Can you guys guess an approximate run time with 5S 8000mah batteries. I know it depends how I drive the truck, but just a guess would be cool.

And finally... will this new set up smoke on of those new 16.8 volt e-maxx. I kinda think (would hope) my current set up will, but I wanna make sure :wink:

:lol:Yes. It will SMOKE the new stock emaxx.


As far as lipos go. You can go with higher quality packs (enerland) and then you can run smaller capacities cuz they will be capable of putting out the amps that your system will draw. But, the smaller packs will provide shorter run times.

The lower capability packs (TrueRC) require them to be a higher capacity to make them capable of delivering the amp output you want. This will deliver the longer run time and be capable of delivering the current you need. But, the bigger packs weigh more. More weight can cause more strain on the drive train and such.