Solo Battery Drawing

[RichWest]

Here is a sketch I made of the Solo battery. I didn't place dimensions on the drawing since my purpose was for other reasons. I did however place a scaled cube as a dimensional reference.

For you people that have dissected the battery (@Soloing ), let me know if the battery cell placement or count is incorrect, I just went off the pictures that were offered up and then assumed some aspects.

For the most part everything is to scale or at least a close representative. Use at your own risk, no accuracy is implied. Hope it helps someone else...

EDIT: Changed drawing, battery depicted with 4 cells...

 

[Pedals2Paddles]

Shouldn't there be 4 cells in there?

I'm wondering if anyone has thought about swapping the cells with, for example, cells from a HobbyKing 6000 or 8000mah multistar battery.

 

[RichWest]

Shouldn't there be 4 cells in there?

Updated the drawing to 4 Cells. Thanks for the correction.

 

[franknitty69]

thanks. this will be useful for me.

 

[PdxSteve]

They do have a to-scale 3d cad file of the battery. I printed one and it fits the battery compartment perfectly, with the sliding locks and everything It does have one strange hump in it where the LEDs normally are, I believe it's part of a keep-away zone for people developing batteries. See the link under Mechanical Interface.

Battery Bay | 3DR Solo Development Guide

 

[PdxSteve]

I'm wondering if anyone has thought about swapping the cells with, for example, cells from a HobbyKing 6000 or 8000mah multistar battery.

Someone has done that on this forum and posted about it. I think they swapped for an identically spec'd battery pack though. Not sure you can use anything else safely without reprogramming the BMS chip in the battery that tells it all the parameters (which tells it how to charge, etc). I'll be playing with that after my charger is complete.

 

[Pedals2Paddles]

I guess it would depend on if the smarts in the battery cut off the charging based on voltage or based on MAH put back in. If it's just voltage, than an increased capacity wouldnt effect it. You'd need to change the capacity via Tower or Mission Planner of course. But if it keeps track of how many MAH were put back in by the charger, that will certainly screw up everything.

I wonder if putting an XT60 and balance connector on the outside of the battery, effectively bypassing the battery's own brain, would make custom charging easier. I do not know what effect that would have on what the battery reports to the Solo though.

 

[RichWest]

thanks. this will be useful for me.

Was hoping you battery guys could use it, if only to stimulate an idea...

They do have a to-scale 3d cad file of the battery.

Where I come from, my world is in 2D and then we build to 3D...

Good to know various files are available. Wish they just made a master list for the entire set of drawings available. pdf's wouldn't hurt my feelings either...

 

[PdxSteve]

Yes, I want to print the shell and make some changes for projects

 

[RichWest]

Wow how time flies and now summer is full blown here on the Gulf Coast.

When I created the drawing my main idea was to place holes around the upper battery shell to help vent the battery's built up heat in the heat of the summer. This weekend was near 100 based on the truck temp, batteries were exceptional hot once landed at 25%. No way the smart battery would have charged at that temp and not while sitting in a hotter truck.

The Aussies said that the batteries were GTG in the heat of their summer. I'm sure my aging batteries are less efficient now, so they may develop more heat as they discharge. I really don't know....

So now I'm cogitating venting the batteries to provide some means to release the built up heat in flight and cool quicker once depleted. With the clearances seen in the drawing, I'm thinking two to four holes just rear of the plug side as an inlet and then two larger holes as exhaust back on the tail near the LEDs. All these holes would be placed on the sloping portion of the battery housing.

I'm not wanting to get too exotic, no induction hoods, just simple holes. Curious, from anyone's personal experience with air flow through a "box", what should I be considering and any opinion based on the battery layout as shown in the drawing? Obviously structural integrity is very important, so there is no consideration to have it look like swiss cheese or remove the top completely. I'm just looking at improving the air flow through the battery. Also, not interesting in having the battery play a "G" note as it flies... So hole shape may play a part....

Just something to ponder...your welcome....

 

[Pedals2Paddles]

Just drilling holes won't cut it. You'd need a small scoop on each of the front holes to force air in.

Unfortunately I think the only thing that will cool off is the area AROUND the battery cells. Look at conventional hobby LiPOs. There is no smart brain and no enclosed hard shell. They get hot even with air flowing directly over them with only the plastic wrap holding it together.

 

[PdxSteve]

At those temps I don't really think it would help much with just passive airflow. If you have a battery pack already opened up still, maybe try anchoring the guts in the shell temporarily with zipties around the entire battery/solo belly and leave the entire top of the housing off and use that for the ultimate test before drilling holes. With temps above 90, I just don't think there is enough difference in temp to cool them down to a level fast enough where it would be beneficial. It might be better to strap a small hand sized gel based ice pack to the top of the battery with a cloth in between to absorb any condensation.

 

[PdxSteve]

Also @RichWest thank you very much for all of your experimentation trying to improve performance and collect data. A lot of us really appreciate the time and you put into it, and also the time it takes in reporting back with data/drawings/pics/diagrams.

 

[RichWest]

I've encountered a fast drain battery in my collection, so I'm debating on a warranty claim or tearing it up with this project. Heat has always been an issue for me since my DJl days. As they say, nothing ventured, nothing gained. Besides, this is just a conversation, no harm in the discussion of the pros and cons.

Like you, I'm just giving of my efforts to help anyone interested benefit in their Solo experiences. Me, I like to tinker around with stuff, so I do it regardless of anyone listening. Wish it were an infection though....

I do appreciate you saying such. I appreciate your perspective on a variety of topics we have covered here. To you, I thank you for all that you contribute to the Solo experiences. Besides, anyone that would listen to Siouxsie can't be all bad....right? (spelled it right this time!!!)