OK after my recent posts about hot start problems, I went out for a few drives today, and after one I took off the bonnet to have a little look to check over everything and I noticed how hot the battery was to the touch. I assume this is caused by the under bonnet temps and that too is really hot.

So I need to add some vents for the engine bay. Is there a good place to put them? Is there a wrong place to put them? Is there a particular type to use? Also would it be an idea to insulate the battery.

The battery is charging at the correct voltage according to my digi dash, so the hot battery could well be the issue. I let it all cool and everything is fine again.

So, engine bay venting, how much, where and what type are being used?

Thanks

Andy

sounds like overcharging or a short circuit i would do some checks asap

You are on the wrong track battery efficiency increases with temperature. Battery efficiency is very low below 0c and effiency increases rapidly with temperature the increase in efficiency flattens but continues over about 50c.
To put some numbers on at -10c a battery only will be able to produce 75% of its' rated capacity ,
at 0c about 85%
at 20C about 100%,
at 40c about 105%
at 50c about 106%.

The reason why batteries boxes are often fitted with cooling fans is to reduce loss of electrolyte




[Edited on 6/10/13 by britishtrident]

If you do want to cool the engine bay, look at ways of letting hot air out rather than cool air in.
Simple mesh vents at back of bonnet area are sometimes all that's needed to start the air flowing through.

quote:

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Originally posted by balidey
If you do want to cool the engine bay, look at ways of letting hot air out rather than cool air in.
Simple mesh vents at back of bonnet area are sometimes all that's needed to start the air flowing through.

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Another idea Andy is to wrap
The battery in a heat reflective material

Like

http://www.thermotec.com/products/13200-battery-wrap-acid-absorbing-heat-barrier.html

I cut vents at the back of the bonnet, and in the side panels, just in front of the foot well bulkhead. Works very well

Vents

[Edited on 7-10-13 by 40inches]