Before and after fitting Victron remote sensor to leisure batteries.

[Jev88]

Purely for anyone's interest but feel free to comment. The vehicle is parked up and nothing turned on apart from alarm (that I am aware of so far as still learning the new to me RV).

Picture 1 - Victron Smartsolar record over a few days recently.
Picture 2 - Victron Smartsolar record over last three days after fitting Victron remote sensor and Bluetooth link to Smartsolar unit.

Anyone tell me why the difference in bulk/float etc time periods? The Smartsolar is approximately 5 or 6 metres away from leisure batteries box and is inside vehicle as opposed to "almost outside" battery tray.

 

[Raul]

From first look I can spot you got some voltage drop from controller to battery. After fitting the batt sense, the charger compensates for the voltage drop, and raises the voltage on the charger, until the set voltage reaches the battery. It seems you are loosing quite a bit on self discharge or very inefficient charging circuit connections. Could be that, not all that power makes it to the battery. The charger replaces pretty much the same amount of energy, before, and after the batt sense.
What batteries do you have?

 

[Jev88]

Brand new Numax 110ah (x3). I am expecting some voltage drop as batteries are at a guess 6+ metres from the solar controller (may well be more as I haven't fully inspected the cable route under the vehicle yet). (Replacing the wires from solar controller to batteries is on my to-do list as they look not far off domestic flex cabling wires to me). I haven't yet managed to work out all the wiring to the leisure batteries but have tidied it up a lot and put positives to one battery and negatives to the other end of the battery bay.
RV's have some sort of interconnect that can "call upon" the leisure batteries using a button "emergency start" on dashboard but I hear no relay click anywhere if i try pressing it. I did wonder what would happen if that relay was locked ON? But my guess would be a very fast drain of leisure batteries and reduced lifespan if they were assisting starting all the time - the old batteries were at least 4 years old (could be 12+ years old as we can't speak to the original owner, we are owner number 3 and previous owner never touched the leisure batteries). Just to confuse matters RV's often have an equivalent of the Battery Master system to trickle to engine battery. I have confirmed that leisure battery voltage jumps up when engine running (thanks to read out from Smart Solar).

 

[Raul]

It kind of makes sense, the alarm, probably undersized wires, maintaining the starter, etc. , all in 300wh daily ish is about right. I do believe if you improve on wiring from controller to battery, you will see a improvement in charging. At the moment the charger compensates for about 0,2v drop witch at every 10ah is 2wh loss. Not a lot, but it mounts up. And it’s just wasted heat trough the cable and connections.