4s 8000 lipo what brand?

[lincpimp]

If you want to squeeze every little bit of runtime use a 3v per cell setting.

[superek4]

3v will my cells get damage?

[superek4]

Originally Posted by superek4

ok, i hv previous record of my last race i charged my batts n it ended at 3380, i estimated i hv ran for 20-21mins so izzit 3380/21mins? =161mah per min?

i had 12pinion at 50spur with 1600kv motor so what batts i need to do 30min?

izzit 161mah/per min x 30mins?= 4830mah i need to run a 30min race?

if i am going to run at 13pinion do i need more mah?

Anyone?

[hemiblas]

3V should be fine but 3.2V is better as everyone has montioned. As the linc says at 3v you will squeeze a bit more runtime out of the pack as the cutoff will get hit later. Easy way to figure runtime is 4sx8k =32 6sx5k = 30. 32 is greater than 30 so its more runtime. You have 4 8000mah cells vs 6 5000mah cells.

[littlegiant]

Originally Posted by nitrostarter

I'm a working, broke student that plays with multiple r/c's....

You are broke because you have multiple RCs. :D

[Patrick]

Originally Posted by superek4

ok, i hv previous record of my last race i charged my batts n it ended at 3380, i estimated i hv ran for 20-21mins so izzit 3380/21mins? =161mah per min?

i had 12pinion at 50spur with 1600kv motor so what batts i need to do 30min?

izzit 161mah/per min x 30mins?= 4830mah i need to run a 30min race?

if i am going to run at 13pinion do i need more mah?

Are you talking about 4s, 5s or 6s? I assuming 6s to get amp draw that low.
From that amp draw it does look like a 5000 mah pack would do about 31 minutes. You would need to use about 107 watt hours to do 30 minutes. Personally I would like to have a little bit extra to make it safely (hitting LVC in the last couple of minutes is not fun) and to not stress the pack so much.They don't like having the last 15% or so taking out of them too often. Is there any of the 5400-5500mah packs that would fit? 6000 mah would be good, but is pretty heavy.

My old true rc 5s 8000mah pack (148 watt hours) with 1515 2.5d (1650kv) setup would do just over 30 minutes racing when the pack was new, but it lost its capacity fairly quickly once a few cells stopped holding voltage. I only got about 5 or 6 months from that pack, but it did do all of my racing and bashing for that time.

SMC has 9000mah 2s packs (4s would be 133 watt hours) http://www.specpointbatteries.com/in...p?productID=86 But 4s on that motor wouldn't be the best setup, and 6s 9000mah would be over kill.

[superek4]

Hi, yes it's a 6s 5000@25c I can't get any higher Mah unless maxamps or truerc 4s 8000 but only 10c

I m racing dun bash much, I hv 4s 5000 to bash.

I use 4s 4100 to race as it's 30c n limited run time.

But strange is using my 4s 4100 my per min Mah draw is abt 250 n it's only 7mins may I know y?

[Patrick]

Originally Posted by superek4

Hi, yes it's a 6s 5000@25c I can't get any higher Mah unless maxamps or truerc 4s 8000 but only 10c

I m racing dun bash much, I hv 4s 5000 to bash.

I use 4s 4100 to race as it's 30c n limited run time.

But strange is using my 4s 4100 my per min Mah draw is abt 250 n it's only 7mins may I know y?

What are you talking about? What is 7 minutes?

[superek4]

My heats is 7min, I used a 4s 4100 lipo n d per min amp draw was abt 250 abt 100mah more than my 6 may i knw y?

[Patrick]

Have you read everything people have said about total watts being most important to runtime and power output, not amps or volts by themselves?
I guess I'll explain it again. 6s has 50% more voltage than 4s, so to have the same power output on 4s you need 50% more amps.
Example for 6s, 22.2 volts X 10 amps will be 222 watts
on 4s, 14.8 volts X 15 amps = 222 watts. An extra 5 amps to make the same power.
That means a 4s setup should draw 50% more mah per minute than an 6s setup of the same speed and power.
Your 6s current draw you say was 160 mah per minute, so 50% will be 80 mah.
160 + 80 = 240 mah per minute for a 4s setup of the same speed and power, which is pretty close to the 250 mahs that you got. Now you have seen the real world difference between high and low voltage that people have been talking about all this time.

[superek4]

Damn now I get it thx

Originally Posted by Patrick

Have you read everything people have said about total watts being most important to runtime and power output, not amps or volts by themselves?
I guess I'll explain it again. 6s has 50% more voltage than 4s, so to have the same power output on 4s you need 50% more amps.
Example for 6s, 22.2 volts X 10 amps will be 222 watts
on 4s, 14.8 volts X 15 amps = 222 watts. An extra 5 amps to make the same power.
That means a 4s setup should draw 50% more mah per minute than an 6s setup of the same speed and power.
Your 6s current draw you say was 160 mah per minute, so 50% will be 80 mah.
160 + 80 = 240 mah per minute for a 4s setup of the same speed and power, which is pretty close to the 250 mahs that you got. Now you have seen the real world difference between high and low voltage that people have been talking about all this time.

[superek4]

i ran today at my local race track 50/13pinion with 1600kv & 6s 5000 finished at 24mins now charging the batt to find how much mah used

[superek4]

Originally Posted by Patrick

Are you talking about 4s, 5s or 6s? I assuming 6s to get amp draw that low.
From that amp draw it does look like a 5000 mah pack would do about 31 minutes. You would need to use about 107 watt hours to do 30 minutes. Personally I would like to have a little bit extra to make it safely (hitting LVC in the last couple of minutes is not fun) and to not stress the pack so much.They don't like having the last 15% or so taking out of them too often. Is there any of the 5400-5500mah packs that would fit? 6000 mah would be good, but is pretty heavy.

My old true rc 5s 8000mah pack (148 watt hours) with 1515 2.5d (1650kv) setup would do just over 30 minutes racing when the pack was new, but it lost its capacity fairly quickly once a few cells stopped holding voltage. I only got about 5 or 6 months from that pack, but it did do all of my racing and bashing for that time.

SMC has 9000mah 2s packs (4s would be 133 watt hours) http://www.specpointbatteries.com/in...p?productID=86 But 4s on that motor wouldn't be the best setup, and 6s 9000mah would be over kill.

i found this any good? much cheaper than maxamps

http://www.hobbycity.com/hobbycity/s...idproduct=6325

[Patrick]

Originally Posted by superek4

i found this any good? much cheaper than maxamps

http://www.hobbycity.com/hobbycity/s...idproduct=6325

Yes, Polyquest is usually pretty good. Same pack cmcckive linked to in post #4.

Originally Posted by cmcclive

4s 8000mah batteries are not going to provide much more runtime then the 6s 5000mah.
(assume 3.7V per cell "nominal" voltage then 4x3.7Vx8A-h= 118.4Watt-hr
and 6x3.7Vx5A-h=111Watt-hr, only a 6.7% increase in storage)
They end up weight about the same because the store about the same amount of power...

what size battery area do you have to work with? could you put the pack(s) on their side to increase size? (aka do you have the height available). Any pics of your setup?

If you can fit it Mike has a 6s 6000mah battery for $309, my rough estimate is it should give you 30% more runtime (due to more stored capacity). It is pretty sizable though.... 168 x 48.5 x 66.5 mm

here is the link http://www.rc-monster.com/proddetail...pq25c6s6000mah

BTW if any of the battery Gurus disagree with my math/reasoning, please correct it. Thanks

[superek4]

will this 6s 6000 able to finish a 30min main? i need to lighten my crt, it weights a ton