B2B or Solar Controller

[The Simpsons]

We currently have a Viewstar solar charge controller VS1024BN for the hab battery but nothing to keep the vehicle battery topped up. I have seen adverts for dual battery controller but would this be better over a B2B system? Any advice would be gratefully received TIA.

 

[68c]

If all you want to do is keep your starter battery topped up you need a battery master. This device allows current flow from the leisure battery to the starter battery, it does not allow it to flow in the other direction. A fairly simple device with a large diode and current control to limit the transfer to a trickle charge. Available from Vanbitz with Motorhome Fun discount or even cheaper from Votronic or chinese versions from Ebay. Suggest get a cheap one first, upgrade if it does not do as you want.
The B2B works the other way, transferring current from the starter battery to the leisure battery, the system only does this when the engine is running so the starter battery is kept topped up by the alternator.
Getting a dual controller will work but only when using solar, on EHU there is unlikely to be any transfer unless you have a special expensive controller.

 

[addoaddo]

A B2B is to charge the hab battery from the engine when the engine is running at a descent level.

What you need to keep the vehicle battery topped up is a battery master. A battery master monitors the voltage on the hab battery (in solar) and connects the vehicle battery when it goes above a certain level.

A B2B works slightly differently which is explained in the cost. The B2B monitors the vehicle battery and when this is charging from the alternator it converts the voltage to hab battery to enable fast charging. It also "fools" a smart alternator to provide more power. (this is a simple description to explain the point)

 

[The Simpsons]

Thanks for your advice folks much appreciated

 

[68c]

You are most welcome.