Battery thermal runawy alarm

[a64pilot]

Originally Posted by Ecos

Yes but all aircraft battery boxes are well vented with an inlet and an outlet for air flow.

I know there are drains, the cheap crap Gill battery on my Maule leaked and stained the paint on my 1 month old new fabric and paint job, but I don’t remember an air inlet source.
I’ll never have another Gill
The drain was part of the battery, just like a Mazda Miata battery and a Toyota Prius battery have hoses connecting the battery to the outside to vent hydrogen, because they are both behind panels in the trunk.
It’s battery was in the cargo compt. The venting is for hydrogen gas and acid, it’s not for cooling. The battery in our C-210 was in a black sheet metal box on the firewall in the engine compt. For example.
Cooling just isn’t as issue with lead acid, however I believe all Hybrid autos have battery cooling fans due to high amp charging and discharge, I’d assume pure electric Auto’s have battery cooling systems too.

I’d bet that battery fires on lead acid banks are 99% actually wiring induced and not the result of thermal runaways.

We have all seen and usually smelt batteries under charge with a bad cell, they overheat of course and usually boil the cell that has shorted and stink to high heaven too.

Now I’m not saying there is anything wrong with an overheat sensor, it can’t hurt.

[model 10]

[QUOTE=a64pilot;2944484]I know there are drains, the cheap crap Gill battery on my Maule leaked and stained the paint on my 1 month old new fabric and paint job, but I don’t remember an air inlet source.


FAA 43.13-1B par11-21c " You must maintain positive ventilation" They also mention having a sump jar for acid spills. Some older twin Cessna's had a small compartment in the bottom of the batt box for baking soda.
We switched out a bunch of NICad batteries and would install 2 great big Gill batts with sump jars to replace just one ni cad.

[hzcruiser]

Originally Posted by AndyEss

[...] A battery temperature record might in and of itself be useful to monitor battery health. Many boats have plenty of computing and data storage capacity to implement this.
Another line item to my wish/to-do list.

Sure is useful, e.g. the last 7 days or even the last year, showing the seasonal changes here in Oz. Separate graph for each of the batts of course.

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Originally Posted by Dockhead

My problem seems to be inadequate air circulation (like none) in the aft bank which is under my bunk. The forward bank has never done this; this is the second time with the aft bank.

As mentioned, a small fan could mitigate that problem, maybe in conjunction with a temp sensor so it's not running 24/7.
A high temp alarm would certainly be useful to avoid serious damage.