Battery cooling +

Hello everyone,

I started working on my second battery. I have slightly changed the concept of her work compared to the first one and I am working hard on her crafting.

I put a small BMS in it just for charging.

The voltage at which to turn off remains controlled by the ESC.

The question that concerns me: is it good to think about improving the cooling of the cells?

Has anyone done anything on this topic? Are there factory solutions of some of the famous manufacturers?

The case I designed is made of three elements: a 3D printed side part and the aluminum covers for top and bottom.

A possible solution Iā€™m considering is to fill the space around the cells with mineral oil for transformers. It is a dielectric with known properties and is used precisely for thisā€¦

It will be interesting to see how the BMS will feel - and if it gets flooded with oil too.

Alternatively, Iā€™m considering a quartz sand solution - itā€™s heavier and the thermal conductivity will be worse, but it will be much easier and cleaner to implement.

If a cell needs to be replaced after a while, it would be a big mess with the oil

Anyone have ideas, opinion or advice?

Please share.


If you use this pack for eFoil, I donā€™t think you will have any thermal problems to expect, without any additional cooling

Thanks for the reply,

I am currently riding with battery number 1, which is the same 14s10p configuration, only the cells are 4000mA each. The BMS is 200A in it, as several times, after a long and constant load, the BMS turns it off. Since the current is certainly below 200A, I have the temperature protection working. Which got me into a lot of trouble - about an hour of swimming in the dam pushing the board when I got out of the water, and 25 minutes of walking with a board on my back to the car.

Unfortunately, the BMS on the first battery doesnā€™t have bluetooth and I canā€™t see the temperature, but I strongly suspect thatā€™s the reason.

Thatā€™s why Iā€™m thinking and asking about cooling.

Charge only BMS is also a potential solution to your problem. Needs an extra connection and optional Fuse but wonā€˜t interrupt the VESC supply.

Thanks,
This is my intention for the second battery - 30A BMS only for charging.
I have an external fuse.
Iā€™ll probably have to rearrange the first one tooā€¦
And not to deal with cooling?
Is this your advice?

No cooling and choose the fuse big enough. I have good experience with midiOto 200A.
Fuse and holder are available from reichelt.com
https://www.reichelt.com/ch/de/kfz-sicherung-midioto-200-a-58-v-violett-imaxx-mdp200-p290809.html?LANGUAGE=DE&CTYPE=0&MWSTFREE=0&CCOUNTRY=459&PROVID=2808&gad_source=1&gclid=Cj0KCQjw0_WyBhDMARIsAL1Vz8utPtJfcLY10bADDCt9P5XyLnLT_0w2n7fsKuTrh8Uu2RFZTQCo8scaAo8OEALw_wcB&&r=1

I immediately change to ā€œcharge only BMSā€.
You can see the battery shop is set.
This is my battery number 1, red to +, black to - (directly), blue for charging via BMS to - .
Tomorrow I have plans for testing out of the box and if everything is OK, boxing and riding.

ps ā€“ careful with that battery leaning up against the wall ā€“ its contacts are untaped and its near metal tools etc. I blue tape everything until it gets properly taped ā€“ never left exposed like thatā€¦

4 Likes

Thanks,
But the battery it is Not leaning on the wall, the photo give you a wrong perspectiveā€¦ and the other side is taped with paper

After some thought, I decided against the mineral oil option. It will be very sloppy, it is not clear what will happen to the BMS, and if I have to cut 1 cell out of 140 it will hardly be possible.

Instead, I intend to use thermal pads.

Since the battery construction will have an aluminum cover on the top and bottom, it will be easy to press the pack against them and through the pads and covers to cool it.

I found on Aliexpress 120 x 120 mm 21W/mK which is very good in terms of conductivity (if they can be trusted 100%) and at a decent price.