dual refrigerator 12V power draw....

[CliffA]

i will be installing a new AC/DC powered cockpit refrigerator soon and the cabin AC/DC powered refrigerator is working fine....we have not been on extended cruises with the 340 yet so i don't have any experience with battery draw yet...i have 4 deep cycle group 27 batteries on the boat....i am not 100% sure but i think one battery is dedicated to the genny, one battery is dedicated to the starboard engine, and two batteries in parallel for the house battery and port engine....

will the alternators on the engines be able to keep all the batteries fully charged while cruising when both refrigerators are running and other misc. things like the stereo and GPS also running?....

if we decide to drop anchor for a while (or maybe camp overnight) and later need to replinish the battery charge is it better to simply run the engines and let the alternators charge the batteries or should i start the genny and let it charge the batteries?.....i understand that running the engines will require buning more fuel than running the genny but which method will recharge the batteries the fastest?....

assuming a fully charged state in the late evening, should the two batteries in parallel have enough reserve power to run both refrigerators overnight as well as running other items such as a few lights and the stereo/TV for a few hours and still be able to start the port engine the next day?.....

i thought about running a test of the battery draw while docked at the marina just to get a feel about how long the batteries will last under different circumstances before we actually go on an extended cruise and/or stay on the hook overnight.....

any insight from those with a similar battery set-up is appreciated...

cliff

 

[Do Over]

Just run the genny when your anchored...that's what you have it for....during the summer my genny runs from the time I leave the dock to when I come back...regardless of how long I'm out.

clif

 

[GJarrett]

Cliff, I don't know how comparable my experience will be for you, but our little AC/DC frig along with fans, stereo, etc in our 240DA will run down a single group 27 battery overnight. I would think two larger units would do the same thing to two parallel group 27s. FYI, one group 31 deep cell will carry our load, but I still have 2 of them in parallel just for ease of mind. I have enough juice to start the engine on them even after 18 hrs on the hook. You might consider upgrading to parallel group 31s on your house bank.

 

[CliffA]

Cliff, I don't know how comparable my experience will be for you, but our little AC/DC frig along with fans, stereo, etc in our 240DA will run down a single group 27 battery overnight. I would think two larger units would do the same thing to two parallel group 27s. FYI, one group 31 deep cell will carry our load, but I still have 2 of them in parallel just for ease of mind. I have enough juice to start the engine on them even after 18 hrs on the hook. You might consider upgrading to parallel group 31s on your house bank.

thanks....after spending some time on the boat this past WE we are still evaluating if we really want/need a frig in the cockpit....a cooler with ice and beverages fits easily in the space under the cockpit galley so we are thinking about that as well....

if we do go with a frig i think your idea of updating the parallel batteries to group 31 is a good one....

cliff

 

[JimFromMD]

i will be installing a new AC/DC powered cockpit refrigerator soon and the cabin AC/DC powered refrigerator is working fine....we have not been on extended cruises with the 340 yet so i don't have any experience with battery draw yet...i have 4 deep cycle group 27 batteries on the boat....i am not 100% sure but i think one battery is dedicated to the genny, one battery is dedicated to the starboard engine, and two batteries in parallel for the house battery and port engine....

will the alternators on the engines be able to keep all the batteries fully charged while cruising when both refrigerators are running and other misc. things like the stereo and GPS also running?....

if we decide to drop anchor for a while (or maybe camp overnight) and later need to replinish the battery charge is it better to simply run the engines and let the alternators charge the batteries or should i start the genny and let it charge the batteries?.....i understand that running the engines will require buning more fuel than running the genny but which method will recharge the batteries the fastest?....

assuming a fully charged state in the late evening, should the two batteries in parallel have enough reserve power to run both refrigerators overnight as well as running other items such as a few lights and the stereo/TV for a few hours and still be able to start the port engine the next day?.....

i thought about running a test of the battery draw while docked at the marina just to get a feel about how long the batteries will last under different circumstances before we actually go on an extended cruise and/or stay on the hook overnight.....

any insight from those with a similar battery set-up is appreciated...

cliff

Hey Cliff,
I spend a lot of time on the hook and do not like to run the generator over night. I have the cabin fridge and cockpit fridge configuration like you do. Typically I leave the pier with a full charge and have the refrigerators on from the time I leave until I get back. I also keep a cooler in the cockpit for drinks/ice, and leave the food in the fridges. I initially started out with 4 group 27 batteries (2 banks in parallel). In my setup (factory setup) there is no dedicated generator battery. I did not have trouble running out of power. I did have trouble with my battery charger which seemed to boil my wet cell batteries. I upgraded the entire setup to 4 group 31 agm batteries and a new 40 amp (vs original 30 amp) charger. The bump up in charger amperage was based on guidance from the promariner techs, to aid in quicker replenishment while on the generator.

