Battery Tray

Are the battery trays supposed to be open in the back? How come they are not fully enclosed with sheet metal?

Yes. Airflow may help keep them cool. Won't trap water. Cost. Cheaper to build a rack than an entire box (remember, we're talking the British Motor Corp, later British Leyland).

Airflow. If the tray was enclosed hydrogen gasses would accumulate under the battery cover and pose a problem if ignited. RAY

Close it in and you'll potentially have fumes accumulating X2 - kind of like in my boot.

Don't the plastic inserts that are available enclose the area? Are they vented?

I've had two major explosions in battery boxes, both with the non-vented plastic boxes. I don't use them any more. Lucky to have my eyesight after one of them.

Bob,
Can you tell me the circumstances surrounding your battery explosions?
Yours is the only instance I've ever heard of this with my plastic bins. In my instructions, I specifically mention to leave the cable hole open so that any hydrogen gas can escape during regular use.
I have heard of batteries exploding in various cars when there was not a bin. Mostly this occurred when jumping. And these batteries flew to pieces because of internal gas--nothing on the outside.
I appreciate what you can tell me.
Cheers,
Robert