Batt q,s

[shelby78]

Hey, new member here. Getting back into rc after a break. Last vehicle i ran was a ofna .21 buggy 4-5 years back. I used to race electric long ago and packs i ran back then were sanyo scrc 1700,s and panasonic p170,s (good then)

I,m building a e maxx for a in town\cottage basher. Will be running 8xl, mamba max. I,m kinda a power freak so i,d like to run 5s lipo. I,m only wondering if i go with really good 7 cell packs will i get lipo punch thru the whole pack or only half a pack or so.

I,d already be taking a power cut going with 14 cells vs 5s but if 14 cells will really scream it then i may consider running them. My only prob is for the price 5s isn,t really that much more money than 14 good cells and i know 5s should kick 14 cells any day.

I,m only gonna bash with this and maybe run one race with the nitro guys to try to show up all the revo,s here. Mainly i want some opinions of guys that have ran 5s and 14 good cells and what they can say for power/speed difference. I want alot of power!

I,ve never ran good new packs or lipo just researched alot and watched some vehicles. Thanks for any help.

I already know all the driveline stuff/fans etc etc, I,ve already learned a ton here, thanks.

[glassdoctor]

Welcome!

My rc days date back to racing 1200 cells and dumping in a 4 minute race... :)

I would recomend going lipo... very few people regret doing that. You will get more punch with good lipos.

The weight advantage of lipo is a huge thing imo... esp with the maxx. If you keep the emaxx light then you stand a better chance of not destroying the entire drivetrain. Plus it's easier on the motor/esc.

You can drop in a 12,000mah 4s lipo for the same weight as 14 cells... and the 4s will feel like 14 cells easy. 5s would be much faster imo... although I have not actually run 5s. But I think that's safe to say...

[glassdoctor]

A good choice for your truck would be a pair of 5s 5000mah packs from maxamps... for a total of 5s 10kmah, if you want 5s for sure. But that will be close to the weight of nimh packs. But the runtime and punch will be awesome.

I would just do 4s 8000mah though... (pair of 4s 4000 or 2s 8000... doesn't matter which way) that will save a little weight and they will fit pretty good.

[shelby78]

Your speedy reply is the way i like it :) I can remember guys dumping when running mod class and stop. 3/4 of last lap i would start to dump but it was a small track.

Lipo still has me a bit confused. say i run 4s 6000,s if i went to 4s 12000 power should be the exact same in my mind just longer run time yes? unless the extra mah comes from more p,s giving more amps?

When i look at the higher mah pack the amperage goes up, maybe from the extra p,s in there? is there a line where say 12000 4s could have the power speed of say 5s 4000? (example)

I know old battery stuff so i,m just trying to figure out some of the lipo stuff.

I do know enuff to stay light and all drivline will be upgraded but i got a heavy finger. thanks alot.

[glassdoctor]

You have it right... it's just that the higher mah capacity equals higher amp capability from the battery.

For example... the 12kmah pack will be able to crank out twice the amps as the 6k pack... with the same drop in voltage. This only matters really if/when you are puching the battery near it's limits.

If you parallel nimh packs... run two 14 cell packs together, the same thing would apply: double the runtime and the pack would run cooler and more punchy because it's not working as hard.

And it varies with the brand of battery.. some 3500mah lipos will outperfrom another brand's 6000 or 8000. It's like comparing a GP4300 to a generic crap cell... both are 1.2v but they put out a different amount of power.

You can go really lightweight with a 4s 5000mah pack for example... either from maxamps, kokam, flightpower, thunderpower, tanic... any good brand high rate pack. Just avoid the generic cheapie stuff... definitely stay away from ebay and hongkong shops.

Or you can go bigger and get more runtime... and a little more punch assuming the cells are of the same quality. With really big packs like 10-12k... you can get away with lower rated cells because of the huge capacity.

[glassdoctor]

If you go with a smaller lighter setup, like a 5000mah pack.. you might want to do a single brick pack rather than a two pack setup in the maxx. Just put the pack on the opposite side as the motor and esc... it will make a simpler install etc.