H920 replacement battery

[PatR]

The battery port is only about 46mm or so tall and a little over 90mm wide so any pair that exceeds about 95mm or so in width won’t make it even when outer wrappers are removed. 120mm is way too wide. You’re welcome to give a run at it to try though[emoji6]

 

[Dougcjohn]

Well, that’s my error & misunderstanding. I questioned the bay width based on what I thought was indicated as OEM battery width of apx 38~40mm. I received my 920, so just unpacked and see OEM batteries are 30mm. Yep, that changes the plans! LOL! BTW, Nicely packed setup!

 

[PatR]

It is packed quite nicely. Congratulations on your acquisition! If you don't mind my asking, who was the dealer or was it a private transfer?

Back to the Zippy 5000mA batteries.

Just received both of those ordered. Shipping and delivery were very fast this time. First look suggests these will be a slam dunk for a dual battery fit as both slide in with room to spare. There's enough open space remaining at the battery door that power adapter wires will not pose many issues with closing the battery door. This ends up pretty important because the 920 has a battery door open warning they never told anyone about. if the door is left all the way open and down the status light starts blinking orange or red and the ST-16 displays both GPS and Compass warnings. I checked this with Seabee and his does the same when the system is powered on and the battery door left fully open.

There are minor differences in size and weight.

Zippy-1
Weight: 670.4g
Physical dimensions: 155mm x 44.98mm x 46.75mm
Voltage as delivered: 22.59v

Zippy-2
Weight: 672.7g
Physical dimensions: 155mm x 44.48mm x 46.64mm
Voltage as delivered: 22.61v

All that's left is finishing up a pair of adapter leads and a test flight or three.

View attachment 8402

 

[Dougcjohn]

Private Sales distributor... my guess is they acquire inventory of other shops closing, bankruptcy, etc., Outer boxes of H920 & CGO4 indicated US models, the V18 had a EU number. New H920, not upgraded (been looking for non-upgraded), 2 - ST24 Controllers, V18 Zoom Camera and CGO4 full setup. The 3 cases: H920, CGO4 package, and the V18 camera & gimbal. The quality of cases and the orderly packing & cutouts does present a nice statement.

 

[PatR]

Sounds very nice. A very large distributer filed a 13 late last year. Set Yuneec back about $10.3 mil.

 

[Dougcjohn]

I'd assume Bankruptcy assets are where they're getting all the new product... outer boxes had that look of not being handled much, like warehouse shelves. All the boxes were shipped heavily wrapped in clear plastic wrap. When I first encountered, they had several items of primarily Yuneec items; as my decision pondered they pretty much emptied their inventory, I grabbed the last H920 and pondered too long & missed a GB603 setup.

 

[PatR]

In case you're not aware, some in the UK and EU are fitting Gremsy gimbals, a secondary remote, FPV cam, and a 1080 video transmission system to 920's. A Gremsy will handle a wide array of cameras and lenses. That's for a bit down the road though. Then again, I don't think any of that is new to you as you come across as knowing what you want or need to do already

 

[Dougcjohn]

Yes, I read a few of those threads on applying the Gremsy. I considered that gimbal as a possible method to mount a Flir; that will wait for a need, first need to explore the ET.

I’d rather utilize the “negative impact” of the h920 platform and cost of components. Still all great hardware and platform within their design limits, but abandonment of the platform is beginning to present opportunities to those using the 920’s in comparison to cost of compatible.... newer platforms. It misses the boat on a few things, overall it’s a great bird.

Still amazes me how quickly it fell from the top ranks. Reading articles even in 2016 had strong positive ratings for the 920 (old gen), and a shorter lime light, still strong for the 920+. This is on a platform basically less than 2.5 yrs old. It clearly shows the hardware component was superior, but software development to expand and refine never took off. I thought there would be aftermarket 3rd party by now making mods, !!Batteries!!, or total circuit revamps. Why reduce a controller with 24 channels to a 16; initially I feel there were plans to add and develope the platform utilizing more features and channels. A small... maybe hopeful thought, as the 920 drops, it may become an doner to a new development by 3rd party.

 

[Dougcjohn]

Back on batteries, I’ve searched a lot to find a USA source for the Tattu 4000mA 15C 6S. Also checked a few LiPo custom shops... unable to find a pak that’s under 30mm. Why is Yuneec & Tattu the only source under 30mm for 4K 6S.

