In continuation of selecting the best motor for my X8 (Octo coaxial) build for video/photography (see post here : http://www.diydrones.com/group/arducopterusergroup/forum/topics/tig...),
I must now compare and select the best battery in 6S votlage. I collected some information on various web site to compile a comparison for three categories of 6S batteries based on capacity : 5000 mah, 6000 mah and 8000 mah. I intend to fly with two packs in parallel, so I did not care to analyze bigger capacities like 10.000 mah , also because they are hard to find in these common brands : Zippy, turnigy nanotech and Kypom (i limited the comparison to these three brands because they can be found quite easily online in Europe and in the US, thanks to the Hobbyking web site, the onlylipo.com web site and the altigator.com web site, etc).
I defined five criteria as follows:
-price (in euro)
-weight (in grams)
-power density 1 (capacity in mah divided by total weight of battery). Higher is better. You get more capacity per gram.
-power density 2 (capacity in mah divided by total price in euro). Higher is better. You get more capacity per euro.
-Compacity. This is the biggest dimension of the battery in mm. Smaller is better. I chose only to compare on the biggest dimension because this is the constraint of my craft (battery holders are max 170 mm long in my design)
And the winners are :
-In the 5000 mah category : Zippy 30 C. It is best on 3/5 of the criteria and second best on 2/5 of the others in an unsignificant manner.
-In the 6000 mah category : Zippy 30C (again). It is best on 4/5 ot the criteria and second best on 1/5 of the others in an unsignificant manner.
-In the 8000 mah category : guess what... Zippy 30C (again again). It is best on 3/5 of the criteria and second best on 2/5 of the others.
Unless Zippy batteries are bad quality, Zippy seems to be a great battery. I would like people who have experienced Zippy batteries to give here in this post their testimonials about their quality and durability ?
You read the Instructions??? You must have been desperate...:-D
Re: the maxamp 11000 3S 40C.
With the XT60, mine comes in at 660g exactly, so significantly more than the advertised 620g.
mind reader! you are full of surprises.
So advertised was 908 and actual was 882. That's a good start.
for how long have they been offering 33% off?
I'm getting suspicious. My e-mail came back. Invalid address. any chance they are going out of business or am i adding 2 + 2 and getting an irrational number?
maybe i should call
On your next use (if you still use it), can you track % charge before the charge (after your flight), the charge amount, and then the immediate post charge %. That will tell us a lot about what we need to know.
Naw - still very much in business. I've been talking to Clint just the last few days about becoming a reseller (since my new design is geared to take their larger sizes, and their performance is good).
Maxamp are expensive, but their service is worth paying for, IMO.
I am genuinely interested to see how your testing turns out, especially if you decide to venture into 3S. I'm planning on a 2nd design "Mini-Platypus", 450 size, geared around gopro style cameras and generic gimbals, and crucially - 30 mins+ flight time on 3 or 4S. And interestingly, 20+ flight time at 3,000m. Don't ask me why...;-)
I see maxamps do a "high C" version of the 10900 in 3S now as well, so I might explorer this once I see your results :-)
If you do venture into the land of big amp 3S, I'm happy to lend you my "run in" maxamp 3S 11000. Postage back to Switerland will be a bitch though...
Yep - will do. Once it stops raining :-(
Will do the full outdoor hover test, so you'll get flight time as well. I'll run it right to the 3.5V alarm (@ idle). That'll be a more accurate "full use" scenario.
so encouraging. can you get me a contact (phone and e-mail)? are they still out of Spokane, Washington or did I get that wrong?
clint 'at' maxamps.com (509-473-9883). Still Spokane, to best of my knowledge.
Ok, did my "Terence" maiden, and the the battery stats are below. Had to cut short, due to my compass mast falling off, so had to land.
Pack: 10900 6S Maxamps
Start volts: 4.2/cell, charged 2 hours earlier
End volts: 3.84/cell idle
mAmps put back in via 1C balance charge: 4800 to 4.2V for all 6 cells. 5050 to "Full". This pack does seem to take forever to get to "Full" and fully balanced.
That's a valid point.. that the test Watt load should vary depending on the battery weight, since it will incur different hover loads.
I've been using 150W because that's the highest my CBA can go, even with external cooling, and all my configurations hover over 150W anyway.
I'd like to make a similar graph, with Hover Amps on the Y axis and Battery Weight (gr) on the X axis.
(Then another with WattHours Capacity on the X axis.) mAh doesn't tell a whole lot, since it doesn't take into account the voltage under load, as you noted.