DJI S800 batteries

damienpdoyle

damienpdoyle

Member
Hi all
I am only new so sorry if if questions is silly.
I am planning on buying a S800 from DJI. The information I have read tells me I can use 6S batteries from 10000mah to 15000mah. I know I can install 2x 500omah batteries in parallel giving me a total of 10000mah.
am I able to install 3x 5000mah batteries in parallel?
The other questions is besides weight is there a problem to install 2x 9000amh in parallel?
 

V

vislaw

Member
You can run as many 6S as you want in parallel as the voltage will stay constant. HOWEVER, the takeoff weight limit is 7kg so you will quickly get overweight if you start stacking too many batteries. I mainly use MaxAmps 11,000 LiPos because they have the best power to weight ratio, but I have also flown two Turnigy 8000 batteries in parallel when I am not flying the Zenmuse. You will be fine with two 9000mah as long as you are not overweight.
 


S

suddenincline

Member
just my two cents...I fly with two 5000mah batteries and the reason for this is peace of mind...I had one battery have a cell decide to go out and the other battery was able to make up the difference to land the s800 with out crashing but even at full stick it was descending faster than normal this tells me if a cell goes out while flying single battery it's coming down to fast...jmo tho
 

C

Chris98

Member
You can stack up on the thunder power ms ( military spec) batt they are light enough to series and parallel and keep the weight low its not far fetch to put 4 x8000 mah 6s batteries check it out 30 min
 



K

ksrimoungchanh

Member
@Chris98,

I have always flown fully loaded S800/Zen/Retracts/2 8000 Nanotechs flight Batteries and another smaller 3S for retracts and VTX: my concern goes beyond power capacity. I always notice the motors get much more hotter depends on the load. I can get about 7-10 mins, but I normally land and let that S800 rest, due to the heat that comes from the motors.

I have 2 S800 fully loaded, so I will take the second one up while I rest the first. (I have not tried pushing beyond 15mins loaded), I would be worried that the heat on the motor my cause others issues in the air. I don't believe it will be worth that extra 10mins to put the craft and payload at risk, and potentially ground people/object. Most of my flights are planned and shot twice.. once from each s800 then we move on.. if not, by the second S800 landing, the first is cool enough for me to feel comfortable to launch it again and trying for that same shot.

I saw the DJI test with several S800 naked, tethered and flying for quite some time. But I would think that no load would produce less heat. I presume the outside (environment) would also have an hand in motor heat/performance. I in a 80F-100F ambient outside environment.

I am looking for longer flight time like everyone, but wonder if I am the only one stuck on the motor heating.

What are your thoughts on motor heat?

KS
 

maxwelltub

maxwelltub

Member
Those 8000 nano techs seem too heavy to have two in parallel. It sounds like your motors are getting hot because your rig is too heavy.
 

K

ksrimoungchanh

Member
true.. but Chris98 says:

"You can stack up on the thunder power ms ( military spec) batt they are light enough to series and parallel and keep the weight low its not far fetch to put 4 x8000 mah 6s batteries check it out 30 min"

how much will 4X 8000 MS weigh? Can't be that much to have normal heat at 30mins even without the Zen.

That is my point though.. 4x8000 gotta come close to that lift off limit too. am I wrong. I could not find any spec on the MS batteries.. any direct links?

Not to mention, the ESC is open a vulnerable surface. see posting: #7915 another pilot with less weight then mine got hit with electronic issues before battery source ran out.

http://www.rcgroups.com/forums/showthread.php?t=1677105&page=528

I just wanted to help the initial poster of this thread to consider other components while looking for longer power source. I believe most of the S800 dropping has dropped with lots of power left in the pack.


KS
 
Last edited by a moderator:

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Dantallus

Member
Certainly would agree with running 2 of the 3 S's in series as mentioned above to save the craft if you drop a cell. Having an extra battery in parallel isn't going to double flight time anyway. At most it's a 40% to 50% reserve to get the get the rig back on the ground safely if you stay on station a bit longer than you plan working a shot.
 

D

deluge2

Member
I don't think I've ever seen a recommendation to run two 3s batteries in series for the s800. Of course that would work, in that it creates a 6s power source, but it adds weight and extra connector failure points without and compensatory redundancy. Can't really see any advantage to that setup vs two 6s cells with half the capacity, maybe I'm missing something?

