My SOLO Battery mod

DocBr · Aug 30, 2020

hello !! I want to share my version of the power modification. I have 10 original batteries, but 5 of them last less than 13 minutes of flight (with camera and gimbal). Therefore, I'm already looking for options for replacement with alternative batteries. But I still want to use the original batteries while they are still alive)). There is a lot written about it on the forum and it is very useful!) I decided to do something universal for mounting batteries with BMS. I do not want to change the settings in Solo now, so I will monitor the power supply by voltage, if the battery capacity is greater than 5200.

Battery Tattu 6750 is probably the largest li-po that can be compactly placed ...
flight time in mixed mode with gimbal and camera 20.5 minutes to a discharge of 3.4 volts per cell.

Another option is a li-ion 4S3P

I have a few more dead batteries from which I can use the BMS and the case.

RichWest · Aug 30, 2020

Not meant to be criticism, just an observation from the photos. You have minimal solder bonding your wires to the +/- battery termination pads. Your photos indicate only a surface attachment to the original solder. The discolored flux is an indicator of excessive heating time.

Preference is a larger soldering tip. The pads and wires are big heat sinks and will suck up the heat on small tips. You can actually damage the board by having to soak an iron longer on the pad to make wet. Ideally a tip that is 1/2 or greater the width of the solder pad. The battery manufactures use a 60-80W iron with a 1/2" wide chisel tip, it takes them maybe a second to make the connection.

And as well, flux is your friend, within reason, more is better. If re-working oxidized solder use a rosin type. If clean/shiny, then any no-clean flux will be fine. Either way, clean up your solder joints of any flux residue.

Nice fitment of the 6750 into the battery case. The retaining clip is also a nice touch. Thanks for sharing your build.

DocBr · Aug 31, 2020

RichWest said:
Not meant to be criticism, just an observation from the photos. You have minimal solder bonding your wires to the +/- battery termination pads. Your photos indicate only a surface attachment to the original solder. The discolored flux is an indicator of excessive heating time.

Preference is a larger soldering tip. The pads and wires are big heat sinks and will suck up the heat on small tips. You can actually damage the board by having to soak an iron longer on the pad to make wet. Ideally a tip that is 1/2 or greater the width of the solder pad. The battery manufactures use a 60-80W iron with a 1/2" wide chisel tip, it takes them maybe a second to make the connection.

And as well, flux is your friend, within reason, more is better. If re-working oxidized solder use a rosin type. If clean/shiny, then any no-clean flux will be fine. Either way, clean up your solder joints of any flux residue.

Nice fitment of the 6750 into the battery case. The retaining clip is also a nice touch. Thanks for sharing your build.

Thanks for the advice! .Well, I soldered it .. I have a tip diameter of 8 mm and a soldering iron of 80 watts, rosin flux .. The quality of soldering .. yes, I agree) is not good .. I was in a hurry, I was afraid to overheat)) and maybe not enough flux. I don't often hold a soldering iron in my hands.)

next job - welding li-ion ..) It's harder. ) I want to collect 4S3P 9000

RichWest · Aug 31, 2020

I'm no expert, I've had my fair share of soldering learning experiences. Motor pods and batteries, both see a lot of amps/heat. Just didn't want you to experience a failure at some point.

Proper tools for spot welding li-ion seems more consistent than soldering, at least for me. I look forward to your shared experience with a li-ion battery pack build.

DocBr · Aug 31, 2020

a friend bought this .. It's rubbish!
Burns after several welding points!
Need something more reliable ..

RichWest · Aug 31, 2020

I'm not there yet, but pulse length and contact pressure seems important. My only experience to date is spot welders for sheet metal fab...a little over-kill for welding batteries.

nvpowerdoc · Sep 25, 2020

I need to do this. Six dead batteries.

Mike Boland · Sep 25, 2020

The BMSOne is proving to be a good solution for me.
Always had calibration issues with the Solo BMS fitted to different batteries and it was always a clunky (technical term) fit and look on the Solo.
So I opted for an internal BMS fitment that mean I can just plug any old battery in.

DocBr · Sep 25, 2020

Mike Boland said:
The BMSOne is proving to be a good solution for me.
Always had calibration issues with the Solo BMS fitted to different batteries and it was always a clunky (technical term) fit and look on the Solo.
So I opted for an internal BMS fitment that mean I can just plug any old battery in.
View attachment 11431 View attachment 11432

yes it's a good thing! And it will be in the future, when all the original Solo batteries die .. But while there are several more Solo batteries in good condition, for 15 - 17 minutes in the air, the BMSОne should be connected separately, without replacing the original connector.

Mike Boland · Sep 25, 2020

I fully agree, and I still have one original battery left with some life in it, which is why I run the other method of installation of the BMSOne.

DocBr · Oct 26, 2020

Test for flight time 20 min and range 4.25 km on a modified smart battery.

makatanav · Oct 27, 2020

what's the purpouse of that carbon fiber thing around gimbal?

DocBr · Oct 27, 2020

makatanav said:
what's the purpouse of that carbon fiber thing around gimbal?

it is a thin light plastic from the office folder ..)) At high wind speeds, the sharp acceleration of the propeller speed by the flow of air presses on the gimbal and there is an oscillation of the camera. I noticed that with such protection these oscillations do not exist. Gimbals can not be adjusted - the power of motors for example ..

Kkjensen · Nov 1, 2020

Mike Boland said:
The BMSOne is proving to be a good solution for me.
Always had calibration issues with the Solo BMS fitted to different batteries and it was always a clunky (technical term) fit and look on the Solo.
So I opted for an internal BMS fitment that mean I can just plug any old battery in.
View attachment 11431 View attachment 11432

I like the look and sound of this. Does someone sell the parts for this mod? I'd sure like to read up on it. I was just about to start comparing the specs on my milwalkee 18v battery packs to see if there would be any chance of a mod to convert to batteries available at any home depot...

Mike Boland · Nov 1, 2020

The BMSOne is designed to fit into the GPS bay of the Solo.
The rest I just 3D printed to mount the GPS on top.

Kkjensen · Nov 1, 2020

Mike Boland said:
The BMSOne is designed to fit into the GPS bay of the Solo.
The rest I just 3D printed to mount the GPS on top.

I'm just reading through that other megathread now! Is this the place to purchase? JB/BMSOne LiPo Edition

Mike Boland · Nov 1, 2020

JB sells the the BMSOne in a case so you can switch between std Solo batteries and normal batteries by using the adapter box.
I purchased the boards direct from the designer at mad hacker.org and 3D a box for one solo to be a reversible mod, the other I did a new GPS shield and cover for the top.