How do people mount a Lipo battery to their case, keeping in mind it might get hot?
I am making a battery powered bluetooth MIDI controller. The Feather M0 Bluefruit I am using is only interfacing with an 128x64 Oled and 6 foot switches. The Oled only draws 0.08W when fully lit so I don’t think it will be a problem, but I would like to hear from anyone if you think it will be an issue.
P.S. I am making it out of wood for strength and so the Bluetooth signal won’t be blocked by a metal box.
Hi John,
I like to keep any LiPo’s stuck on my projects ready to rip off at a moment’s notice. A bif to velcro on the battery and some on the underside of the box might work here, I also like the velcro reusable zip ties if something is a bit more sensitive(i.e. LiPo’s).
PS: Awesome idea making it out of wood, I’d also be weary of the antenna and protoboard having some interference, check out this post: ESP32-Cam WiFi Interference Issues with Makerverse Protoboards
Thanks for your feedback and links. I think I have some velcro in the garage which I could use. I was also wondering about dissipating heat from the battery. I’m thinking it wouldn’t get too hot with my usage but I am not sure.
Hi John,
Depending on the Bluetooth setup I think the radio would be using a bit more - still the overall power usage of your system shouldn’t be too high so the heat generated inside the battery would be low.
More on calculating it below:
The heat that the battery generates would be equal to the current flowing through it squared multiplied by its internal resistance(same as a resistive element). Unfortunately, it isn’t as easy as putting your DMM on resistance mode and measuring it, Sparkfun has a good guide: Measuring Internal Resistance of Batteries - learn.sparkfun.com
As long as the battery has a vent and some airflow it should be good - doing some real tests are often quicker than doing the maths (I think it was the Safety Third podcast where they mentioned its easier jumping in and trying it instead of working it out - simulating might be worth tho/depends on the project).
Thanks Liam. I appreciate your kind thoughts and help. I am a retired Physics teacher so I could have calculated a value like you suggested but I realise that there are many variables that will influence the result, like you mentioned.
I guess I was hoping someone had used one in a similar situation and could let me know how it went. I like your idea of vents, so I’ll make sure there can be air flow by not joining the wood properly and leaving gaps. 
No worries John! I’ll be honest I had a little giggle about your solution, I have a feeling that will creep into my vocab ahaha
Also, all my builds are prototypes…
Just reporting that the build worked and I am happy I now have a battery powered foot switch that sends MIDI CC commands to my iPad and so I can turn things on and off with my feet while playing guitar. The wood feels strong and able to be stood on and lets the bluetooth signal through.
Here’s the innards…
Hey John,
Looks great! I’m pleasantly supprised the Bluetooth gets through the Protoboard.
I’m keen to see it in action!!
Thanks. The blue tooth signal makes it through several walls in my house so it won’t be a problem as the pedal will be within metres of my iPad when I use it.
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