openinverter forum

Hello,
i want to put my battery in a sealed box. A vent for excess pressure is not a problem. What I'm afraid of, however, is if my cooling water is leaking, or if water penetrates at another point, which then cannot drain. That's why I want to install a sensor to be warned. This would also make sense in an LDU, as it occasionally happens that the inverter runs full of water. Does anyone have an idea, e.g. from a washing machine or is there something like this in an OEM arrangement?

muehlpower wrote: ↑Sun Nov 15, 2020 2:33 pm Hello,
i want to put my battery in a sealed box. A vent for excess pressure is not a problem. What I'm afraid of, however, is if my cooling water is leaking, or if water penetrates at another point, which then cannot drain. That's why I want to install a sensor to be warned. This would also make sense in an LDU, as it occasionally happens that the inverter runs full of water. Does anyone have an idea, e.g. from a washing machine or is there something like this in an OEM arrangement?

In Volt gen II there is a small pan installed in front on the battery tray and at the lowest point in that tray its M6 bolt with O ring. its threads are sticking into the pan. If you lift the car, remove that bolt and inspect it for traces of pigment you should see nothing of the sort. In case you see some pigment or some liquid comes out of the hole you need to take the battery apart. I consider this good way to visualy inspect battery at every odd intrerval. Its not like the seals on the battery would break without a sudden action.
Of course if you had an underside strike or similar you need to check this first...

What is your intended detection mechanism? Usualy EV coolant should be non conductive.
However if you would use more ordinary coolant you could use two electrodes 1mm apart at the lowest point. They would sense liquid and you would get a light in cabin. I have seen VW coolant tanks with such electrodes installed. Maybe you can salvage them and test your concept.

Hallo Arber,
water from outside and normal cooling water with frost protection should be recognized. A drain plug is bad because my battery is attached under the floor and any recess or screw is an additional risk of damage. The car is very low!

What do you think about some rain sensor modules YL-38 / FC-37, one in every corner.
They are available on ebay for less than 2 euros!

muehlpower wrote: ↑Sun Nov 15, 2020 5:26 pm Hallo Arber,
water from outside and normal cooling water with frost protection should be recognized. A drain plug is bad because my battery is attached under the floor and any recess or screw is an additional risk of damage. The car is very low!

What do you think about some rain sensor modules YL-38 / FC-37, one in every corner.
They are available on ebay for less than 2 euros!

What about condensation? Dont you think this is a bit toyish to be trusted in a battery compartment?
Maybe you could experiment with that coolant sensor from coolant tank. You could search for it at your local scrapyard. It is a legitimate car part and should work in coolant enviroment without issues. You just need to put it at the lowest point and pour some coolant drops on it.
Maybe this
https://www.ebay.co.uk/itm/OEM-VAUXHALL ... SwSlNevVus

Or this one
https://www.ebay.co.uk/itm/COOLANT-WATE ... 0008.m2219

Or this...
https://www.ebay.co.uk/itm/Level-Sensor ... %3A2334524

I thought about using a nonconductive liquid for cooling batteries. Started doing some searching and found mineral oil is nonconductive then that lead me to people that are completely submerging their computers (for gaming?) in mineral oil.
Thats actually about as far as I got but thought it very interesting. What do you guys think? It would add weight but may be worth it if battery life is extended. I found some Youtube vids about it also https://www.youtube.com/results?search_ ... er+cooling

I thought about this for better cooling of my charger and remembered, that large transformations are filled with oil.

https://en.wikipedia.org/wiki/Transform ... prov=sfla1

As I plan to replace my charger with a TC Charger anyway, I never really looked for details.

i have tesla model 3 modules with cooling water connections that i want to use like in the tesla. For my purposes that should be sufficient. I just want to detect a leak in the system that leads to the battery box filling up. I like the suggestion from arber with the level sensor from psa ( https://www.ebay.co.uk/itm/Level-Sensor ... %3A2334524 ). Does anyone know about the pin assignment and whether there is already integrated electronics with a digital output?

We have used DKRF400 humidity/temperature probes in battery boxes. They are very robust, immune to vibration, and detect humidity changes long before you have large volumes of liquid sloshing about. You occasionally find them on ebay for ~50 euro.

https://www.driesen-kern.com/products/h ... -probe.php

This is made for EV use, according to documentation.
But it's only two pins and some resistors, not very complicated.
It at least made by a reliable manufacturer and can withstand corrosive environment.
Only $14.65

Amphenol Coolant/Fluid Leak Detection Sensor:
https://www.digikey.com/en/products/det ... 0/11311004

Just found this and thought it might also be interesting for cooling of e.g. batteries.

https://www.3m.com/3M/en_US/novec-us/ap ... ectronics/