Dual Battery Mod

[chazz]

This MS4 LiPO is 320g. I take it you are wanting to use a LiHV though?
Multistar High Capacity 4S 4000mAh Multi-Rotor Lipo Pack

Yes I have MS4 lihv but I don't believe the weight that is listed in your link for that non lihv...Hobbykings weights are messes up...The lihv's are usually lighter...I believe that battery's weight to be north of 355 g's

 

[Strat]

Good job on the split. I guess time is expected to be lower than a single. But hopefully you'll get better time with calm or no winds. Is the wiring correct for split batteries? Any pointers?View attachment 70446

Yes, but not sure if you are deciding to pull all the cells apart as all you need to do is split it at the yellow mark in my pic with 8" of wire and then add a new balance lead (longer) or some length to each wire of the balance lead.

 

[mandalay]

Yes, but not sure if you are deciding to pull all the cells apart as all you need to do is split it at the yellow mark in my pic with 8" of wire and then add a new balance lead (longer) or some length to each wire of the balance lead.

No I'm not pulling all the cells apart; 2 cells in each side. So I'll split it at that yellow mark and add longer cables for balance lead and XT60 connector. I'll likely try with an MS5200 first and see how it goes. But I'll need to get all the materials like 4s balance lead and PVC heat shrink. Thanks for your reply and pointer, Strat.

 

[dirtybum]

Record cold lately. Gonna be 20-30 degrees this next week though. I think the main bat will stay warm for a long distance flight.
I wonder if little hand warmer bags strapped around the external will be affective for LD flight? Wonder if it will warm it too much!


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[chazz]

Yeah I wont be splitting a battery again...I seem to have the same problem DB had losing time after doing it...Took it for a short flight and the DJI battery had 3.95V per cell and the MS8 had 4.02V per cell after the flight...it was a 14 min flight to 66%...I could tell the difference instantly when the timer went from (---:---) to (25:00) within the first minute...Before the split it took maybe about 7min before it switched...splitting the battery, adding the longer leads and or the solder joints must have added some resistance...The battery used to drain evenly with the DJI battery...Live and learn...

 

[Digdat0]

Yeah I wont be splitting a battery again...I seem to have the same problem DB had losing time after doing it...Took it for a short flight and the DJI battery had 3.95V per cell and the MS8 had 4.02V per cell after the flight...it was a 14 min flight to 66%...I could tell the difference instantly when the timer went from (---:---) to (25:00) within the first minute...Before the split it took maybe about 7min before it switched...splitting the battery, adding the longer leads and or the solder joints must have added some resistance...The battery used to drain evenly with the DJI battery...Live and learn...

would be interesting to do a back to back, the split 8.0 and a single 8.0 and do a hover test, curious what the difference is in terms of time for flight. Weird that splitting a pack drops the power as much as it does, seems like it should be just as fine, but ya never know!

 

[chazz]

would be interesting to do a back to back, the split 8.0 and a single 8.0 and do a hover test, curious what the difference is in terms of time for flight. Weird that splitting a pack drops the power as much as it does, seems like it should be just as fine, but ya never know!

I cant compare yet I loaned out my MS8 ill try that when i get it back...I may take the split apart and check my solder joints as i had an issue soldering the leads on the battery tabs...I think they are made of aluminum an i had some issue getting the solder to stick..I just bought some flux and solder on eBay for aluminum to give it another try..We'll see how it goes...

 

[dirtybum]

HealthyDrones.com - Innovative flight data analysis that matters

Flew a 8.0 multistar on loan from Chazz today. Wind was stronger than I would even bother with on a normal day but it was the nicest day I've seen in a month, 7-13 mph 32 degrees. The bat shows promise given these winds.
It seems heavy and akward but it flies[emoji41]


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[chazz]

HealthyDrones.com - Innovative flight data analysis that matters

Flew a 8.0 multistar on loan from Chazz today. Wind was stronger than I would even bother with on a normal day but it was the nicest day I've seen in a month, 7-13 mph 32 degrees. The bat shows promise given these winds.
It seems heavy and akward but it flies[emoji41]


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Nice DB glad to see you got it out...the weather does suck and the tank battery likes to get pushed...I think on a nice warm calm day you get 39 to 40 min..I took the ms6 out yesterday and got 36min to 8%. not too bad

 

[dirtybum]

Got the 8.0 ms out again last night, mainly to test a compass error I was getting intermittently. Turns out the compass error was caused by the large 8.0 battery because I had the leads running to the same side the compass sits on.
Like this..

I ran out 40000 and had no errors once I flipped the bat around and had the power leads opposite the compass!
Bat shows promise, had it back to me at 40%
HealthyDrones.com - Innovative flight data analysis that matters


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[Alan Russel]

Hi DB that's some battery, I have been running in my MS5200 lihv and just biding my time for a calm day to see how it performs on long flight...cheers.

