Dual batteries?

[Furstin]

+1 for the dc power meter, its something you can reset by disconnecting (at night) and over a few different weather scenarios will see what you actually get in. Other option is most decent regs have a head unit that will monitor all that.
Certainly wack the power meter in fridge side to see what that actually uses too.

I have the head unit but no aggregation data on outgoing power - there are some affordable options on ebay etc for this that can wire into a shunt. On the last keeler the solar was connected to bus bar ahead of shut at house batts to reader showed both unbound and outbound, but I think I can just do the maths with this one.

All in one on last boat and this built in one both draw about 4-5amps (in this weather, fan might ramp up if its 35deg?) - but without some data gather ive no idea how long it runs.

[Sail4life]

Thanks zebedee.

Just returned from our trip. With the 300w panels and twin 105a/hr batteries running everything from lights to fridge and Nav gear, we did very well. Through the battery switch, I was able to charge or draw power from with or both batteries. At night I shut the fridge off and turned back on in the morning.

The fridge wasn’t cycling (running full time) so need to investigate this as an issue, but the upshot was that the plates froze and held the temperature for ages. Insulation is excellent.

We never really ran out of power at all and had cold drinks and frozen veges for the week.
We did discover a thermostat control but not sure it is working properly. Like I said, more investigation needed, but the fridge performance was impressive.

Total cost of 2x 105a/hr deep cycle batteries and new battery switch was $580.

Darren

[Furstin]

Its that whole thing of 'everything's running fine till its not'. More than a few times Ive been looking at 13v until the sun goes down and then its 12.3v - oops!

Knowing whats gone out and in - for about $50, is money well spent to protect the $580 investment. https://www.ebay.com.au/itm/29466159021 ... SwOgdhxYVc

re: the runtime, if the plate of frozen and its turning off, its probably expected. Getting the thermostat right takes some playing - I usually run it hard in the afternoon sun or if I run the donk, then back it off overnight.

[impulse]

Using volts alone to estimate state of charge is just guesswork, you can't go past a decent power in and power out meter and ideally SOC as well.