Does anybody hope to see a dual battery mod in the future? It seems our long distance tests are limited by battery and not reception. It would be interesting to nearly double our flight times!
Potential Dual Battery Support
- Thread starter Jake Galloway
- Start date
AlanTheBeast
Well-Known Member
It would be great. LiPo's are so light - but the packaging around the drone packs are a horrid penalty. The existing Mavic pack could benefit from a camel hump or side bumps to pour in more battery at very little expense in weight and drag.
Thats a good point. I see a video on YouTube of a guy that did a custom battery mod with a secondary LiPo that had a XT60 type connector soldered to the main board. But a setup that perhaps allows dual mavic batteries would be great.
I am sure there would be some gain but not two to one. With a dual battery the flight weight would go from about 734g to 974g. This increases the power requirement and therefore the power drain. If that were linear, flight time would go from 25 min to 37 min, not 50 min and it's probably worse than that. For long range flight, which would be the main motivator, drag would also go up also requiring more power and further reduction in flight time. I am pretty sure most of the battery weight is the LIPOs themselves. Smart packaging of a dual battery could save a little but not much. There may be some optimum increase that's less than two to one. I am sure the DJI engineers were very interested in optimization and the longest flight time they could get. They may have left a little on the table but probably not a lot.
Oh I agree, it certainly wouldn't be a two to one improvement. With distance tests, every minute counts. So even a mere 5-10 minute increase would be a great benefit in my book. Then again who am I kidding, these things have incredible range and battery as it is. Far more than I would need in any practical application.
AlanTheBeast
Well-Known Member
Packaging the batteries with the current smart battery enclosure (just more volume) would result in a more modest increase in weight, I believe.
Nobody says the flight time (or range) need to double - just that, heck, we want more!
I suspect the engineering constraint was as follows: "Design a compact, folding drone that carries this camera for 20 minutes or more up to 65 km/hr and can sell in the US for $999 with 40% gross margin."
I'd add "Oh - and humiliate GoPro in the process" but I'd bet the Mavic project launched long before the Karma was announced*.
And of course I have no idea what GM goal management imposes on engineering.
*Somewhere I stumbled on a statement that said the Karma was actually designed (manufactured) by DJI for GoPro... anything to that?
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AlanTheBeast
Well-Known Member
I was just looking at the manual. The weight of the battery pack is 240 g. That's a whopping 1/3 of the takeoff gross weight. What's sick about that is that a lot of that mass is plastic container, controller, lights, etc. A modest increase in volume would not increase the dead mass very much but could allow the addition of another 20 Wh of storage pretty easily. May need some consideration for cooling however.
AlanTheBeast
Well-Known Member
Yep, I've seen a video of that in flight with transmitter mod too:
(Edit: Corrected the link)
So I'm guessing you guys don't follow the FAA rules on the "Line Of Sight" restriction. You just go fly as high and as far as you want. Please tell me where you are so I can avoid that area.
Given that the battery sits on top of the craft, I see no reason they couldn't add a small hump to increase battery capacity 20-30%. Not sure if the flight controller would need a retune with the higher center of gravity though.
Yeah I know that. But I travel a lot and just about everywhere I go I check online for "Drone flying regulations" and add my destination to the end of that, and every destination has some kind of regulation(s). I may be in the minority but I do follow the rules. Why? Because I want to be able to fly my drone. And the less problems there are the less rules there will be. Just my $.02
dsd317
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Do you drive a vehicle? If so, then I'm guessing you've NEVER gone over the speed limit; ALWAYS come to a complete stop, behind the stop line at intersections; ALWAYS use your turn signals before turning or changing lanes;
And as a pedestrian, you've ALWAYS walked in a cross-walk when crossing a street?
Some Law Enforcement Officers follow all laws my friend. What are you going to do WHEN a drone causes injury or death to someone close to you. Oh well....at least he wasn't speeding. No, I'm sure you'll be running to the nearest lawyer.
Please don't tell me we have laws and you can break them until you get caught that it's ok.
Please don't tell me we have laws and you can break them until you get caught that it's ok.
This was a fairly productive thread too.
Would be cool to see a product that would fit two batteries and snap into the Mavic's battery slot without any mods.
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