 

[chazz]

I bought a meter to measure IR and I was a little surprised at what I found, or didn't find..A new MS8 pack has an IR of 22.5 Milli/Ohms and the MS8 Split has an IR of 23.7. Its not much difference based on its performance, but it WAS only one flight with the split...One cell on the split was a little off at 5.68 and the other 3 were at about 4.4 but doesn't seem like much difference. I plan on seeing if i can fix that with some aluminum solder and flux i ordered to solder the leads on the battery tab a little better. The solder didn't seem to want to stick to it...IDK, maybe the freezing temperatures affected the battery..Ill have to test it when its a little warmer...

 

[Ed209]

The Harris flux makes no difference. It does allow the bond to lipo tabs to be secure but that's about it. Splitting a 4S into 2x 2S just puts more strain on the 2S packs even though they are ultimately a single 4S once wired up in series. Been there done that a year ago. All the tests are in this thread.

 

[chazz]

The Harris flux makes no difference. It does allow the bond to lipo tabs to be secure but that's about it. Splitting a 4S into 2x 2S just puts more strain on the 2S packs even though they are ultimately a single 4S once wired up in series. Been there done that a year ago. All the tests are in this thread.

I really don't understand what would cause the split not to be as good...I did re-solder with the Harris flux and it showed an improvement on the meter...before I re-soldered, the resistance on the pack was 23.7 Milli/ohms and after its 21 which is better then then the new MS8 i have...The cell that was 5.68 is now 4.77 and the other 3 are in the 3's...
I also checked the junk 5.2 split i bought awhile ago against the MS5.2LiHv and the difference in the resistance quite a bit...The 5.2 split has a resistance of 33.6 and a real C rating of 13 and the MS5.2LiHv is 22.5 with a real C rating of 16...

 

[Ed209]

I really don't understand what would cause the split not to be as good...I did re-solder with the Harris flux and it showed an improvement on the meter...before I re-soldered, the resistance on the pack was 23.7 Milli/ohms and after its 21 which is better then then the new MS8 i have...The cell that was 5.68 is now 4.77 and the other 3 are in the 3's...
I also checked the junk 5.2 split i bought awhile ago against the MS5.2LiHv and the difference in the resistance quite a bit...The 5.2 split has a resistance of 33.6 and a real C rating of 13 and the MS5.2LiHv is 22.5 with a real C rating of 16...

How are you checking them? Are your leads permanently soldered like a 2x2S so you're testing at the XT60? I believe the reasoning is that when you split the 4S to 2S the batteries take a heavier hit from the current that is required. I tried to get a clear answer from engineers at work (battery lab) and I never got a straight answer. But all the mathematics and propeller heading aside, no matter what battery you split, it ALWAYS sucked. So much that I abandoned trying to figure it out anymore.

 

[chazz]

How are you checking them? Are your leads permanently soldered like a 2x2S so you're testing at the XT60? I believe the reasoning is that when you split the 4S to 2S the batteries take a heavier hit from the current that is required. I tried to get a clear answer from engineers at work (battery lab) and I never got a straight answer. But all the mathematics and propeller heading aside, no matter what battery you split, it ALWAYS sucked. So much that I abandoned trying to figure it out anymore.

Yes I'm checking through the XT60 connectors and the balance lead for individual cells. The meter measures under a load...I did a lot of research before i bought it and i believe it's an accurate test of the quality of the battery...I AM checking them at storage voltage so fully charged the results would be more accurate or show better numbers but to compare them I think its ok... It also measures the real c rating of each cell and also max safe continuous current...there really isn't much difference between the split and not split..at least for the one i split not the 5.2 that I bought, that ones junk...

This is the meter, watch the video you can see how it works and everything it measures...
Universal ESR Analysis Meter - ProgressiveRC

Really, the only thing I can think of why, at least my split, wouldn't be as good is ya know all that wrapping and those plastic plates on the sides of the battery, well maybe taking all that off causes the cells to be more exposed to the cold...I mean there def is more surface area exposed to the temp...electricity (or me) doesn't like to flow in the cold..My flight test was done in freezing temps...Maybe forgetting about the added weight from those plates and all the wrapping and putting them back on would be better. IDK...

 

[chazz]

I really don't understand what would cause the split not to be as good...I did re-solder with the Harris flux and it showed an improvement on the meter...before I re-soldered, the resistance on the pack was 23.7 Milli/ohms and after its 21 which is better then then the new MS8 i have...The cell that was 5.68 is now 4.77 and the other 3 are in the 3's...
I also checked the junk 5.2 split i bought awhile ago against the MS5.2LiHv and the difference in the resistance quite a bit...The 5.2 split has a resistance of 33.6 and a real C rating of 13 and the MS5.2LiHv is 22.5 with a real C rating of 16...

