H920 replacement battery

[Dougcjohn]

Limitation is the battery bay, the H920 itself has a pretty hefty payload limit beyond the CGO4. If could carry additional batteries, up the point of weight vs energy ratio become zero. As you add batteries, you won't receive the same "per cell time" due to adding weight the payload, but you should gain minutes.

Yep, make a 3D Plate that fits the curvature of the top housing placing 2 cells on each side of the lids curvature or 1 down the center. As an experiment, HD velcro tape could be use to experiment the extended Time of mAh to weight.

So is the goal to have these mounted outside the battery bay to use the 3rd battery port? If so is this option good because of balance and a reduction in weight? That's the best I can do to wrap my little grey matter around this!

Another benny forgot to mention, the 3S are normally lower cost where 2 is still lower cost than 1 6S.

Various testing of different saddle batteries from 6S and 3S, the worst has added only a few minutes (Useless cost), the best so far has added about 50-55% of the standard main battery's time. These 3S LiHV will be a new test that I'm hopeful will perform.

 

[Dougcjohn]

Limitation is the battery bay, the H920 itself has a pretty hefty payload limit beyond the CGO4. It could carry additional batteries, up the point of weight vs energy ratio become zero. As you add batteries, you won't receive the same "per cell time" due to adding weight the payload, but you should gain minutes.

Yep, make a 3D Plate that fits the curvature of the top housing placing 2 cells on each side of the lids curvature or 1 down the center. As an experiment, HD velcro tape could be use to experiment the extended Time of mAh to weight.

 

[PatR]

Keep up the good work! Flying two sets of stock batteries today in no wind conditions the best I could get out of them was about 12 minutes of constant slow maneuvering and recording before getting hounded by the first battery warning. Worse, just after that the system would not permit any more video recording. The Zippy’s did much, much better. The possibility of an additional 5-8 minutes of “Zippy time” before the first warning would be outstanding.

The reason I’m so obsessed with the first battery warning is because it’s extremely annoying due to multiple pop up windows and causes a lot of distractions clearing the repeated pop ups. Much to interruptive of what you are working on.

 

[thoneter]

Another benny forgot to mention, the 3S are normally lower cost where 2 is still lower cost than 1 6S.

Various testing of different saddle batteries from 6S and 3S, the worst has added only a few minutes (Useless cost), the best so far has added about 50-55% of the standard main battery's time. These 3S LiHV will be a new test that I'm hopeful will perform.

Are the 2s's that you have displayed less than the 1 zippy?

 

[OnTheRopes]

Keep up the good work! Flying two sets of stock batteries today in no wind conditions the best I could get out of them was about 12 minutes of constant slow maneuvering and recording before getting hounded by the first battery warning. Worse, just after that the system would not permit any more video recording. The Zippy’s did much, much better. The possibility of an additional 5-8 minutes of “Zippy time” before the first warning would be outstanding.

The reason I’m so obsessed with the first battery warning is because it’s extremely annoying due to multiple pop up windows and causes a lot of distractions clearing the repeated pop ups. Much to interruptive of what you are working on.

Had this problem yesterday, filming using CCC. First warning went off but plenty of life left in the 3 Tattu's. I couldn't figure why it wouldn't fly the CCC and wasted loads of time messing about, this happened with 2 sets of batteries until I remembered it stops all programmed routes on first battery warning.. I didn't notice whether I could film at this point as I was so frustrated with not being able to fly my plan.

 

[Dougcjohn]

Are the 2s's that you have displayed less than the 1 zippy?

The LiHV example I have shown are 3S 5200mAh, you wire 2x 3S together to have a 6S 5200mAh. The purpose, 3S batteries (LiPo for 920) are normally a tad less than 1/2 the 6S physical size. Place a 3S on each side of the curved top for balance in a Series Lead, and plug that into the open 3rd port on 920 for 1 more 6S 5200mAh battery.

Their weight... in this example of LiHV are a little lighter: 2x 3S 5200mAh compared to 1x 6S 5000mAh. Now, it's not apples to apples, one is a LiHV 10/25C and the Zippy is 25/50C... the higher C rate will normally weigh more. Main focus is splitting the weight on topside for balance.

I also looked at the 920 a bit more... instead of defacing the battery door.
Leave a connector off the External End of Extension lead. Drill a small hole (for middle port) on the underside just in front of the battery door inside the battery chamber big enough for the wires & a grommet. Pass wires down through exit hole, solder new lead (EC3, XT60, XT90, etc) on extension. Make extension long enough to tuck in back of Gimbal frame when not being used, or pull up into battery chamber for storage. Make 2-1 Serial Extension lead for batteries. This provides a cleaner install that remains clean when not using or if desired to sell the 920 and new owner didn't want a hole in battery door. You could pull the battery lead and replace grommet with a plug of same size.