I typically leave the refrigerators on about 3/4 max cooling level during the day, and bump it down to a lower (warmer setting) at night. It's always still cool enough to keep food safe but just runs less at night when it's cooler than the day time anyway. I also use 2 12v fans during the day and over night, as well as the cabin/cockpit stereo. My standard procedure is to run the generator for a few hours before bunking down for the night, which allows the cabin to cool down and AC to take the humidity out, put a little extra juice in the batteries, make some hot water for showers etc. Then in the morning I'll run the generator for an hour or two while making coffee, microwave/stove, add some juice to the batteries, hot water, dishes etc. I've never run out of power (both on the old 27s, or new 31s). If you think you are running low, just run the generator and charger. There's also an argument about excessive wear on the alternators while idling to charge substantially depleted batteries. I'll let someone else chime in about that, because I'm no expert. Just reporting what I've seen.

I did convert my TV to a 12v TV (vs the factory 110v) so it would run without the generator. Also converted most of my cabin and cockpit lights to LED for lower power draw and less heat.

As a side note, I like that it's quiet without the generator on. I also thought it burned a lot of fuel, until I looked in the manual. Have to look again for the actual number, but the Kohler 5E doesn't burn that much even under a big load.

 

[CliffA]

Hey Cliff,
I spend a lot of time on the hook and do not like to run the generator over night. I have the cabin fridge and cockpit fridge configuration like you do. Typically I leave the pier with a full charge and have the refrigerators on from the time I leave until I get back. I also keep a cooler in the cockpit for drinks/ice, and leave the food in the fridges. I initially started out with 4 group 27 batteries (2 banks in parallel). In my setup (factory setup) there is no dedicated generator battery. I did not have trouble running out of power. I did have trouble with my battery charger which seemed to boil my wet cell batteries. I upgraded the entire setup to 4 group 31 agm batteries and a new 40 amp (vs original 30 amp) charger. The bump up in charger amperage was based on guidance from the promariner techs, to aid in quicker replenishment while on the generator.

I typically leave the refrigerators on about 3/4 max cooling level during the day, and bump it down to a lower (warmer setting) at night. It's always still cool enough to keep food safe but just runs less at night when it's cooler than the day time anyway. I also use 2 12v fans during the day and over night, as well as the cabin/cockpit stereo. My standard procedure is to run the generator for a few hours before bunking down for the night, which allows the cabin to cool down and AC to take the humidity out, put a little extra juice in the batteries, make some hot water for showers etc. Then in the morning I'll run the generator for an hour or two while making coffee, microwave/stove, add some juice to the batteries, hot water, dishes etc. I've never run out of power (both on the old 27s, or new 31s). If you think you are running low, just run the generator and charger. There's also an argument about excessive wear on the alternators while idling to charge substantially depleted batteries. I'll let someone else chime in about that, because I'm no expert. Just reporting what I've seen.

I did convert my TV to a 12v TV (vs the factory 110v) so it would run without the generator. Also converted most of my cabin and cockpit lights to LED for lower power draw and less heat.

As a side note, I like that it's quiet without the generator on. I also thought it burned a lot of fuel, until I looked in the manual. Have to look again for the actual number, but the Kohler 5E doesn't burn that much even under a big load.

thanks for the detailed reply Jim....that info is very useful....

cliff

 

[Shock_Loaded]

Cliff, It will vary according to what you have on, ambient temp, etc. Run the genny when you need to, its really that simple. It won't burn 1 gallon/hr at full load.
Where you docking this year? Boat rack?
J

 

[CliffA]

Cliff, It will vary according to what you have on, ambient temp, etc. Run the genny when you need to, its really that simple. It won't burn 1 gallon/hr at full load.
Where you docking this year? Boat rack?
J

well hello there Jason....good to hear from you...its been a while since i read any post from you...

yep, we are at the Boat Rack Marina....slip B29.....are you still there also?...stop by some time...

cliff

 

[islandhopper00]

Hello Cliff. Like Gerald, I have 2 group 31 Optima agm batteries in parallel for house bank. 1 group 27 agm Optima for dedicated starting on my 240. I have way more reserve than I need, but It's nice to not have to think about power at anchor. I run my fridge, fans, stereo, lights, tv, and anchor light all night and can still start the engine the next morning. My starting battery never gets used.
The beauty of agm batteries is the recharge rate is faster because internal resistance is low. Most trips, the batteries get recharged by the main motor when I run to different places.

 

[Shock_Loaded]

well hello there Jason....good to hear from you...its been a while since i read any post from you...

yep, we are at the Boat Rack Marina....slip B29.....are you still there also?...stop by some time...

cliff

Been busy Cliff, no time for the boat. Looking forward to a good boating season tho. New boat looks nice! I will stop by and see you. I'm on C dock... Text me when you are at the lake.
Jason

 

[CliffA]

Thanks for the info Mike...

Jason i am sure i will see you at the marina soon....glad you are finding time again to spend on the boat...

cliff