Steve

Dantallus said:
Certainly would agree with running 2 of the 3 S's in series as mentioned above to save the craft if you drop a cell. Having an extra battery in parallel isn't going to double flight time anyway. At most it's a 40% to 50% reserve to get the get the rig back on the ground safely if you stay on station a bit longer than you plan working a shot.
Click to expand...
 

R

Rainman

Member
Dantallus said:
Certainly would agree with running 2 of the 3 S's in series as mentioned above to save the craft if you drop a cell. Having an extra battery in parallel isn't going to double flight time anyway. At most it's a 40% to 50% reserve to get the get the rig back on the ground safely if you stay on station a bit longer than you plan working a shot.
Click to expand...

As has been said, I wouldn't recommend running 2 x 3S in series to get a 6S solution, because if a cell goes out of whack you have no idea what the impact would be. I've seen packs with a cell fail that goes open circuit, which means it doesn't matter how many you connect in series because you loose the whole pack. You got NO redundancy with anything connected in series. Also, if one cells goes low voltage then the draw on the remaining set in series goes through the roof, meaning that if you're still flying then the chance of the remainder of the series array failing increases significantly. There is literally no advantages to connecting packs in series except for saving pennies whilst maybe being able to use the 3S packs for other things, but doing that compromises your 6S solution too because they will be so out of balance when you recombined them it would be pretty reckless.

Connecting 6S packs in parallel is a way more sensible option to gain capacity and resilience. Of course you won't double the flight time, but you will extend it to some degree and it depends as to just where you are on the efficiency curve when you started out with a single pack. There is always a sweet spot based on your choice of combined packs, their combined weight and your resultant take off weight.
 

gtranquilla

gtranquilla

RadioActive
Just get familiar with and use eCalc for Multirotors to determine the "sweet spots" for your battery capacity..... either one large capacity single battery or parallel sets of 1/2 total maH capacity. All the other methods are simply personal preference and/or speculation.
damienpdoyle said:
Hi all
I am only new so sorry if if questions is silly.
I am planning on buying a S800 from DJI. The information I have read tells me I can use 6S batteries from 10000mah to 15000mah. I know I can install 2x 500omah batteries in parallel giving me a total of 10000mah.
am I able to install 3x 5000mah batteries in parallel?
The other questions is besides weight is there a problem to install 2x 9000amh in parallel?
Click to expand...
 


soler

soler

Member
Hi Rainman,

How is a 6S any different to 2 x 3S connected in series, the only difference I see is that the manufacture configured the 6S while the user configured the 2x 3S, there are the obvious issues with the additional connectors but what else?

Thanks

Rainman said:
As has been said, I wouldn't recommend running 2 x 3S in series to get a 6S solution, because if a cell goes out of whack you have no idea what the impact would be. I've seen packs with a cell fail that goes open circuit, which means it doesn't matter how many you connect in series because you loose the whole pack. You got NO redundancy with anything connected in series. Also, if one cells goes low voltage then the draw on the remaining set in series goes through the roof, meaning that if you're still flying then the chance of the remainder of the series array failing increases significantly. There is literally no advantages to connecting packs in series except for saving pennies whilst maybe being able to use the 3S packs for other things, but doing that compromises your 6S solution too because they will be so out of balance when you recombined them it would be pretty reckless.

Connecting 6S packs in parallel is a way more sensible option to gain capacity and resilience. Of course you won't double the flight time, but you will extend it to some degree and it depends as to just where you are on the efficiency curve when you started out with a single pack. There is always a sweet spot based on your choice of combined packs, their combined weight and your resultant take off weight.
Click to expand...
 

C

Chris98

Member
Ok all the lipos that are 6s are in a series configuration. most often two 3s, this is for your c rating and your 22.2 voltage.Parallel controls your hours that are rated in mili amps. the more mah you have the more time you can fly theoretically but the heavier you are the more juice it will drain to keep you up so you can loose time if you are heavy Ps if you have 2 11.1v 5000 mah 3s batteries and you series them out you will have 22.2 v 5000 mah batteries you will have to do the same configuration again and parralel all four batts to get 10000 mah
 

C

Chris98

Member
Slight correction if you didn't understand me when I say all four batts I mean series the two than series the other two you will have two 22.2 5000 mah batteries then parallel the two batts but technically it's four batteries
 

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