Battery Trouble

[Justin]

So I just purchased two 3S 2200mAh 30C Turnigy batteries for my new Knuckle H Quad. I originally calculated which battery I needed on a motor that pulled 15 amps, so 60 amps in all. 2.2 times 30 equals 66. I was set. But then I got interested in some different motors and purchased those instead. Each one pulls 17 amps at its peak, so 68 amps in all. I forgot to redo my math for the new motors. Motors pull 68, batteries supply 66. However, when the motors are at 17 each (68) they are at full power which means the 30C battery would burst at 40C for ten seconds. Please correct me if I'm wrong, I'm new to multirotors. The order is already placed and should be arriving any day now (elapsed time 16d 22h). Based on my own calculations I should be fine, but I do not know if I am correct. Am I okay with the batteries I got?
P.S. I ordered a parallel adapter so If that can help It would be great!
P.S.S. I ordered 30 amp ESCs for expanding purposes (i.e. FPV, drops, etc.). My ESCs are fine.

Second Question. I now own three Lipo Batteries (when order comes in it will be five). One has been in service for four years and is puffed (3S 1300mAh 15C for my Super Cub). I ordered another battery for the Super cub a few months ago (same type[a little bit puffed]). A couple months ago I received a Parkzone T-28 and with it came a 3S 1800mAh 15C) it is in perfect condition. Anyways I thought it was about time I store them safely. I found a thick brass bowlish thing (more like a cylinder). I thought I could store my Lipos in there and cap it off with cardboard wrapped in a lot of aluminum foil. I don't know whether to store it in the basement on a concrete floor or in my room, where they can be easily checked on every day. I will try to upload a picture of my situation ASAP.
P.S. I ordered an Accucel 6, so I will be able to storage charge my batteries. I also ordered a large Lipo safe bag from Horizon Hobby which mysteriously hasn't arrived in the two separate packages I received from them.
P.S.S. Are Lipo safe bags fire resistant? Can they sustain a Lipo Fire?

THIS IS IMPORTANT

 

[lonewolf7717]

if hooked up parallel your total capacity will be 4400mah @ 30c....or 4.4x30= 132 amps.....you good man. so far as lipos, i like to keep my close and at hand. will also have better control of temps in your room vs basement. lipos don't do well with wildly fluctuating room temps.

 

[Justin]

Thanks lonewolf7717 for your quick response! I will try to get pictures uploaded by the next day. And do I have to fly with the batteries in parallel?

 

[lonewolf7717]

extra note: if its your first experience with paralleling lipos one hint. make sure the lipos your pairing up are both roughly the same age and general "health" not to mention close in voltage. the voltage thing does not have to be exact but dont go throwing two batteries together that have massively different voltages. health is important because if you have a "saggy" lipo paired with a fresh new one, the useful life of the fresh lipo will be reduced. electricity just like water prefers path of least resistance which will put a high demand on healthier lipo.

 

[lonewolf7717]

advised to run parallel, keep in mind though if you are pulling north of 60amps at WOT you may want to take a close look at type of connectors you are using and make sure they are rated for more than 60.

 

[Tritium]

LiPo's generally have burning issues only during Charge or Discharge. I have not heard of any issue with a stored LiPo causing any fires but if someone has please post a link.

Thurmond

 

[Justin]

Fortunately I am aware of how to properly parallel. I watched the FliteTest video. But can I fly on one battery? Thanks

 

[Justin]

Oh sorry, didn't see your third post, lonewolf. I am using XT60, 3.5 mm bullets for the ESC to battery, and 3.5 mm bullet for the ESC to motor.

 

[Tritium]

Full throttle is rarely used for any length of time except on Acro flight so standard flight will most likely never harm the 2200mAh 30C battery.

Thurmond

 

[Craftydan]

How many posts around here aren't important?

Multirotors are *rarely* at WOT (wide open throttle). I think you'll find the extra thrust from that last 1A/motor will be negligible.

Now is that 17A measured or rated? your selected props may never demand that current on 3S.

Storage? Cool, dry and neutral voltage -- keep it out of extreme heat, don't let it get flooded, and somewhere between ~30-60% capacity. and keep the contacts from shorting, but that should be obvious

The Lipo bags are useful for containing fires started while charging -- doesn't hurt to store them in one, but once a pack has cooled after a flight or charge cycle, almost all of the risk is diminished.

 

[Justin]

I just checked and XT60s can handle 60+ amps for an extended period of time. I'll just put it in one of my prop washes.

 

[lonewolf7717]

as others have said though, that craft may very well never even see 60amps....i mean unless you are doing a beer lift or something.

 

[Justin]

I'm using XT60s. They are rated for 60 plus amps for and extended period of time. 60 amp constantly. Would it be smart to position the connector under a prop wash? Whoops, I thought I deleted my previous post.

 

[Justin]

Do the batteries always supply its full capacity or does the ESC pull what it wants?

 

[Tritium]

ESC pulls what it needs. Battery current trickle, craft at rest and battery current gush at WOT.

Thurmond

 

[Justin]

CraftyDan, the 17 amps is what was posted on the specs. so I guess that is rated. But for 8x4.5 props it is 9 amps.

 

[xuzme720]

I'm using XT60s. They are rated for 60 plus amps for and extended period of time. 60 amp constantly. Would it be smart to position the connector under a prop wash? Whoops, I thought I deleted my previous post.

I don't think you'll need it. I would recommend looking into getting a wattmeter so you can verify your actual amp draw. It's a good diagnostic tool and can also be a safeguard against burning up gear by catching any overcurrent power systems.

 

[Justin]

I'll look into that. And what is "it" referring to?

 

[xuzme720]

Do the batteries always supply its full capacity or does the ESC pull what it wants?

It's the load on the motor that determines how much amperage you are pulling through the ESC. The ESC and battery will only try to supply what the motor draws so that is why prop selection is so important and why it's bad to overprop too far.

 

[xuzme720]

I'll look into that. And what is "it" referring to?

"It" was referring to putting the connector into the propwash. I don't think you'll need to do that. I doubt you'll be pulling full amperage unless the multi is really heavy or overpropped