Technical Trunk mounted battery setup

Since that's a 48v. breaker at 150 amps, it's rating for 12v. is 600 amps. 150 a. x 48 v. =7200 watts. divided by 12v. and you get 600amps.

 

That is wattage math. An amp is an amp no matter the voltage.

The breaker is rated to disconnect a voltage up to 48 volts. All is still 150 Amps.

 

Its uncured butyl rubber that you wrap then use a heat gun to cure it

 

Voltage ratings on overcurrent devices have nothing to do with current ratings. Voltage ratings are given to show the arc-suppression capabilities of the device. Higher voltages generate larger arcs, and if the suppression is inadequate ionized air in the device can result in it not clearing the overcurrent and usually results in exploded devices. The rated current is the maximum, regardless of applied voltage.

Since the subject came up, I'll also point out that fusing main battery feeds is usually a waste of time and money. The only thing you're protecting against is a catastrophic short circuit to ground, which can be addressed by careful routing of the cables to prevent damage. The 150 amp 'slo-blo' fuse will likely prove to be inadequate as the 'typical' 12V V8 starter draw is 250 amps, give or take (as another example, the starter on a 1100 CC motorcycle I own draws almost 90 amps). Any hard-start scenario (hot or failing starter, low battery, poor connections) can increase that by 100 amps or more, and normal inrush current can be triple that or more.

 

Finished the firewall, 1/8” aluminum. Why, free. Its three piecce stepped at the overlap. Why three pieces, free…but seriously it was easier to make for me with only having a sawsall, grinder, and hammers.

 

Are those overly grounded drawings based on far newer technologies post Hamb era...many times sealants and gaskets are used that may effect grounding...I see it as overkill on the primitive but in today's plastic everything stuff may be relevant...

 

I’ve messed around with trunk-mounted batteries before, and running a solid ground cable straight to the block made a huge difference for me. I also ran a second ground to the frame just to be safe, and it worked great. As for grounding both heads, yeah, maybe overkill, but I guess it doesn’t hurt if you’re chasing absolute reliability. The battery box and vent line setup is a sweet touch, too—safety first, right? One thing I’ve learned with trunk-mounted setups is that getting the battery size right is a big deal. A good fit keeps it secure, and you don’t end up fighting with space. If anyone’s curious, checking out group 26 battery dimensions before starting can save a lot of h***le.

 

Here's my 2 cents. I was in aviation for 50 years. Found a old NiCad battery box in the trash. I have seen them on Ebay. Came with all the goodies. Quick disconnect, vent system, and made of stainless. Bought a battery that fit, made some connector cables and spacers. The lid is insulated so even a rollover won't let it short out. I can pop the trunk and disconnect all power with a twist.