Refrigeration and battery life while on shore power

[davisr]

I recently replaced my Yeti cooler with an Engel fridge. I love the Yeti, but I hate dealing with the ice and the ice-melt issue. Moreover, as others have suggested, I hate having to stop at a convenience store to pick up a bee r, only to have it become luke-warm by the time I get to the boat. Sure is nice now, stopping by after work, drinking a cold one in the cockpit, watching the world go by. The Engel is both AC and DC. It automatically switches over to DC whenever you remove the shore power connection. Soon after I had installed the new wiring for this Engel, I realized that it would probably not be a good idea to leave the DC plug in the receptacle after I left the boat. Why? Because if, for some reason, the AC power went out or the AC breaker tripped, then the Engel would automatically switch over to DC and, in a matter of days, would kill the house bank. I raised this issue recently on another forum, but no one addressed it. http://www.cruisersforum.com/forums/f14/engel-fridge-and-iota-iq4-battery-charger-155964.html

I always leave the boat plugged into shore power, and I always leave the Engel plugged into AC. I've been working under the assumption that the galvanic isolator I installed some time ago protects my boat. Hopefully, my assumption has been correct.

Roscoe

 

[BigEasy]

Thanks for the advice on the low voltage cutoff device. I ordered the Blue Sea unit today. Already damaged my AGM bank once when I forgot to turn the charger back on after a day sail resulting in the fridge draining the house bank below 50%. Those batteries are too expensive to ruin. The cutoff unit was $55 on Amazon including free shipping.

 

[seadaddler]

I leave ref on 24/7 and was told it is not good shutting off the ref every week end or after being out for a few weeks,I have solar panels to keep batteries fully charged 24/7 and don't leave inverter /charger on and been doing this over 10 years.
Nick

 

[Pat]

I know very little about pros and cons of this, but I do know that we had a Catalina 30 catch fire some years ago at our club which was caused by an overheated refrigerator trying to stay cool down below on a 100 degree day...the entire galley was destroyed but our PM saw the smoke and was able to access the boat and put the fire out before the entire slip went up in
smoke. Our club is about 7 miles from the nearest fire department so we now discourage 24 hour a day use of AC or Refrig's.
unless the owner is present.

 

[Blitz]

By the way, Sailor's Solutions has had a Low Voltage Monitor for years:

http://sailorssolutions.com/?page=ProductDetails&Item=LVA01

I'm not affiliated with them at all, but have had good service from them in the past.

 

[JamesG161]

am getting one of those too. Other than the high drain from the 12VDC refrigerator, I won't worry about the Inv/Charger being the last/first line of battery defense. Little need for long recharge with the LVD installed.

https://www.bluesea.com/products/7635/m-LVD_Low_Voltage_Disconnect

I was about to push the button to order the LVD and decided to pull down my breaker panel to see where to install and stupid discover the refrig and water heater were both 120VAC. Both switch had an Hunter switch protector to prevent accidental ON's.
The refrigerator pulls 9 Amps from the Freedom Inverter/Charger, which is the battery drain with loss of genset/shore power.

@Maine Sail I have heard of a cutoff for 120VAC using 12VDC as the signal to switch. Do you know of such a device?
Jim...

 

[Maine Sail]

I was about to push the button to order the LVD and decided to pull down my breaker panel to see where to install and stupid discover the refrig and water heater were both 120VAC. Both switch had an Hunter switch protector to prevent accidental ON's.
The refrigerator pulls 9 Amps from the Freedom Inverter/Charger, which is the battery drain with loss of genset/shore power.

@Maine Sail I have heard of a cutoff for 120VAC using 12VDC as the signal to switch. Do you know of such a device?
Jim...

This is simple...

You turn the invert mode OFF unless you actually want or need to invert. No need for anything fancy just don't allow it to auto-transfer...

When off of shore power physically turn invert mode OFF. Now when you plug into shore power the inverter will only act as a charger. If shore power is lost it should not auto-invert if the invert light on the remote is off.

Leaving any inverter charger in auto-transfer is really a bad habit to get into. Even when not inverting the standby draw can be in excess of 1A or 24 + Ah's each day you sit there and do nothing with the inverter.

 

[druid]

I've always kept my fridge running on "low" so I don't have to buy/bring condiments, etc. every time I go out. And cold beer is appreciated... My new Nova-Kool fridge HAS a low-voltage cutout (settable to two different voltages), but it only draws 2.5 Amps when it's on (less than 50% of the time), so it pretty much can be run by the solar panel if the shore-power gets kicked out.

As for battery torture: when I was living aboard I started with a cheapo Canadian-Tire charger, and it never kept the batteries charged with the fridge, etc. on (that fridge drew 5-6 Amps). But when I changed to a Xantrex Smart Charger, everything worked fine - I was getting 7 years life from the batteries. So I would say you're fine as long as you're using a smart charger to keep the batteries up.

druid

 

[JamesG161]

This is simple...

You turn the invert mode OFF unless you actually want or need to invert. No need for anything fancy just don't allow it to auto-transfer...

@Maine Sail

You da man!

The only thing I every need to invert, when not aboard, is a few rechargeable devices and I can always do that using a spare small portable inverter with my on board Jump Start, since they pull about .000001 amps, .

You saved me about $250 and no new remote switch mount. Now the Admiral will have to jot down another electrical check when leaving the boat.

But when I changed to a Xantrex Smart Charger, everything worked fine

I have the older Name Xantrex --- Freedom® 2000. My 9 amp at 120VDC Grunert Frig/Freezer is a luxury and a power hog. When a nearby lightening strike knocked out shore power my IC, saved my batteries with a cut off at 11 VDC. I also unplugged shore power for a Ag/AgCl probe test and forgot the Refrig switch.

BTW I had that Blue Seas LVD in my Amazon shopping cart at $75 for about 6 days now. That item showed up on every web page I used. The price is now in my cart for $68 and free shipping. Lesson learned with Amazon!
Thanks again,
Jim...