Did you ever determine why that specific Tattu model is not sold in USA? I communicated with 2 USA sites dealing in Tattu, neither was willing to add that model to their inventory.

Communicating with a Belgian shop if they’d ship Tattu to USA. Most European shops are not willing due to all the additional requirements for LiPo.

 

[PatR]

I've not received a clear answer and I've communicated with a rep in China a few times about the U.S. battery thing. There is some interest in making a new battery for the 920 but I haven't gotten back to them with development data yet.

As to why Tattu never made the 920 battery available in America, I have a theory. It was about 3 years ago the Tornado was first being advertised. About the same time our FAA was sending letters to power distribution, energy development, and real estate companies forbidding the use of commercial sUAS and threatening them with terrible penalties if they persisted. That at that time the FAA did not yet have laws in place that would permit that to happen it didn't matter because all those receiving the letters figured if the feds were sending letters they must have the power so they cancelled all the contracts they had with commercial sUAS businesses. There was suddenly no market for commercial level sAUS unless you happened to be one of the 6 original Part 333 holders, and those were for the most part flying custom rigs for cinema work. Yuneec didn't have a market here for the Tornado anymore and likely sold very, very few, leaving no reason for Tattu to import batteries for them.

Europe and the U.K. were not experiencing that level of regulatory control yet and their sAUS operators were going strong in their activities. Things were so good that people here in the U.S. were taking cinema contracts overseas. So the Tornado, which was easily the one to beat where quality and capability were concerned, had a ready market and sales went pretty well there despite a price tag of >7000 Pounds. People already doing aerial work were well aware it would cost them well over 10,000 Pounds to build their own heavy lift camera rig. The gimbals alone could cost that much. I know this because I built some at the time and all the great frames came from Europe and the U.K. The relatively low price of the Tornado made it possible for those wanting to get started on low budgets to do so as well. The number of 920's sold in the EU and UK was enough for Tattu to make and import batteries for it over there. Two years later the IATA became very concerned (rightly so) about transporting lipo's in passenger aircraft. There had already been the loss of a UPS 747 freighter and crew, with the cause suspected of being an uncontrollable lipo fire in the cargo hold. Following that there were one or more lipo fires erupting in cargo storage and aircraft cargo bays at Asian airports. So the bulk shipment of lipos on passenger aircraft was terminated and tighter regulations for bulk shipment of lipos for air freight carriers got a lot tighter, driving up the cost of shipping them. Hence the deliberate mislabeling of batteries by a couple of Chinese companies to present them as lower in W/H. Combine a low number of 920 units sold in the U.S. with increased shipping costs and regulations and I can understand why Tattu ignored us. The push for new batteries didn't come about until Yuneec, in their infinite capacity to make strategic mistakes, elected to convert the 920 fleet to the 920+ roughly a year ago. That just happened to coincide with some rather negative Asian press releases concerning Yunnec's financial state. So combine a battery production run that was nearing the end of battery calendar life with a converted 920 system that placed a higher current demand on the battery along with possible financial distress and we suddenly had a high demand for better batteries that just weren't there. Lacking unit sales numbers to provide a business reason to support importing them they have no reason to expend the effort, especially as they would be importing to a warehouse in a state that is very unfriendly to business and has a significant inventory tax assessed on product left sitting on a shelf.

For the moment I'm happy there are alternative batteries that will keep us safely in the air with decent flight time, at a cost significantly lower that what Yuneec is trying to unload on us. As Yuneec can't make a good business decision to save their a$$ (Yuneec's CEO needs to read Sun Tzu) I don't believe there's any chance of them resurrecting or providing any additional improvements for the 920, which would include contracting for a better battery. So we have a very capable camera rig that performs quite well, is now extremely reasonable in price, that just needs a continuously available power supply to keep it going. It's certainly not worn out or obsolete, still shoots great video, and the airframe provides a lot of opportunities for payload, flight control, and heavy lift customization. None of which are possible on any DJI product less than a Matrice. It makes no sense to run out and buy a new camera rig every 6 to 8 months when the new improvements are relatively small. From a business standpoint it makes far more sense to buy a rig that allows for future adaptation for incorporating different payloads. All they have to do is reliably carry a camera or sensor. If we know how to fly them everything else is fluff. A single rig design can and should be able to carry many different payloads.

BTW, if anyone wants to dive in and help in alternative battery research I won't mind. I really can't afford to be buying a bunch of different batteries to test them all out. Seabee has a couple of possible selections but he's frozen in, and I'm certain there are many more beyond those.

