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How To - Toyota Epic Maintenance and Upgrades


Battery Isolator

I started installation of my Hellroaring Isolator/Combiner. This is a device that allows you to use several batteries, isolating them or combining them when necessary without the usual complications. If you have a mechanical Perko switch and two batteries, and one is flat, the other will discharge across the Perko and you will have two batteries that are half flat. Typical battery isolators use diodes, they drop as much 1.4vdc . This is 10% of your total battery charge and can will cause the batteries to sulfate and fail prematurely due to undercharging. Toyotas use a small battery to start with, a series 58, and there is no easy way to upgrade because of the size limitations. I cut part of the lip around the battery opening and was able to fit an Optima deep cell, but the terminals touched the floor panel when reinstalled. it didn't cause problems, but I was not comfortable with the situation. I had problems with the instruments fluctuating, and the voltage at the dash dropping to 10.5 VDC. Measured at the battery, the alternator was supplying 14.6 volts. the dealer found some loose connections, probably caused by ME, that contributed to the problem. I decided to supplement the original battery system with an additional deep cell for running the accessories, with the original starting battery to start and run the engine. Combining different types and sizes of batteries can compound the problems outlined above, I had to use a smart device to accomplish my goals. The Hellroaring Isolator/Combiner is the solution to my issues. It is a solid state relay device that has much less internal resistance than a diode isolator. It also has the automatic switching capabilities not available with a relay setup or a Perko. Switching without protection can pop your alternator, not a cheap thing when we're dealing with marine parts, especially Toyota ones.

To be honest, I have spent so much on this project that in the long run, it may have been wiser to use a cheap isolator and replace the batteries every couple of years. It may be necessary anyway, under typical conditions. The Hellroaring isolator was 140$, the Optima deep cell marine battery was 140$, I have spent close to 200$ on wire and connectors and fuses and battery box, etc. It is a never ending story! The thing is, Toyota boats are built so well that I just don't want to half ass anything, it sticks out, so I end up doing things more than once.

Anyway, here is the url to the page www.hellroaring.com

Here is my setup. I mounted a Group 24 battery box minus lid to the back side of the wall on the left side of the storage compartment. The battery and box will slide back in between the hull and the cooler. The isolator circuit and wiring will be invisible behind the panel. Some of you may have your ballast pump mounted on the back side of this panel, as per the above ballast fix doc. In my case, the whole thing slides in there and is invisible. It doesn't take up any useable space. The weight of the battery helps offset some of my girth. (not all of it!) The wiring is as follows: one 8 gauge from the alternator (existing perko) One large 4 gauge ground to the starting battery ground on the engine block. A hot and ground 6 gauge from the new battery to the audio amp, fused behind this panel (60a)

One unique feature of this isolator is the remote LED function, you can troubleshoot the condition of your batteries by watching the state of the LED.  I mounted the LED in the panel, I'll have to look into the compartment to see it but that's not a big deal for the simplicity of having all the wiring in one place. Plus, it looks cool!

Here is the finished installed panel, no lost storage space!