could inverter be only using starter battery and not my house bank?

[EvilRabbit]

Electrics noob here.

Our fridge/freezer seems to only stay cold when on shore power. Suspect an issue with the inventor/battery bank as no issue when on shore.

House bank is full, but starter battery for genset is dropping - could the inverter be draining from starter only?

[cal40john]

Any mistake or crazy idea from PBO is possible, only way to find out is to start tracing wires.

How much current does the fridge draw? What percentage of the time? How big is the genset battery? How quickly is the battery being drawn down? The numbers for what would be normally sized for the above items would probably kill the battery in less than a day. And being a starter battery it wouldn't take many cycles before the battery was no good anymore.

[Sailmonkey]

Any crazy thing is possible.

What sort of fridge? Is it even connected to the inverter?

[rwidman]

Originally Posted by EvilRabbit

Electrics noob here.

Our fridge/freezer seems to only stay cold when on shore power. Suspect an issue with the inventor/battery bank as no issue when on shore.

House bank is full, but starter battery for genset is dropping - could the inverter be draining from starter only?

1) Is your refrigerator an AC/DC refrigerator or a 120 volt refrigerator that relies on an inverter for power away from the dock?

2) I can't trace your inverter wiring from where I sit. Disconnect the starting battery and see if the inverter still works. If it does, it's drawing power from your house battery.

There are several ways to wire a boat including several wrong ways so it might pay to have a marine electrician actually visit your boat and determine how it is wired and what, if any improvements can be made.

[FionaJC]

Run your inverter. Disconnect starter battery. If the inverter stops the answer is yes,

[Dave22q]

Sounds like your AC refrigerator is getting insufficient power. The first thing to check is the inverter. Does it have sufficient power and does it appear to be working ok. Many small inverters have indicator lights for insufficient input power. After ruling out the inverter then disconnect the starter battery as suggested.
Do the refrigerator compressor run constantly when you hook up the AC power? That would be another indication of insufficient power.

[FionaJC]

I find our inverter 1000W runs our domestic fridge no problem but when I start it at night it drains the battery just getting down to temperature. I now start it on a colder setting with a genny and make sure all batteries are charged and the fridge is down to temp. I then increase the temp setting, switch to inverter and it just cuts in and out topping up the "coldness". When motoring the engine keeps the mains power flowing into the starter and domestic batteries via a VSR and Adverc and 85Amp alternator. We have 1 x 65Ah start 2 x 110Ah domestic with a 110Ah emergency fully charged. 200W of Solar, 2.0 Kw Genny and no shore power except when we pull in at a marina for a weekend stop over. Lighting will be all LED by May. Boat in use March to November East Coast UK.

[EvilRabbit]

Thanks for all replies, problem is the electrical guys are off till next week. Will disconnect the starter batteries and check. Should have ample power and inventor is a big Victron Quattro.

[baycruiser]

Originally Posted by EvilRabbit

Electrics noob here.

Our fridge/freezer seems to only stay cold when on shore power. Suspect an issue with the inventor/battery bank as no issue when on shore.

House bank is full, but starter battery for genset is dropping - could the inverter be draining from starter only?

common issues I think it is imperative to know your own boat and its wiring so DONT get someone else to fix it unless they give you explanation and you understand but the wiring must be big enuf as short as possible and real good connections now asuming you need your inverter for your fridge and the wiring is direct from battery to inverter SHORT AND BIG use a temporary wire if necassary ie battery jumper leads now isolate starter battery is fridge working properly? Get simple multimeter and learn basic functions dc and voltage!! before you connect check volts and polarity plus and negative (house battery and start should be 12.6/12.8 sometimes more if connected to some charger).Remember your inverter will give a kick when connected only capacitor usually unless polarity is wrong all good inverters are protected from reverse polarity damage but all inverters use power when on standby good to know how much yours uses If wires are bad for whatever reason replace and reroute for simplicity and directness again keep it simple and DONT listen to too many people and learn everything you can about your own boat

[EvilRabbit]

Updating old posts: turns out the gauge of wire was too small for the run from bank to fridge.