Reviews
Redarc Battery Isolator
A dual battery system is pretty much a must have for living in a van. If you want regular power available on demand you will need to have at least one of those big deep cycle batteries. The easiest way to charge up one of those batteries is via a dual battery system that charges from the vehicle's alternator. The alternator will be able to produce so much more power than a solar panel. Once you have your second battery charged, you will not want to discharge your starting battery so I recommend that you use an automated battery isolator.
I brought a Redarc smart start dual battery isolator off of eBay, however I recommend that if you buy one that you by direct from Redarc or from Super Cheap Auto who have a nice kit that is essentially a pre-wired Redarc isolator. All you need to do is attach the leads to your battery terminals. This is much easier than wiring it all up yourself as shown in my guide.
Testing.
The model I have is the SBI12. As can see from my guide to installing it, I have had it wired in permanently between my solar charged batteries and my starting battery. It sits there quietly and does an excellent job of charging the starting battery after the solar charged house batteries are charged. The house batteries in the bus are charged first because I use power from them the most. This is the reverse of most charging arrangements, in most cases the starting battery charges first then the secondary battery. In my case, as the van sits without driving for quite some time and has five solar panels on the roof it makes sense to charge up the driving battery off of the solar panels when there is excess voltage left over.
Testing of this device has basically been its in use service. When I first installed it the house batteries were almost fully charged. The device regularly switches over current to the starting battery from the house batteries as the sun hits the solar panels. When I run my 12 volt fridge which drains the house batteries a bit it takes longer for the isolator to switch in as it takes a bit longer for the main batteries to charge up to 13.5 volts, the switch over current level. However I tend to hear the reassuring clunk as the solenoid switches over about an hour and a half after sun up. The end result is that the starting battery is always charged when I want to start the bus.
The system is a fuss free way of operating a dual battery system. Once installed it soon settled down and runs completely without maintenance. The only problem with it is the running temperature which is about 70 degrees Celsius. Too hot to handle. This is a concern considering how close I have had to mount the isolator to batteries. Despite the heat, the device is safe to use, as even at 70 degrees, this is too low to ignite pretty much anything. It has melted off some insulating tape before I installed a cooling fan over it though. I can't wait to get my hands on one of the newer models brought out in March of 2007 that runs cooler.
Opinion.
Definitely worth having. A great Australian made product. A real world beater. Easy to use, easy to install if you buy it with the wiring kit and very low maintence. I reccomend buying one of the new low temprature ones though.
