"cooking" your battery - post the nat conversion.

[herbiemercman]

Hi Guys, There is definatly a learning curve in the months and years following your NAT Conversion. Some problems present themselves in a way where you can see quite quickly what is wrong and what you have to do to fix it. This was not the case with "battery cooking", i investigated and found out after 2 years and fitting my third new Bosch battery that there is a straight line graph on the batteries life expectancy related to the ambient temperature where the battery is located.The first battery failed in 8 months and the second one in 14 months, all electrical possibilities were eliminated like charging, shorts, etc. There were other pointers for the post NAT elevated under bonnet temperatures, the the starter relay failed and i did not know it had an overheat cut out built into the circuit, the replacement did not have the cut out. The other issue was the master brake cylinder overheating and i had to make a baffle to protect this and the sound insulation on the bulk head it was radiation from the exhaust downpipe.

So i fitted two louvers one directly above the battery and the other one above the conical air intake filter, when you stop the engine after a blast the heat pours out, the bonus was they looked good.However i realized the louvers would only reduce the cooling time and not the battery temperature itself, which i was monitering with a surface pyrometer. So I constructed a sheet aluminium box, with a hinged lid and lined with ali foil coated ceramic board. This dropped the battery temperature considerably and i am confident now that the problem will be solved. Herbie. 20200405_140031.jpg (637.7 KB)

BON.&BUMP. LOUVERS.2019.jpg (630.8 KB)

[Swampy442]

A simple heat shield would have sufficed, but the majority of the heat produced is on the other side of the bay, and when driving theres lots of air flowing through the engine.\

 

Saab Turbos dont have any problems and they are located literally right next to the downpipe!

[herbiemercman]

Hi Swampy, The problem is not when you are moving due to the air flow you mentioned, the problem is when you stop, the ambient temperature rockets up and there is no air flow, also a black car in summer time and traffic jams are bad for residual heat.. The Supra's have feathering fans but rarely come on. Baffles only stop radiated heat, they do nothing in ambient temperature situations. My battery is now well protected, prior to the NAT Conversion the batteries always lasted 5 to 7 years, the NAT apparatus and engine power carries much more residual heat.Herbie.