Just installed a flexible solar panel and battery management system on my 309.
Results are really good the 120 watt panel keeps my 2 x 100 amp hr AGM house batteries fully charged all day and restores overnight loss by mid morning.
If anyone is interested I will post lots of pictures.
If I had a dime for every time I heard this I would be retired.
Unfortunately, in
most cases, for a cruising boat on the hook over night, this is
rarely the reality..
It is
almost physically impossible to restore overnight use by mid morning with a 120W panel unless you are a very, very, very light user of Ah's.
Another consideration is that most solar systems will trick Ah counting battery monitors, such as your Victron, into false resets to 100% SOC. However, this does not mean you are at 100% SOC just that the monitor is now incorrectly calibrated to your bank due to being
tricked by solar. This type of Ah counter DOED NOT reset on Ah's returned they reset on: time, voltage, current and time
at X current and time at X voltage. Solar has a nasty way of simulating fully charged parameters and resetting your battery monitor to 100% SOC even if you are only at 85% SOC......
I have had so many customers say that to me and then we fire up the engine and the batteries are taking 30A of charge current not the 2A - 4A or less, at 14.4V, that it should be to be considered
full, that these statements are
almost always incorrect and are usually caused by an incorrect understating of how Ah counters operate and reset..
All I am saying is to be
100% sure in what you are seeing because what is often assumed with solar & Ah counters, and what the reality is, are very, very often two entirely different things.
You
may be getting back what was used over night by mid morning but you would need to be a very, very light consumer of battery capacity to do so... Ah's out to Ah's in plus charge efficiency. Use 30Ah's put back put back 36 Ah's.
If you have not physically programmed out/off "Auto Sync" on your Victron I can say with 100% certainty that it is
wrong and you should not be trusting it for SOC....
With solar & wind there is only
one method for using an Ah counter correctly and that is to conduct
manual KNOWN FULL synchronizations.
How do you determine known full?
*Turn off all "loads"
*Fire up engine at 1500 RPM & absorption voltage
*Is the bank accepting less than 1.5% - 2% of its Ah capacity at 14.4V+ / ABSORPTION VOLTAGE? (14.1V for GEL)
*If yes, perform a manual reset....
*DO NOT do a
known full reset at float voltage.. The batteries need to be accepting less than 1.5% - 2% of Ah capacity at absorption voltage (14.4V for most AGM batteries except Odyssey). If charging at 14.8V such as Trojan known full at 2.5% or less is fine.