 

[Dougcjohn]

Examples of H92 Extension Batteries for Top side mount:
Match Internal with 5000mah: for a 15000mAh total.
LiPo 3S 25C 5000mah @ 361g 2x 3S 722g (55g heavier than 1x 6S) @ $33.40 each
ZIPPY Compact 5000mAh 3S 25C Lipo Pack

High Capacity 8400mah for a total of 18400mAh.
Each cell @ 615g 2x 1230@ $110 each (expensive)
Turnigy nano-tech 8400mAh 3S 30C LiPo Pack w/Flat Connector

High Capacity 6200mah for a total of 16200mAh.
Each cell @ 451g, 2x 902g at $51.00 each
ZIPPY Compact 6200mAh 3s 40c Lipo Pack

*** Weights are listed differently between Spec section & Listing section
*** I used the Spec Section, actual was different than both weight but closer to Spec section.

Personally, the 5000mah @ $33 each, $66 total is a nice cost for Energy Increase and basically a matched pair for Internal 5000mah 25C. Physical size is nice too: 155x25x44mm

 

[Dougcjohn]

EC3 Extension Lead... cut off one end to pass through grommet / plug.
https://www.amazon.com/3drcparts-SI...1523794159&sr=8-3&keywords=EC3+extension+lead

Dual Lock Hi Tension
https://www.amazon.com/dp/B007OXK330/ref=sspa_dk_detail_0?psc=1

Wire Grommet or Plug to have tighter seal of wire.
Plug example, I would go with 1/4 to 3/8"
https://www.amazon.com/Piece-Flush-...rd_wg=JDrmd&psc=1&refRID=7VNQFCCZMHG70MJ9TT69

Grommet example:
https://www.amazon.com/OCR-Grommet-...d=1523794011&sr=8-5&keywords=electric+grommet

A trip to the Hardware store for a single or small bag would probably be cheaper.

 

[PatR]

Good ideas Chris. Someone with a 3D printer would prolly have no problems designing a frame mount that attached to the bottom of the gimbal mount standoff’s to wrap upwards over the body. It might be an idea to design it in a manner that kept the aux battery well clear of the GPS tower.

 

[Dougcjohn]

Playing with ideal location options.
I was going to test the "flight time hover" comparison using velcro for now to see if it's a strong benefit.

Thought of both upper & lower mount up. I'm leaning more towards the topside to keep it out of the way of the gimbal movement. Need to play a bit to fully determine. Considered the GPS tower, kinda dismissed it due to it's height and the cells being 25mm height and not directly near GPS mast, I'm visualizing more above and to the sides of the battery chamber.

Maybe even better location: another location that might be nice. The top or bottom of the 3&5 and 7&9 motor arms, up against the main fuselage. If the batteries cleared the retracting strut gear, under the motor arms would be best.

I'll order a pair of the 3S 5000mah 25C to get some hover tests.
Engineering & Logically, this should be an improvement and not a technical electrical challenge with the 3rd open EC3 port. I place the zippy's on L & R side leaving center space. That would be a good storage of extension wire when not used too.

An advantage of the motor arm mounts... would be more of a plate to distribute load evenly and not so much to obtain the curvature of the fuselage. I'm visualizing a upside down Korean War Era Bell 47 Skid gurney upside down under the arms.

 

[PatR]

Tend to agree with the boom mount concept. Remaining clear of gear swing is the only limiting factor. OTOH, using a single battery instead of a pair simplifies things in some ways. The additional weight is pretty much negligible for the aircraft’s capabilities, even considering the offsets of added weight over flight time. Then again, it might be an idea to ballast the aircraft to match the weight of extra batteries to determine how much that reduces flight time in order to establish the true gain in flight time after adding batteries.

There’s a lot of variables to contemplate with the mA, flight time, weight equation considering the use of 2 larger capacity Zippy’s provide more flight time with less total mA available than 3 stock batteries but at less weight. As the original 920 was intended to make use of different cameras there may be quite a bit of latitude to play with.

 

[Dougcjohn]

Totally agree on the larger capacity, using 2 batteries I feel is needed for balance. Using 1 would need to be placed center or ballast and if ballast, prefer it to be energy. Thought I'd try the 2 smaller 3S first, then use the same mount point and attach 2 extra zippy 6S 5000mah as a heavier energy payload. That would be a total of 20K with 4x 6S 5000mah batteries.

Hmmmm.... while I'm waiting for 3S 5k mah, might just try the 4x 6S 5K mah.
But with a fresh 3" snow & winds, I'll wait for the Spring temps if it'll ever get here.

Speaking of which, feel for Thoneter, he received about 2 Feet and 80mph winds.
Yep, this is Iowa!!!

