Time for new batterys

[ridinbikes247]

alright, hers my set up
hot bodies 1/8 truggy with 15/50 gear
2-3300 Mah NiMh battery packs in series
8 XL feigao motor
Mamba Max ESC runs 120 degrees F
motor and batterys run 70 F
i got 6 minutes run time with that set up
I'm aiming for 15-20 minutes run time, is there a way to do it with NiMh..maybe a 5000 Mah venom
If not what type of Lipo should i be on the look out for ? should i run 1 lipo or two ?..i want to stay with Nimh but if i cant get 15-20 minutes out of them i guess ill have to go lipo

[BL_RV0]

run 2 if you can distribute the weight evenly, or one big one, if you have to put it in one location. check out the apogee li-mn 5800 batteries. they're a little pricy, but well worth it. get 2 2s packs ($300) and wire them in series. OR: you could get 2 2s 3800mah packs, sacrifice a little runtime, but have less weight and save yourself $150. do not use 2 3s in series (too much for the mamba max to handle.) i like li-mn because they dont blow up like lipo, and offer the same performance-to-weight ratio that lipo's do. rc-monster carries the 2s packs of both capacities.
personally, i would sacrifice the runtime and get the 3800's because they're half the price, IIRC, about 100g lighter per pack. here is a link to the 2s 3800 packs
http://www.rc-monster.com/proddetail...P3800MN&cat=18
use the normal li-po mode on your charger, charging procedure is exactly the same as li-po, except for the "blow-upping" part.
i definitely recommend li-mn over li-po and ni-mh because they don't blow up and are lightweight. visit
http://pfmdistribution.com/secure/shop/listcats.asp
for all your battery needs. it sounds like i work there
if you only have enough space for one battery, check this one out:
https://pfmdistribution.com/secure/s...d=254&catid=47
if you are nit farmilliar with li-mn and li-po you will need:
1. li-po charger
2. balancer (for as many cells as you're going to run)
3. fan for your mamba max, (they're not supposed to run 4s, but it usually works fine)
4. LVC (low voltage cutoff)
5. BEC (battery eliminator circuit)
i really hope this helps.

[ridinbikes247]

what about like a single 3s or 4s...i already run a receiver pack with the BEC wire cut....would 1 single 3s or 4 s lipo battery get me in the 20 minute range ? plus the same power i have now with the 14.4 volts ?...because i belive a 3s lipo is only like 11.1 and i figured that would be slower than the 14.4 im running now?

[BL_RV0]

read my post. i linked you to a 4s single. do not run a 3s. you will get about 10-12 mins runtime with the 3800's no matter what configuration you use. if your desperate, go for the 5800's and spend 2x the money. 12 cells ni-mh is 14.4 volts, and 4s li-mn is 14.8, or 16.8 when fully charged. 3s would be about the same speed because of the massive decrease in weight.

[ridinbikes247]

i think id be better off just buying two 5000 Mah NiMH for about $100 at my hobby shop. i thought the point of going to lipo is for runtime, but if a 3800 lipo cant give me no more than 10 minutes of run time i think thats a waste of money

[BL_RV0]

y 6 cell ni-mh 3000mah venom pack weighs in at 344g. yours will be slightly heavier because of the extra 300mah, but not by much. my 12 ni-mh cells weigh in at 688 grams. yours, probably around 700-725. the 3s 3800 li-mn weighs in at 350g, saving you ~375g. fully charged, that pack will produce 12.6volts. the 4s li-mn 3800 weighs in at 467g, saving you ~258g.

[ridinbikes247]

but a 3s isnt putting out but 11.1-12.1 volts...will that still out power the 14.4 im throwing at it now ?, im not worried aout weight niether, just backayrd racing ...all i want is 15-20 minute runtime with the same speed i have now

[squeeforever]

Simply disregard the LiMN. There not that great. There way overpriced for what you get. Get some TrueRC packs. I would go with there 8000mah packs. Great packs, and you'll get damn good runtime to boot.

[BL_RV0]

them li-mn's are great. simply disregard sqeeforever. j/k squee, but it was funny.

[highflier]

NMHI will get real heavy if you keep adding more in. LIPO will be expensive, So go for the in between battery. A123!

They are safe, cheap, Super fast charges possible, They are much lighter then NMHI but not as light as Lipo,

Do some math. 16 cell 3300's = 63 watt hours

You could run 5s or maybe 6s A123, Lets assume 5s (18volt) packs to be safe. To get the run time you want you will need 63 X 2.5 watt hours = 157 watt hours
each 5s1p pack will give you 39 watt hours
5s2p = 78
5s3p = 118
5s4p = 157 watt hours. Perfect your run time 15 min.

That will be $200.00 worth of cells, 2 dewalt packs converted.

If it were not for your ESC limits I would really say go 6s3p then your could get a few deep cycles and charge the pack up in 15 min. so you could play as long as you charge!
2 complete sets would give you non-stop play.

Your current pack should weigh about 1.75 lbs
The A123 5s4p pack would weigh 3.75 lbs
However if you say with NMHI 1.75lbs * 2.5 = 4.3 lbs ( in theory)

So that would save you 1/2 lb. on your truck and the pack only cost 200.00 what a steal

Highflier

[highflier]

Opps ignor post above I thought you had 16 cells and I had a math error... I'll repost

A 4s A123 pack would be pefect voltage 14.4 volts
Highflier

[ridinbikes247]

Maxamps Lipo 5000HV 3S 11.1V Pack
or a 3s 11.1v 3700mah LiPo Battery Pack
...would one of thempack give me 15-20 minutes and the same speed as my current set up ?

[highflier]

Do some math. 12 cell 3300's = 47 watt hours
You use 7 watt hours per minute

You could run 4s A123 14.4 volts To get the run time you want you will need 47 X 2.5 watt hours = 117 watt hours
each 4s1p pack will give you 33 watt hours 4.7 min runtime
4s2p = 66 9.4 min run time
4s3p = 99 14.1 min run time
4s4p = 132 watt hrs. 18.8 min run time



That will be $200.00 worth of cells, 2 dewalt packs converted. Plus you will have 4 spare cells

If it were not for your ESC limits I would really say go 6s3p then your could get a few deep cycles and charge the pack up in less 15 min. so you could play as long as you want!
2 complete sets would give you non-stop play.

Your current pack should weigh about 1.75 lbs
The A123 4s4p pack would weigh 3.00 lbs
However if you say with NMHI 1.75lbs * 2.5 = 4.3 lbs ( in theory)

So that would save you 1 1/3 lb. on your truck and the pack only cost 200.00 what a steal


Your 5000 mah NMHI is 72 watt hours or 10 min of run time

End result. build yourself 2 sets of 4s3p packs, you'll run all day and 14+ min per run. All and all you will spend about 300 for the packs. This will weigh just a tad over what you run now!

Highflier

[highflier]

Originally Posted by ridinbikes247

Maxamps Lipo 5000HV 3S 11.1V Pack
or a 3s 11.1v 3700mah LiPo Battery Pack
...would one of thempack give me 15-20 minutes and the same speed as my current set up ?

No,
41 watt hrs /7 = 5.8 min of run time :(

Highflier