 

[Dougcjohn]

A very large distributer filed a 13 late last year. Set Yuneec back about $10.3 mil.

A few Google searches... last year wasn’t a good year for many Hobby, Sporting Goods, Toy and Distribution companies. Several big outfits fell, I had heard of several, and several didn’t even know existed.

The Hobbico Filing this month is another big one. May have several RC brands showing up in clearing enterprises.
Although I’ve noticed recently in the last year, the true hobby stores in my area have stopped carring DJI & Yuneec... in discussion they blame BestBuy & BigBox type stores.

 

[PatR]

The big box store situation will be getting worse as Best Buy is either now or soon to become a certified Yuneec repair station. That undercuts the established dealer repair station network. Hobbico was certainly a big one but long in coming. They had been screwing over their hired help and business accounts for the last couple years. The Hobbico situation has me wondering how well Horizon is holding up. I haven't followed either Hobbico or Horizon much since I stopped flying G.S. 3D 5 years ago. Know anyone looking for some real big aerobatic airplanes?

Chinese hobby manufacturers have a looong history of hammering their dealer network by opening up new dealers whenever they aren't getting the anticipated sales volume from existing dealers. They'll open up a new dealer right next door if that;s what they feel is needed. Used to be you had to buy "X" amount of product every month whether you sold it all or not. If you missed an order you got a stern warning. The next miss or reduction in order quantity would see new dealers pop up in your area. DJI did similar after a U.S. court blocked imports sometime around 2013, or about the time the A2 FC was released. They could not import into the U.S. so they imported to new Canadian dealers who then shipped to the U.S. or partnered with a couple of select U.S. dealers. Most of the U.S. dealers couldn't buy anything wholesale and lost their customer base.

 

[Dougcjohn]

You are correct, if you can obtain the Tattu batteries inside the U.S. You have my interest piqued with the Turnigy revelation, especially as the stock Yuneec battery dimensions at 170x45x39mm. If three Turnigy's won't fit the next closest alternative is a pair of 5000mA Zippy batteries

My miscalculations on OEM battery width stemmed from the 39mm width... knowing it exceeded the indicated 95mm chamber, I made wrong assumption. Thus 39 ‘‘tis a 29... sorry to have generated several posts on non-compatible Tri-pak battery options and wasted reading. Onward...

 

[PatR]

No problem and I had already given up on the tri pack concept. Back to the Zippy Compact 5000mA batteries.

Very Important; if someone takes this path they need to pay close attention to the length of the power adapter length. Anything longer than 4" causes wire and connector bulk to interfere with closing the battery bay door. You MUST be able to close the battery door and allow the magnetic catches to connect. If they do not the system will generate compass and GPS warnings.

The first ones I made were both 4.5" and 5" long and I had to force fit the wires into the bay to allow the door to close. Not an ideal situation. I shortened one of them to 4", which allowed easier wire routing to allow the door to close. An adapter length of 3.5" to 4.0" works out well. Make them both the same length. Also perhaps helpful is to obtain XT90 connectors for your charging cables and adapter leads with anti spark technology. There is potential for an electrical arc when completing the electrical circuit even when assuring the ground makes pin contact before the positive pin if the connectors lack an anti spark capacitor. They cost more but your connectors will last a lot longer.

Batteries are charging now and I hope to obtain the IR's for both and get in a test flight before an approaching storm arrives.

 

[Dougcjohn]

Looking at your pics of the Zippy 5K pair appears you do have clearance, do you think you've got 7mm additional clearance? The Zippy Compact 5.8K is same width but tad taller at 53 vs 46mm. Not a major improvement, but provides 1.6K bump.
ZIPPY Compact 5800mAh 6S 25C Lipo Pack With XT90 at $71, about a $12 bump per battery to the Zippy 5K.

 

[Dougcjohn]

On the 920 vs 920+, flight time dropped. What's on the 920+ that pulls additional power? From all the various threads, I assume it was significant to effect flight time so much.

 

[PatR]

I don’t know for certain. I’m assuming when they changed the flight control board they also changed the power distribution board and incorporated ESC’s having a different rating. ESC’s are most efficient when run at or close to 100% capacity. When run at lower output they waste energy via resistance heat.