K, what i said here wasn't accurate...Re soldering the leads was not what i now believe had an affect on the resistance...I checked the resistance as soon as i was done working on the battery and the battery was warm, at least warmer then when i first checked it...The battery had time to cool and its now back to the original resistance it was before I re soldered the leads or at least close to that...I then checked the new MS8 and the resistance on that pack was higher then when i first checked it, so I did a little test. I took the battery upstairs and put it on a heated vent for a few minutes... The results were before heating resistance 23.4 Milli/ohms and after 18.9...So if comparing or checking batteries, i would say it's important to have them at the same temp and at the same charge...it really shows how a few deg. can affect the battery...So what ED said "The Harris flux makes no difference" is accurate or at least I cant really tell...But the stuff does work great to solder to the tabs and I wouldn't try splitting again without it...

My first test flight, in freezing temperatures, with a naked carryon had to be hard for the battery and is probably one of the reasons it didn't keep up with the dji battery...

 

[rulppa]

Umm.. long read, i've been idling from the forums, flying now and then tho.. had almost a year to catch up. Spend a day or few reading with your latest tests and findings, including pages 30-113 here, lol..

I was going to 'refurbish' my phantom, swap new covers etc, ditch the birdsize-amp and other things.. which i did (****) and sell it in original shape since i have un-modded new gl300a rc laying around.. and get p4p. Well.. got here to see whats up with p4p (mod-wise), erm.. absolutely nothing!!&€#" so that seemed bit boring, even though it has great features and killer camera.

Ordered few MS 5.2 lihv's and maxxrange panel (holy ****, it's HUGE) .. not a big investment since i have boosters, brackets and all the crap needed to have some fun again. Seems like one more round for the old p3p, thanks guys..

 

[NoBiffBetter]

Hey guys, I just ordered the maxx UAV maxx range BIG panel antenna for my p3a.. I also ordered the clean install kit.. It should all be arriving tomorrow in the mail.

I will have the setup complete and ready to fly by Tuesday. I want to get into long range flying and have always been super intrigued by it. Now that I have the nessesarry equipment/setup for long range, the next/final thing on my list is a battery mod. And this is why I'm making this post.

I plan on either modding one of my own battery's, I have 3. I don't really want to mod the aircraft as it is still under warentee but also cuz I just don't wanna go in there and mess with anything and permanently alter the internals of the craft incase I ever sell it. So this leaves me with modding the battery itself.. I either plan on buying the whole kit online, (fpv customs) with the saddle batt holders with 2 lipo battery's and a brand new modded battery pack for like 250$ or I may just do it myself.

I am not new to common battery's, lipos, battery chemistry, wiring, soldering, or parallel and series connections. I have all the basic knowledge I believe to do this mod..

My question is ..2 of my battery's are authentic, and the other is a knock off China batt, I got it for Xmas from my mom (she didn't know there was a difference when she bought it) I have flown with the batt like 8 times now and I havnt had any issues, I get the same run time out of it as the 2 other original p3 batts I have... So I was thinking for my first mod, why not start with the cheaper lower end knockoff batt, incase I mess something up, figure it would be the perfect test subject lol. But will this be ok? Or do you guys only recommend modding an original phantom battery? Also Iv read there is like a glue on the solder connections ?

Also, since the battery's will be in parallel, Howcome there are so many ppl running regular lipos with the stock lihv batt? Cuz when fully charged the lihv will have an extra .15v Aprox, than the regular lipos, so once connected in parallel isn't the extra voltage from the stock battery gonna damage the other two regular lipos connected in parallel? I feel like over time this would be dangoirus and can destroy the other two lipos.

I had planned on running 2 lihv lipos with the stock battery when I do this mod, this way when all 3 batts are fully charged they will all be at the same voltage roughly and won't have a ton of current flowing once connected. If I do go with lihv, what mah should I use? Cuz I know you don't wanna weigh down the quad too much or else you really won't be gaining much extra time in the air.. So clearly the weight of the battery and mah are the two biggest key thing to pay attention to when doing this mod.

Lastly, what are the best side arm battery holders? And where do you guys buy yours from?

Any advice on these matters would be HIGHLY appreciated!

Thanks guys!


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[mandalay]

But again I can't really seem to find anything worthy of showing step by step modding on a p3 batt..

Any advice on these matters would be HIGHLY appreciated!

Thanks guys!

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Look at the 2 links in post 1455 below which should answer a lot of your questions. The easiest mod is power clip since you can use it with any batteries. Make your own for $10 or buy one for $45.
http://www.phantompilots.com/index.php?posts/1046085/