P4 battery mod

[Afastboy]

I've only had one flight with the multistar also, vps is taped off with electrical tape and Velcro over that, but many with the g6 packs. I remember after modding the p4 I had a couple good flights then had gotten the error only to recalibrate vps and never seen the message since.

After reassembling, it seemed to me that the front vps sensors set lower in the sight holes then before I touched it. Maybe that was the reason to recalibrate.


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[dirtybum]

I had that error after doing the birdside mod and had to recalibrate vision sensors which fixed the error.


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You mean after doing the battery mod on the aircraft or did you do other mods as well? That's probably what I have to do I'm going to try tonight. It's just funny that I was able to take such an amazing flight with no problem right after the mod

 

[Afastboy]

After doing the battery mod on the aircraft I had to recalibrate.


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[dirtybum]

After doing the battery mod on the aircraft I had to recalibrate.


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Thanks bro, that's promising. Do you think it was because you taped off the VPS

 

[Afastboy]

I think it totally was the sensor forward sensor position in the shell


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[GadgetGuy]

I guess the mod was a success!HealthyDrones.com - Innovative flight data analysis that matters

Yeah!

 

[IBV]

To my knowledge, no one has successfully modded a P4 battery because the terminals are at the back instead of the front, and any wires along the inside get frayed and quickly short out. The P4 aircraft itself has to be modded, and it is a royal pain to do! Two MaxAmp 2800 mAh batteries will work nicely. Two are more than 350g, but still under 500g, and work just fine.

I saw horizonfpv is doing P4 battery mods:
Phantom 4 Power Mod V3.1

 

[GadgetGuy]

I saw horizonfpv is doing P4 battery mods:
Phantom 4 Power Mod V3.1

That's a P4 birdside aircraft mod to accommodate external batteries, as opposed to a battery mod which would modify a single P4 battery to accept external batteries. The latter wouldn't void your warranty, but hasn't been done successfully, while the former will void your warranty. However, I have the birdside P4 aircraft battery mod, done by Paul at www.fpvcustoms.com
Highly recommended! He does a nice clean install and adds the battery rails, too! $250 US. A bargain. It's at least a 4 hour job!
DJI PHANTOM 4 BATTERY MOD( NO EXTERNAL BATTERIES INCLUDED) ...INCLUDES PRIORITY RETURN SHIPPING

 

[dirtybum]

It is a four hour job and it's a pain in the ***, Paul at FPV custom is charging a below value price

 

[dirtybum]

So a little update and schooling, my first flight with the battery mod went great, my very second start up resulted in foward vision sensor errors. And I noticed one of my eyeholes for the forward sensors was not sitting properly seated it's hard to tell in the picture you can see a little eclipse of the lense

So before I did before foward sensor calibration, I thought it would be best to take it back apart and figure out why that wasn't sitting properly and realign it. So that's what I did yesterday.
This time it only took me an hour to take it apart, so I'm guessing like the other aircraft it gets faster as you go. I found that one of my lead wires I soldered on was not allowing the bracket that the lens is affixed to to sit down all the way, partially because of the way I zip tied the power wire for sturdiness

So I removed that zip tie and carefully rerouted the power wires so they sit in there a little more freely and sealed it all back up which allowed the lens to sit in its proper place. I fired the unit back up without the Vps taped up or any interference with the forward sensors and it was good to go. (I never did do a forward sensor calibration )I flew out this morning with some externals taped to the legs and had no issues. Tomorrow I will try taping the VPS off and strapping a MultiStar under the VPS and see if that creates issues again. But for now I think the biggest part was the lens not sitting properly or possibly the power lead I soldered on pressing against something that should not! Word of caution if you do this mod be careful when you're close and everything back up there is a lot of antenna wires and compass wires they can get smashed in between the two frames and components.

 

[dirtybum]

The very first flight I hooked up the 5.2 MultiStar, and had no problems with the hundred percent main battery shutting off or having to restart a couple times. The second time I tried the MultiStar fully charged to 4.35 and a fully charged main battery, I had to restart so many times that the main battery drew down to 90%. So the next time I hope up the MultiStar or any LiHV i'm going to try only charging them to 4.30 and see if that changes it

 

[GadgetGuy]

The very first flight I hooked up the 5.2 MultiStar, and had no problems with the hundred percent main battery shutting off or having to restart a couple times. The second time I tried the MultiStar fully charged to 4.35 and a fully charged main battery, I had to restart so many times that the main battery drew down to 90%. So the next time I hope up the MultiStar or any LiHV i'm going to try only charging them to 4.30 and see if that changes it

It will likely need to be slightly less than 4.30, as the main battery will need to already be fully freshly charged to 4.30 itself (and you can't top it off, if it is currently less than 100% but more than 96%, unlike a P3 battery!), and the external(s) will always need to be less than that internal battery charge voltage, or the external(s) will start charging the main, and prevent flight. This is why using the standard MaxAmp 2800 LiPo's with the P4 is so much easier, and is Keith's first choice. Never a problem!

 

[dirtybum]

Thanks gadget, I'll keep playing with it until something works, I don't think the Maxamp 28's give me quite what I need in my climate. So I'd be just as well to undercharge the lighter Lihv's

 

[dirtybum]

The excellent maxamp 2000's i ran this morning was only giving 29-30 min.
I need a battery combo that'll give me 36+

 

[GadgetGuy]

Thanks gadget, I'll keep playing with it until something works, I don't think the Maxamp 28's give me quite what I need in my climate. So I'd be just as well to undercharge the lighter Lihv's

If anyone can figure out how to work around those limitations, it's you! Keep us posted!

 

[GadgetGuy]

The excellent maxamp 2000's i ran this morning was only giving 29-30 min.
I need a battery combo that'll give me 36+

I'm getting around 25-30 minutes with the 2800's, on flights of 65,000 feet total, depending upon the speed and the video subjects along the way. That's comparable to my old motor P3P's, which won't set any records, but now both setups finally deliver the stable FPV I need out to 6+ miles, while still allowing me to make it all the way back home!

 

[dirtybum]

If anyone can figure out how to work around those limitations, it's you! Keep us posted!

Yeah, strange because that first flight. I had a fully topped off 5.2 MultiStar at least 4.3 far across the board and I warmed the air crap up with a starter main battery, then after warm-up was over and safe to fly GPS popped up, I shut that battery off pulled it out and put in a fully charged main battery. As soon as it said GPS ready to fly I plugged in the 5.2 and immediately took off and didn't get any battery errors. So I don't know if taking off immediately prevented it from shutting the main battery off. (I know for a fact this trick works with the PIII's)

 

[GadgetGuy]

Keep at it, DB! You have the patience for it!

 

[dirtybum]

So I charge the 5.2 MultiStar to 4.33. Took off and it tried to charge the battery, so I let it hover until I got red LEDs and it landed. Swapped out for a fresh battery that was 100% ,turned on, hooked up external and quickly took off and all was good. Next I'll try charging it to 4.31 see if that makes a big difference.
HealthyDrones.com - Innovative flight data analysis that matters

 

[GadgetGuy]

So I charge the 5.2 MultiStar to 4.33. Took off and it tried to charge the battery, so I let it hover until I got red LEDs and it landed. Swapped out for a fresh battery that was 100% ,turned on, hooked up external and quickly took off and all was good. Next I'll try charging it to 4.31 see if that makes a big difference.
HealthyDrones.com - Innovative flight data analysis that matters

DB, Have you figured out a workaround to get the P4 battery to top off to 100%, if it has been sitting a few days after a 100% charge, and is now still at 97%-98%, without first somehow discharging it below 95%?