Solar Power and British Built Motorhomes : Simpler wiring?

[aandncaravan]

Today we worked on a older Swift Motorhome where Solar Power had been fitted. Not unusual, but this vehicle had the usual under bonnet split charge relay, for charging the habitation battery, replaced with a Victron Cyrix-I voltage sensitive relay.

 

This Victron unit is bi-directional in that in monitors BOTH Starter and Habitation batteries for a rise in voltage above 13.2v and connects them together. It allegedly does it intelligently.

 

So if the Solar Panel starts generating charge to the habitation battery, after a set time period, the Victron will connect in the Starter battery so it also gets charged.

 

Obviously if the Alternator starts charging the Starter battery, the Victron Cyrix-I will bring in the habitation battery in the normal way.

In other words if either the Habitation or Starter battery receive a charge, both batteries become joined together.

 

It does have limitations but might be a simpler way of getting Solar power from the Habitation battery to the Starter battery without using a 'Battery Master' style device?.

We suggest it will work the most effectively if both batteries are the same technology.

 

It could also be used in those Swift group vehicles that don't have intelligent charging systems, like the BCA system that don't always charge the Starter battery when on EHU?

These either don't have a facility to charge the Starter Battery when on EHU, or it needs to be selected manually. Replacing the standard split charge relay with one of these might be a neat solution?

 

Because most Continental built Motorhomes have the Split Charger incorporated into the main power distribution unit these may not be a good idea on German, Italian, Dutch, etc built vehicles?

 

Never fitted one, but seemed to work well enough on this Swift.

 

 

Technical spec :

Victron Energy Cyrix-i Battery Isolator Combiner Kit.

This Battery Combiner Kit is for adding a 2nd or 3rd battery system in your car, boat, RV or whatever you wish. It utilizes the simplest and most advanced technology to keep all your batteries charged using the engine’s electrical system, but isolates the starting battery when charging ceases so you never get stranded. The Cyrix-i 12/24-120 is a bidirectional voltage sensitive relay. It will therefore also engage if for example the accessory battery is being charged by a battery charger. Intelligent battery monitoring prevents cycling. The software of the Cyrix does more than simply connect and disconnect based on battery voltage and with a fixed time delay. The Cyrix looks at the general trend (voltage increasing or decreasing) and reverses a previous action only if the trend has reversed during a certain period of time. The time delay depends on the voltage deviation from the trend.

 

 

Available from the Battery Megastore Tewksbury.

 

https://www.victronenergy.com/battery-isolators-and-combiners/cyrix-battery-combiner-kit