How to run multiple batteries on a quad

[darowden]

Whether for weight distribution, or longer time/range, what is the best way to do this?

Series or parallel? Obviously the batteries would all have to be he same voltage but what about discharge (C rating) and mAh ratings, would they need to be identical also?

any pros and cons here? Does anyone make a harness specifically for this type of setup?


Thanks for any ideas.

 

[Efliernz]

Welcome to the forum darowdon

The batteries need to be the same number of cells and the same capacity - connected in parallel and of similar performance. red to red, black to black. Ideally identical batteries to ensure they work together evenly.

View attachment 17939

The copter will draw the current evenly from each pack. If they are different capacities, one pack will run out before the next.

2 x 3S 2200mA packs = 3S 4400mA packs. You don't get quite twice the running time because you add the weight of the extra pack. If you keep adding packs, it gets to the stage where you are only adding a pack to be able to carry another pack without any duration benefit!

Also - my "performance" comment. A lipo will reduce in performance over time and it. A new pack sit at 3.9v for most of it's use, an old pack 3.7. Because of this, it is advisable to use batteries of similar performance or history...

I hope that helps.

Pete

 

[darowden]

Thanks for the info!

Now I just need to find a harness that can do this.

Do you know where that adapter that is in the image you posted can be purchased?

 

[Efliernz]

Depends on what connectors you use! I make mine

 

[darowden]

XT-60. I found the harness on ebay, and also the EC3 to XT-60 adapter needed.

Thanks for pointing me in the right direction. I would make my own, but I don't trust my soldering. Maybe when I get a better iron and soldering jig.

 

[Efliernz]

To do connectors, you really need a 50W minimum iron and a wet cloth to take the heat away once soldered

 

[haha49]

I've done 2 packs before you just buy the wire or make a conector or wire and hook them up. Make sure they're both at the same level or bad things can happen. I found that the voltage sensor can be a little off if you pair the packs ie you can't blindly tust it. If 1 pack fails in flight you got big problems and it can cause you to crash (or if it's uneven). I found just buying a bigger pack seems to have better results as 2 equals a few G more over 1 larger capacity. Right now I like the Lion power 25C 4s 10400 lipo it's about 1000g and 2 6000 packs is 1200g they get the same amount of flight time but the cost for 2 6000 is more then 1 10400 pack so price it out. If you want more reliable use 1 pack it starts to fail at least you can see it doing funky things with 2 packs you won't notice it droping as the other pack will make it appear to be fine.

 

[tombrown1]

I'm a believer in 2 packs and lipo alarms. I had a lipo go bad in midair, alarm went off, and the other lipo kept it afloat until I could get her down. If it was 1 lipo that went I would've gone down hard.