Can someone advise please...i have a victron solar 100/20 and a smartshunt installed on a 225ah battery which I know needs replacement. However I am noticing that when charging with solar the panel is providing 3amp whilst battery shows only an intake of around 1amp. This means I have a load of 2amp... however I have nothing on (just the mains) if I switch off mains the amps generated by the panel will equal that being absorbed by the battery. Any thoughts please?
Are you sure the solar isnt providing DC power to that item?
Charger should be off without shore power....am not sure if the boat has an inverter but don't think so. Another strange thing is that when I disconnected the solar panel this mysterious load decreased to 0.7amp and went up to 2 amp after I reconnected.... Then started floating, last I checked it was just 0.99 amp
You will need to disconnect everything from the shunt (load sidel and see what is happening there. If it reads Zero Amps then it may (and where i am thinking the issues is) be wiring related.
On another note, my bow thruster battery is connected with the house battery which is connected to the shunt...perhaps it is taking some load itself?
When installing shunts for metering batteries, you should have one shunt per battery (bank), and ensure that NOTHING ELSE is connected to the battery negative terminal other than the connection to the shunt. Otherwise, the shunt will not monitor other currents flowing from the battery, and can't do its job properly...
That missing current is probably your thruster battery.
Thanks. I only have the battery negative on battery side of shunt. When I said the thruster battery is connected with house battery I meant that there is a connection at the main switch of the house battery not a connection on the battery itself
So it is a normal thing? Would that stabilise over time?
The curious thing is that this missing current is approx 2.5amp with the solar panel connected and approx 1amp with panel disconnected. If the current is being taken by the thruster battery would this be explained because with the panel connected there would be more current flowing into the batteries?
Thanks!
On another note, I was given advice to remove the charge relay I currently have between house and thruster batteries and replace it with a victron dc to dc charger, so that I can remotely switch off the charge between batteries when I am on anchor. However, the relay I have at the moment shuts down the connection automatically when operating the thruster to protect the house battery from a heavy load. Will a dc to dc charger do the same automatically? Thanks
DC-DC chargers have on/off control of some kind so the mechanism that opens the relay when using the thruster could be connected to the DC-DC charger to shut it down. It would not happen automatically.
A relay will not provide any control over the direction of charge. The batteries are simply connected in parallel and energy will transfer from the battery with the highest voltage to the battery with the lowest voltage, until the two batteries are in balance.Relays are often used to link a starter and house battery so the alternator connected to the starter battery will also charge the house battery. The relay is only closed when the engine is running to insure the direction of charge is from starter to house battery. Vehicles are sometimes fitted with a "starter boost" switch which closes the relay so that the vehicle can be started when the starter battery that is too depleted to start the engine on it's own.
A DC-DC charger will allow transfer energy in only one direction (depending on the input/output connections) even with mixed chemistries (e.g., lead-acid charging lithium) and regardless of relative voltage of the two batteries. (There are also some bidirectional chargers but I believe there is still a way to control charge direction.) DC-DC chargers also limit charging current to the battery, especially important if the battery to be charged is lithium.
