System and Isolator

(jaubrey) · (jaubrey) **Join Date: Feb 2003** 10-17-2005, 4:16 PM

We are thinking about replacing the factory sub in the X30 and thinking about some new sub. We're thinking about throwing a couple of blue tops in as well and I was wondering about an isolator. Is it hard to setup and worth the time? Any pics?

(kraig) · (kraig) **Join Date: Dec 2002** 10-17-2005, 7:33 PM

Very worth the time and money!! But be careful, some isolators draw amperage. The best on the market, one I use along with alot of people on here who will contest they are the best, is the Hellroaring. Go to http://www.hellroaring.com for more info and to order. They are very helpful for help. Easy to install too. Alot of us on here can help you out with the installation. It's an automatic Isolator/Combiner. It senses charging from the alternator and brings your back up battery online, then takes it offline when there is no charging from the alternator i.e. when you kill the engine. If you do go this route, get the optional remote switch for the unit. It allows you to monitor the isolator/combiner, take it offline all the time or combine it all the time. It's something I monitor alot with the remote module. They are expensive, but well worth it! I love mine and wouldn't run with out it.

(pickle311) · (pickle311) **Join Date: Oct 2005** 10-18-2005, 5:39 AM

dude, that's way too much money for a heatsink with a couple of diodes mounted to it. I made one of those for less than $20, the heatsink was $15. Look on ebay, you can pick one up for less than $40 that's just as good, but you won't get the monitoring capeability.

(rodmcinnis) · (rodmcinnis) **Join Date: Sep 2002** 10-18-2005, 11:36 AM

The Hellroaring device is a lot more than a couple of diodes.

In the conventional, cheap isolator you end up with a loss of voltage of one diode drop, which is typically 0.7 volts. This is a loss between your alternator and the battery, which makes a BIG difference in the charge rate to the battery.

The battery combiners sense the voltage and use transistors to connect the two systems together when it is appropriate to do so. The voltage drop for low currents is negligable. For higher currents it is important to size the combiner properly (which is a function of the maximum alternator current).

Another issue is that a "one wire" alternator may not work at all with a cheap isolator. They shouldn't have any problems with a combiner.

All in all, a cominer is easier to install and has far fewer drawbacks than the isolator. They just cost more.