 

[PatR]

Tornado 920 Plus
Zippy Dual 5000mA Flight Test

Having charged the Zippy 5000mA batteries to full capacity at a 1C charge rate it was time to put them to use for flight testing. The following are conditions and observations made before, during, and after the flight. For those lacking patience the end result was a flight flown normally, camera recording 4k from the time of takeoff, gear cycled multiple times, with climbs and descents, for a total time of 0:25:39, or 38 seconds more than the best I have obtained using three new Yuneec batteries. Considering I paid ~$118.00 for a pair of Zippy batteries and obtained slightly better flight time than when using three new Yuneec batteries, and that Yuneec’s price for a package pair works out to $139.995 each, for a total cost for three batteries equaling $419.985, my use of Yuneec batteries for the 920 has reached an early end. I can buy three sets of Zippy batteries for $66.00 less than a set of three Yuneec batteries. Topping that is a pair of Zippy batteries weighs less than three Yuneec batteries which means the system does not have to work as hard.

The 2000mA of additional capacity using the Zippy 5000’s over the Turnigy 8000mA Graphene battery provided ~4 additional minutes of flight time in conditions roughly 10 degrees colder than when the graphene test was performed. The wind conditions for the Zippy test were easily double those for the graphene test. We might interpolate that each 1000mA of additional capacity could add 2 minutes of flight time when using batteries of higher quality that what Yuneec provides. What is certain is that a pair of Zippy 5000mA batteries provide flight time at least equal to what three Yuneec batteries provides for the 920 Plus. We have alternative battery choices available to us, we just need to research and take advantage of them.

For those that like statistics, the following;

Conditions:

• Baro: 29.88inHg
• OAT: 54.6*F
• Wind: 3-7MPH
• Density Altitude: negative 105’ MSL
• Humidity- 55.8%
• Dew Point: 33.4*F
• Sky: Overcast, incoming storm front
• Altitude of flight: varied, 78’ to 392’AGL

Battery State:

Zippy #1 charged to 25.2v as indicated by Hitec X2/400 dual DC Charger. Independent volt meter check indicated 25.22v

• Cell Charged Voltages: 4.202, 4.198, 4.202, 4.212, 4.202, 4.212
• Pack Internal Resistance-Charged: 2,2,3,3,2,2 =14 mOhms
• Pack Voltage, Post Flight: 21.88v
• Discharged Cell Voltages: 3.625, 3.655, 3.630, 3.649, 3.649, 3.672
• Discharged Internal Resistance, Battery Warm: 2,1,2,1,2,2 = 10 mOhms

Zippy #2 charged to 25.2v as indicated Hitec X2/400 dual DC Charger. Independent volt meter check indicated 25.21v

• Cell Charged Voltages: 4.202, 4.203, 4.197, 4.202, 4.202, 4.107
• Pack Internal Resistance-Charged: 3,2,2,3,2,3 = 15 mOhms
• Pack Voltage, Post Flight: 21.88v
• Discharged Cell Voltages: 3.625, 3.655, 3.649, 3.644, 3.659, 3.654
• Discharged Internal Resistance, Battery Warm: 2,1,1,1,2,2 = 9 mOhms

Voltage after power up: 25.1v

Voltage at Takeoff: 24.9v

First Voltage Warning @ 21.8v, Time 0:17:20

Observation: Voltage remained at 21.8v for much longer than usually experienced. The voltage warning did not occur until the voltage had achieved and maintained 21.8v for a considerable period of time. Unfortunately, I did not note and record that period of time. Voltage did not fall below 21.8v until 0:21:05

Second Voltage Warning @ 21.6v, Time 0:22.45

Observation: ST-16 initiates a repeated and continuous vibration cycle that is maintained until power is shut down.

Landing Voltage: 21.3v, landed manually

Post Flight Battery Temperatures: Warm, not hot. Measured using subjective method of holding battery to my cheek.

 

[Dougcjohn]

Pat, great test results & data... pulled some great results and it sounds like the conditions weren't idea so you will probably experience better results on later flights.
That looks like a great alternative from OEM in all ways: cost, physical size, and performance.

What's your opinion, found another Zippy, 5800mA but it's 7mm taller in height. The 5000mA looks like a great fit. Do you think there's another 7mm of clearance or no chance to entertain the larger 5800mA. ZIPPY Compact 5800mAh 6S 25C Lipo Pack With XT90

 

[PatR]

I believe it close but no cigar. The battery bay will tolerate a height of 47-48mm but no way will width accept anything over 95.18mm.