Battery Mod Info

[Pescatoral Pursuit]

Just loitering around all loaded up.
View attachment 9601

Nice and clean. Good weight distribution.

 

[Fanti]

Damon, care to finally share your results with 8000 MS and Li Ion batts with us pls ?

 

[lake_flyer]

I am looking just for extra redundancy, to keep my I1 flying, long enough to do a safe landing, even after the main battery loses a cell. I don't need longer (but also not shorter) flight times per se.

What would be the lightest setup to achieve this? Any ideas?
My I1 is certified for a MTOM of 3.4Kg. I can't/won't exceed that.

 

[Kiwi Carl]

Hi all,

Just a quick post about these 3D printed mounts I've made for my Pro. They take these 1800mah Gens Ace lipos. 2x3S. Haven't tested flight times yet.

The rear mount simply clicks into place on the Inspire while the front mounts are held on by 3M VHB double sided foam tape.

I'm thinking of potentially selling these mounts and also making it possible for the customer to customise the battery saddle to suit theirs.

Any questions email [email protected]

Cheers.

 

[shooter505]

Don't they affect CG?


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[Phatzo]

Don't they affect CG?


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the other one available in the battery mod thread (where this should be posted) - any moderators around ?? -
is the same position but lower... should be ok... i like the idea of the snap on...
the downside i can think of at the moment is the size is not changeable when wanting to move to a different size battery... for eg: 2700mAh...

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[DJEncore]

Unfortunately the 18650 cells won't work due to their discharge voltage curve. The I1 uses LiHV batteries which maintain higher voltage during discharge. Their "empty" voltage is around 3.55v per cell. Most 18650 battery voltage fully discharged is around 2.5v per cell. LiPO is a little higher at 3.2v per cell. This is why users trying this mod have experienced the I1 battery is showing fully discharged but the 2nd LiPO battery still has 25-30% remaining. LiHV advantages are lower weight but they are very expensive, which is why we're paying DJI $199 per battery.

I'm attaching the Panasonic 18650PF (my personal favorite) discharge chart. If you know what you're doing this battery is awesome. I use it to power everything from my electric mountain bike to my Skywalker and X8. They power Tesla vehicles as well. Unfortunately DJI's design and safety limits make this and most other LiPO batteries a poor match for our goal.

Sadly, secondary batteries of LiHV chemistry are our only option. I don't have time to build up an LiHV battery at the moment but I'd venture to say that we could achieve 25-28 minute run times with a secondary battery around 5,000mah if it's of LiHV chemistry. Someone truly daring could take apart an I1 battery and use that as the secondary battery. The I1 battery is a 6s2p configuration. The individual cells have a capacity of 2,850 mah. So you could take the battery apart, desolder it and reconfigure it to be (2) 2,850 mah 6s packs. One on each side of the bird would keep it balanced. With the case removed the battery alone weighs in at 588 grams.

Just for grins I took apart a puffy I1 battery and 12 Panasonic 18650PF cells fit perfectly in place of the LiHV cells. If allowed to operate down to the "empty" voltage of 15v for a 6s cell, this would give us a 5,800mah battery weighing in at 623 grams vs 669 grams for the stock battery. It's doubtful our I1's could stay in the air down to 15 volts though. LG makes a battery, the ICR18650E1, that has a voltage of 4.35v per cell fully charged. But, fully discharged it's down around 2.5v as well. 18650s just aren't going to cut it.

18650PF Discharge Graph

• DJEncore
• Sep 21, 2016
• 1

 

[DJEncore]

I did some browsing around and these Turnigy LiHV batteries may work for this project. You'll need (2) on each side wired in series, giving you 6s 2400mah on each side of the bird. Specs say 197grams per battery but they're usually a little high. May end up around 370grams per side of the bird so 740 total to give you 6s 4800mah additional capacity for $120. High C rate is not a requirement as the inspire is only pulling around 25 amps at max power. That's less than 5c.

I successfully disassembled my puffy pack and re-welded it into (2) 6s 2350mah packs just to make sure it could be done without destroying it for nothing. $199 to go 30 minutes seems steep.... but if you want it bad enough....... Each 6s 2350mah pack weighs in at 284 grams without the battery connector.

 

[babryan]

I did some browsing around and these Turnigy LiHV batteries may work for this project. You'll need (2) on each side wired in series, giving you 6s 2400mah on each side of the bird. Specs say 197grams per battery but they're usually a little high. May end up around 370grams per side of the bird so 740 total to give you 6s 4800mah additional capacity for $120. High C rate is not a requirement as the inspire is only pulling around 25 amps at max power. That's less than 5c.

I successfully disassembled my puffy pack and re-welded it into (2) 6s 2350mah packs just to make sure it could be done without destroying it for nothing. $199 to go 30 minutes seems steep.... but if you want it bad enough....... Each 6s 2350mah pack weighs in at 284 grams without the battery connector.

I just purchased a pair of these MultiStar 10c 3s packs to try, they are 3000mah and weigh in at 188grams each. When put into series, this should give 6000mah 6s at 376grams, with similar discharge characteristics to the DJI packs.

MultiStar 3S LiHV 3000mah

 

[Pescatoral Pursuit]

I just purchased a pair of these MultiStar 10c 3s packs to try, they are 3000mah and weigh in at 188grams each. When put into series, this should give 6000mah 6s at 376grams, with similar discharge characteristics to the DJI packs.