 

[thoneter]

Thoneter just spent 4 hours cleaning 3 driveways and the neighbors home also. Thoneter is to old for this crap

 

[PatR]

The last winter I spent in the Pacific Northwest was the last of its kind I ever wanted to deal with. Not as bad as yours but bad enough for me. Back when I was snow boarding I loved snow but I had to travel some to get to it. The “home delivery” version falls well outside of my list of preferred residential location attributes.

 

[thoneter]

Yeah at almost 60 I'm not as big of a fan of the "home delivery" either. Especially when the snowplow guys get enjoyment in figuring out how to pile up the most snow in the place where you least want it. Reminds me of the Chevy Chase movie where they moved to a place in snow country. It's cool for the first 5 times but begins to wear on the soul after 25. At least the plowers get some satisfaction out of it.

 

[PatR]

The city clearing crews seem to prefer piling and packing snow in front of driveways and over mail boxes. Neither of which they have any responsibility to clear. If allowed to sit for very long you need a jack hammer to break it up.

 

[thoneter]

I don't know how they did it. The snow plow piles along the whole block were 3 feet tall and 5 feet tall directly in front of my van. I had snow covering the whole hood from the plows even going up the windshield to the top.

 

[Dougcjohn]

Indirectly related, finishing up on testing saddle batteries on the Inspire 1.

This should be even more benificial for the H920 that has a higher payload specification and heavier OEM Battery 3-pak that isn’t utilized much due to battery options.
If balancing payload, may want to use 2 Serial or 2 parallel, depending on Ah desired & weight. OEM 490g x 3 1470g,
Zippy 667 x 2 1334g, 4 Zippy 2668g plus saddle mount.

I essentially doubled mAh payload: OEM battery 5400mAh and 5200mAh saddle. I made a 2S to 1P XT60 connector and used 2 x 3S 5200mAH in 4 test sets at 50F, gusts 12-16mph: 1 Test = 1 standard battery setup & saddle pak setup, flew at 50’ in hover till 1st low battery warning and 2nd battery warning. Had expected estimated gains of 25-30% (3.5-4.5 minutes) due to weight increase offsetting energy increase. I was surprised to see about a 40-43% increased in flight time (6-7minutes) for a 21~22 minute total, up from 15 minutes. All tests ended with battery bank indicating 15-17%, LiHV cell 3.47~3.48v, 20.7volt reading on console during touchdown landing. Note: LiHV starts at 4.35 with same bottom end 3.2 volt spec as LiPo.

Based on the payload the 920 can easily manage, Doubling mAh 10400mAh to 20800mAh as test base shouldn't be as challenging to H920 as the Inspire 1 to lift the additional payload. Using 2 x 5200mah Zippy in bay and 2 x 5200mah on saddle mount, I’m estimating a 55-60% increase.

Over / Under reaching estimates? Hmmm...

 

[OnTheRopes]

Indirectly related, finishing up on testing saddle batteries on the Inspire 1.

This should be even more benificial for the H920 that has a higher payload specification and heavier OEM Battery 3-pak that isn’t utilized much due to battery options.
If balancing payload, may want to use 2 Serial or 2 parallel, depending on Ah desired & weight. OEM 490g x 3 1470g,
Zippy 667 x 2 1334g, 4 Zippy 2668g plus saddle mount.

I essentially doubled mAh payload: OEM battery 5400mAh and 5200mAh saddle. I made a 2S to 1P XT60 connector and used 2 x 3S 5200mAH in 4 test sets at 50F, gusts 12-16mph: 1 Test = 1 standard battery setup & saddle pak setup, flew at 50’ in hover till 1st low battery warning and 2nd battery warning. Had expected estimated gains of 25-30% (3.5-4.5 minutes) due to weight increase offsetting energy increase. I was surprised to see about a 40-43% increased in flight time (6-7minutes) for a 21~22 minute total, up from 15 minutes. All tests ended with battery bank indicating 15-17%, LiHV cell 3.47~3.48v, 20.7volt reading on console during touchdown landing. Note: LiHV starts at 4.35 with same bottom end 3.2 volt spec as LiPo.

Based on the payload the 920 can easily manage, Doubling mAh 10400mAh to 20800mAh as test base shouldn't be as challenging to H920 as the Inspire 1 to lift the additional payload. Using 2 x 5200mah Zippy in bay and 2 x 5200mah on saddle mount, I’m estimating a 55-60% increase.

Over / Under reaching estimates? Hmmm...

Interesting, do you have a saddle mount yet for the 920? I would love to see some photo's.
On a side note Yuneec UK have had some 5000mAh batteries made for the 920 (2 batteries fit and 30C).
The trouble is these are £130 each so that's a bit of a no go

 

[Dougcjohn]

Have for Inspire, not H920 yet, I’ll rig up a not pretty solution first to run tests to see if overal worth the effort on the saddle.
Pat & I were discussing location, thinking on motor arms near fuselage. Need to play with topside or underside. A single would be topside center most likely.

I know you & Pat have been on the subject, are the Zippy’s available... low cost, good performer.