Dual Battery Mod

[chazz]

I'm not doubting that the split 8.0 produced a decent number, but I thought we already lasted to rest the fact that splitting a battery reduces the battery is the tension?


Sent from my iPhone using PhantomPilotswow my I-phone really screwed up the words/spelling on this post, it doesn't even make sense [emoji41]

Yeah after doing some tests and measuring the cells resistance and C rating with my meter I came to the conclusion that temperature plays the biggest part. 1 deg adds more resistance than any resistance added from the extra cable (I use 12awg)…With the meter I have gotten constant results showing I can hold a cell for a few seconds to warm it up and raise it one C rating and lessen the resistance from 5mOhms to 4.. I can double that improvement by holding it a minute or two…When I measure with the meter I’m in my basement at about 67 deg and just raising the temp a little improves it…Idk if you ever split a battery but I know you know what the inside of a battery looks like when you take it apart there are plastic plates on both sides and a cardboard type material wrapped around that. I thought the only purpose of it was to protect the cells from damage but what I realize now it’s also like a heat sink…The first time I split a battery I took it all off thinking man I can save 30grams this is great…The first time I flew the bird with the split in 30deg temps with no protection to the cells other than the thin shrink tubing it sucked and the worst flight I ever had as far as time with an external battery… There was a lot of juice left in the externals and the dji battery was drained... It was like wearing spandex pants in the winter to go skiing J… you also have to think after splitting the battery now you have every cell or four sides exposed to the outside temp (more surface area)….So what I did like I said in a previous post was wrap the batteries in foam packing material (like the stuff you pack glass in) and the shrink tubing on top of that…It’s like putting a thin layer of air between the cell and the tubing and the next flight was the best I’ve had as far as total distance vs time…To be fair it was warmer that day and not below freezing…I wouldn’t suggest anyone wrap up their battery in foam because now you can’t tell if the lipos swelling from damage because it’s always puffy now...All this is my observation and only after 2 flights... I guess things could change but there was such a night and day difference between the two flights I’m pretty convinced…I don’t know what’s wrong with some people splits but this is what seems to be up with mine...

 

[dirtybum]

I went through the trouble of logging back in just to say, nice find/report Chazz. Very interesting. Could be the reason early in the leaderboard unknown caller was getting record flight times while the rest of us around the world were testing the same battery and getting crap.


Sent from my iPhone using PhantomPilots

 

[Habanero]

Nice insulating the batteries make sense ... Didn't think about that, any pics of the material you used Chazz?

This?

Can't wait to try , I like to try with 12 and 10awg to see if any difference also insulation as I fly a lot in winter. To bad my dbs antenna didn't really give me any more range that windsurfers lol need to install the amps ...

 

[G Tek Fab]

I had a dual external battery set up on my Phantom FC40 back in the day and found insulating my batteries would indeed give me longer flights. I used some 3/32" foam wrap like habanero is showing. First I wrapped the batteries from end to end two layers then two layers around the whole battery. Then mummify the entire thing with some electrical tape. Worked great.

 

[chazz]

Yeah that's the stuff. I picked it up a Lowe's. The type i bought was a bag and stuck it in the corner and cut it to size making sure to cover the bottom of the battery too...I think 12 awg wire is good enough and no issues fitting it into the XT60 connectors...

This is the wire i use...Amazon.com: Hilitchi 12 Gauge 12Feet Silicone Wire High Temperature Resistant Super Soft Flexible Silicone Wire [6ft Red and 6ft Black]: Toys & Games

 

[Silverwingflinx]

these were so easy to make!! The only mod I did was to cut off the tabs of the T60 connection to fit a little more flush.

 

[Digdat0]

View attachment 77249 these were so easy to make!! The only mod I did was to cut off the tabs of the T60 connection to fit a little more flush.the positive is on top of this mod.

solder stuck on there pretty easily to make a solid connection? looks nice! how much?

 

[Silverwingflinx]

solder stuck on there pretty easily to make a solid connection? looks nice! how much?

Yes soldering was easy for you Digdat0 no cost!!! Just wanted to try it,but the copper I used is just a hair to thick.its a tight fit.will have to mod battery bay.thicker copper less resistance.the best thing about this mod is the weight compared to soldering to main board.think I might have shaved about 15gr.

 

[G Tek Fab]

My hero...

 

[Habanero]

I think 12 awg wire is good enough and no issues fitting it into the XT60 connectors...

Yup probably 12awg enough, but I don't mean on the xt60 I'm talking about the single internal lead to conect the two split packs to lower internal R ... have you confirmed that with insulation you get same performance as before splitting the 4s pack? That's what I'm hopping to achieve ....

soldering a 10awg from one pack to the other ... has any one try this?

