Hello everyone,
In a campervan with Victron components (Orion XS, SmartSolar MPPT, Blue Smart IP22 Charger, Smart Battery Sense in VE.Smart Networking), the starter battery (PB) is to be charged by the solar system, which is connected to the leisure battery (LiFePO4).
The standby chargers available on the market either require the solar charge controller or charging booster to be replaced, and/or are rather inflexible and expensive. Unfortunately, I couldn’t find a suitable solution from Victron, although I think there is likely to be a frequent need for one.
I would like to present the following very cost-effective solution here and ask the community about alternative solution concepts. Perhaps there are even better ideas.
The starter battery is also charged via the load output of the SmartSolar MPPT (On = 13.8–14.6 V), using two 10 A silicon diodes and a PTC fuse (3 A) for current limiting. This provides a maintenance charging voltage of approximately 13.0 V. The load output is programmed to become active only when the leisure battery is being charged, and it can be freely adjusted.
The Orion XS (conventional alternator) also remains switched off at approximately 13.0 V (it starts at 13.5 V).
The above mechanism should also work when charging via the Blue Smart IP22 Charger.
This should cover all operating conditions.
Ideally, this function would be integrated directly into the Victron charging boosters.
For the sake of clarity, I have largely omitted other components, including fuses and the battery isolator switch.
The solution is currently undergoing testing.