MultiStar 3S LiHV 3000mah

When put into series you will have a 3000mah 6S configuration.

 

[babryan]

When put into series you will have a 3000mah 6S configuration.

Ah yes, that is correct. That's what I get when trying to think while half asleep.

 

[DJEncore]

Good Find! $81.23 shipped for 4 of them after I waited for the Hobby King discount window to pop up. The measurements look very similar in size to the stock DJI cells. Progressive RC is a good source for balance cables. JST-XH Pigtails - ProgressiveRC

 

[Eliphion]

Hey everyone! I purchased Ralph's mod and battery. Thing is I take off the battery holder quite often to fit the inspire into my drone crates case. I dont really want to modify the case to fit the inspire with the battery holder attached and Ive stripped out the bottom few threads on the inspire from screwing and unscrewing the battery holder all the time... so Im looking for a different solution. I know a lot of people on here use the 3m dual lock. I bought the same thing that was listed earlier in the this thread. 250 heads per sq inch. What do you think of attaching it this way to the same spot on the inspire? Think it'll hold?

 

[babryan]

I just purchased a pair of these MultiStar 10c 3s packs to try, they are 3000mah and weigh in at 188grams each. When put into series, this should give 6000mah 6s at 376grams, with similar discharge characteristics to the DJI packs.

MultiStar 3S LiHV 3000mah

I also have a pair of MultiStar 3S LiHV 5200mah packs on the way. These are 318grams each, so 5200mah (in series) at 636grams. This should go well with TB48, I hope.

 

[babryan]

Hey everyone! I purchased Ralph's mod and battery. Thing is I take off the battery holder quite often to fit the inspire into my drone crates case. I dont really want to modify the case to fit the inspire with the battery holder attached and Ive stripped out the bottom few threads on the inspire from screwing and unscrewing the battery holder all the time... so Im looking for a different solution. I know a lot of people on here use the 3m dual lock. I bought the same thing that was listed earlier in the this thread. 250 heads per sq inch. What do you think of attaching it this way to the same spot on the inspire? Think it'll hold?

I know that the 3m dual lock is strong, but I'm not sure that I could trust this. Take a look at this configuration that I'm using, it works well for me.

Tarot TL80B04

 

[DJEncore]

Multi-Star Batteries arrived today. 199grams per each 3s 3000mah battery. Here's some comparison photos against the individual dji cells that are 2350mah (142 grams). I'll give these a whirl next week.

 

[Eliphion]

Just to report back on the 3m Dual Lock. I was swinging my Inspire around last night, low altitude, trying to get the battery holder to come loose. Now I didnt try a 50mph to zero stop... but 30-0. Sharp turns, etc. It held! I was scared, but now Im impressed!

 

[DJEncore]

Tested the (2) 3000mah 3s packs in series. Landed at 8% battery life, exactly 25 minutes hovering and flying around slowly in my yard. With the stock 48 battery I can do this for 18-19 minutes. The packs took 2800mah on recharge and they were depeleted equally with the DJI stock battery (voltage-wise). I didn't notice any different handling qualities with this setup. Tomorrow I'll test flying with 4 of the packs but so far I like this setup and the security of knowing I have more time and a secondary battery in case there's an issue with the main DJI pack.

I just ordred the 5200mah LiHV packs as well, will give these a go next week.

 

[babryan]

Tested the (2) 3000mah 3s packs in series. Landed at 8% battery life, exactly 25 minutes hovering and flying around slowly in my yard. With the stock 48 battery I can do this for 18-19 minutes. The packs took 2800mah on recharge and they were depeleted equally with the DJI stock battery (voltage-wise). I didn't notice any different handling qualities with this setup. Tomorrow I'll test flying with 4 of the packs but so far I like this setup and the security of knowing I have more time and a secondary battery in case there's an issue with the main DJI pack.

I just ordred the 5200mah LiHV packs as well, will give these a go next week.

Nice flight time, the 3000mah might be near the sweet spot. I just got my 5200mah packs and tried to get a good flight today, but I my Go App updated to 3.0.0 today and everything went to crap. I did manage to get one flight with mostly hovering and slow flying on a TB48. I landed with 28% and 24 min flight time.

Once I sort out the other problems, I'll give her another try.

 

[DJEncore]

Two more test flights tonight. One I flew a total of 21:30, around 25mph, landed at 14% battery. Total distance flown was 48,177 ft (a personal record), no time spent hovering, nice smooth acceleration and climbing up to 400 feet. The other I flew around 35-40mph, full power climb from takeoff to 400+ feet, that flight lasted 16:07 minutes and I landed at 31% battery life because it was getting too dark to see. Total distance was 39,902, no time spent hovering other than landing and taking off.

I have a circuit I'll go do on Sunday where I take off, fly straight out 4 miles, turn around and come back. On a normal battery, flying at 35mph, that flight time is 16 minutes or so and I'm landing at 15-18% battery.

Interestingly, when I took off on both of these missions my time remaining started at 25 minutes and stayed there for just over 4 minutes. When I was at 86% battery it started counting down. I have 2 batteries that are modified to accept the external packs. I had flown my test hover flights with these two batteries and the 3000mah 6s external setup.

For those looking for maximum flight duration, the most efficient speed is between 20-25 mph. Hovering takes more power than flying at 20-25 mph in calm winds. I don't think I'll ever fly without these secondary batteries again. I like to go out 1-2 miles, sometimes farther, and I feel like I have a nice power reserve now and then some.