 

[Silverwingflinx]

Yeah that's the stuff. I picked it up a Lowe's. The type i bought was a bag and stuck it in the corner and cut it to size making sure to cover the bottom of the battery too...I think 12 awg wire is good enough and no issues fitting it into the XT60 connectors...

This is the wire i use...Amazon.com: Hilitchi 12 Gauge 12Feet Silicone Wire High Temperature Resistant Super Soft Flexible Silicone Wire [6ft Red and 6ft Black]: Toys & Games

Take a look at hobbyking??for wires and conecters!!!!

 

[Habanero]

Turns out the difference it's double...

1 feet / 10awg R = 1mOhm
1 feet / 12awg R = 2mOhm

That's what online calculators report, while that's very low value for external wiring and won't make any difference, internally you are adding 1 or 2mOhm that wasent there before because they are practically weld together.

So temperature will actually make a bigger difference as per Chazz findings but after you insulate the battery and they get to optimal working temp you still be 2mOhm higher than before splitting if used a 12awg or about 1 mOhm if used 10.

To be near original will have to be more dramatic, like keeping it small like 6" or go even bigger lol little extra weigh....

Sorry for talking so much theory . Brainstorming before a project I guess. It's been a while since associate degree in electronics back in Cuba....

 

[G Tek Fab]

View attachment 77249 these were so easy to make!! The only mod I did was to cut off the tabs of the T60 connection to fit a little more flush.

What gauge and how wide are the copper tabs?

 

[chazz]

Take a look at hobbyking??for wires and conecters!!!!

Amazons cheaper..free shipping

 

[chazz]

Turns out the difference it's double...

1 feet / 10awg R = 1mOhm
1 feet / 12awg R = 2mOhm

That's what online calculators report, while that's very low value for external wiring and won't make any difference, internally you are adding 1 or 2mOhm that wasent there before because they are practically weld together.

So temperature will actually make a bigger difference as per Chazz findings but after you insulate the battery and they get to optimal working temp you still be 2mOhm higher than before splitting if used a 12awg or about 1 mOhm if used 10.

To be near original will have to be more dramatic, like keeping it small like 6" or go even bigger lol little extra weigh....

Sorry for talking so much theory . Brainstorming before a project I guess. It's been a while since associate degree in electronics back in Cuba....

My MS LiHV split batteries drain at the same speed as the dji battery...I don't think you can ask for better then that..

 

[Silverwingflinx]

What gauge and how wide are the copper tabs?

Hi procharged made these as well page 105 on this thread.i used 20awg to thick but will work if you mod battery bay.23awg and width is 5mm is what procharged used.these were just my prototype I still may want to use 23awg.positive is on top getter right don't want fireworks.hope this helps.[/ATTACH]

 

[G Tek Fab]

Hi procharged made these as well page 105 on this thread.i used 20awg to thick but will work if you mod battery bay.23awg and width is 5mm is what procharged used.these were just my prototype I still may want to use 23awg.positive is on top getter right don't want fireworks.hope this helps.

Great thank you.

 

[G Tek Fab]

Lots of great info right here on this thread for sure!
Thanks guys!
I think it's time for a definitive list in one or two posts of all the goods needed for what is now thought to be the best battery mod set up. Links are a must.

1) Battery wings or trays

2) Best battery and size for joyriding or distance flying

3) Battery clip adaptors store bought or home made

4) Anything else?

 

[Digdat0]

Lots of great info right here on this thread for sure!
Thanks guys!
I think it's time for a definitive list in one or two posts of all the goods needed for what is now thought to be the best battery mod set up. Links are a must.

1) Battery wings or trays

2) Best battery and size for joyriding or distance flying

3) Battery clip adaptors store bought or home made

4) Anything else?

If you get things, feel free to put in this Google doc. Its linked from the first post, its a Battery mod FAQ:

Battery Modification for DJI Phantom 3 FAQ

 

[Fireflyer451]

Got my Multistar LIHV batts mounted on my P3P and went for a test flight yesterday. Just to see how it handles the weight, these batts were not plugged in.

Well not so good. I got the 'motor overload' warning almost right away, on both a 5200/428 grams and 4000/356 grams . I am at 6000' so sure that is a factor compared to others on this thread.

I removed the VPS module and ran a velcro strap through it, along with dual lock on the bottom. Its all very solid, but just too much weight with those batts. If anyone has suggestions I'm all ears, but I think it is back to the drawing board.