Battery configuration

[feeez]

This is my first summer with our 2001 350 mariner. We have the standard configuration 2 batteries for house and engines and 1 for the genny. This configuration does not seem able to keep the fridge running at anchor. I have surmised that the battery protection kicks in and shuts the fridge down after which the batteries still have lots of umph to start the engines.
I would appreciate hearing what configurations other use: number of batteries, 6v vs. 12v etc. etc.

Thank you
Fraser

[Lyndon670]

Are your house batteries deep cycle? Simple fix is to increase the reserve capacity on the house batteries. You can also add more batteries to the house bank at the same time. I don't think you will have the space avail to switch them to 6V gofl cart syle batteries, but I would go to the biggest reserve capacity 12V batteries and add as many batteries (deep cycle) as I can space permitting.

[waybomb]

Seems odd. Have you checked all the connections between the batteries and the fridge? Why does the fridge run so much - are the gaskets in good shape?

Then again, I do not believe the two batteries would keep the frdige running all night long and still have the ability to start the engines. How about running the genset once in a while to charge things up?

[Lyndon670]

Also, what does "at anchor" mean? Sometimes I anchor for a week at at time. How many hours from start of discharge until full discharge or "safe" mode.

[feeez]

Also, what does "at anchor" mean? Sometimes I anchor for a week at at time. How many hours from start of discharge until full discharge or "safe" mode.

Lyndon,

Nice to hear from you again!!

We found out about this issue about 3am at anchor with water dripping out of the fridge.... not good

I did a test at the marina and found that the fridge will only run for about 2 hours before the battery protection on the fridge kicks in. From my research this happens at 10.4 volts. Assuming that the protection circuit is working properly then it seem that our batteries are in need of replacement and/or enhancement. I do have room in the engine compartment for more batteries so this will be a project for next season along with the addition of an inverter.

All good... we are having fun with our Carver

Rgds
Fraser

[Lyndon670]

Hey Faser! I didn't even check who was posting lol...good to hear you are enjoying the boat!

If your batteries are dropping that low, you may want to have them load tested. Either that are at the end of their life cycle OR they are not deep cycles. Also, before you add batteries - isolate the house bank from the starter. You only need 2 starting batteries for the mains, and 1 for the genny on a separate circuit. The house should only be house, and not for any heavy deep load.

My Silverton was wired that way, house batteries combined with starting batteries - it's the quick way to get the boat out of the factory but is completely wrong for power management.

Let me know how you make out. Where are you keeping the boat now?

[feeez]

That does sound like the better route to take. My Celebrity 280 that I traded in on the Carver was set up that way. One battery for each engine and the house was separate. I will keep you posted on the progress.

We are at Beacon Bay in Penetanguishine and have been living here waiting for a house to be built.

Best regards
Fraser

[After Taxes]

I am watching this thread with much interest, as a new Mariner owner.

I recently had a 320 Cruisers, in which I installed four TROJAN six-volt golf cart batteries, for the house, and successfully anchored or docked on islands without shore power for two weeks, with proper input from the onboard Kohler genny, and I took along a Honda 2000, since I already owned it, and it's so inexpensive to run for hours.

Needless to say, I kept the fabulous six-volts, but have not yet had a chance to review what's in the Carver - I only know there are two twelve-volt house batteries in parallel.

Interestingly, my first impression is that there seems to be less room in the Carver engine room for additional batteries, but I'll probably find a way by moving or adjusting the battery trays, if possible.

If you have room, and want to switch to six-volts, you will be most satisfied with the increase in amp hours. Four six-volts will beat two twelve-volts every day of the week. A little more expensive to set up, and you'll need some extra cables, but well worth the effort.

Here's a close up of two of my six-volts. I use the T-105.

And a link to Trojan for all the specs.

http://www.trojanbattery.com/product/t-105/

p.s. we boat The Bay annually, lurking around Beausoleil, not far from you, so perhaps we'll cross paths and can compare notes. Feel free to keep in touch over the next year, as I'll gladly share any knowledge I obtain with respect to good Mariner battery management.

[feeez]

I think there is plenty of room behind the engines for more batteries.... I like the 6 volt option as do my marina mates.

Hope to see you on the bay in 2015.... our boat is called Discovery.

Fraser

[timjet]

If you allowed your batteries to discharge to 10.4 volts you may have permanently damaged them. You don't generally want to allow any battery to discharge below 50% of full change which is about 12.2 to 12.3 volts.

Having 2 12v batteries comprise you're House bank and feeding a 12v refrigerator is not going to get you through the night. At least below the Mason Dixon line.posting.php?mode=reply&f=12&t=931#

I'm located in FL and in the summer my refrig uses about 250 amps per day. I generally use the generator to recharge the House bank twice a day. So to determine the House bank capacity without considering any other loads I need a minimum battery capacity of 250ah. Charging every 12 hours and not letting the bank go below 50% capacity.

In practice however my House bank capacity is 420ah which allows for other DC loads and some inefficiencies. I never allow my batteries to get below 70% of full charge before I recharge.
A battery monitor will allow you to determine your House bank state of charge (SOC) as a percentage of full charge. This makes it easy to determine when you need to charge your batteries. They are relatively cheap especially compared to the cost of a battery and easy to install.

Another consideration especially if space is tight, is to consider only one battery as your engine start battery. Very little energy is consumed to start your engines and that other engine start battery could be used to add capacity to your House bank. Just be aware that you shouldn't mix deep cycle and start batteries on the same bank. Carrying a good set of jumper cables will give you peace of mind.

Lastly, if you are going to anchor out a lot you need to have a battery charger that can bring your batteries up to at least 80% SOC within a reasonable amount of time. The original 30 amp 3 bank charger isn't going to handle a refrig operating 24/7 at anchor unless you want to run the generator 8-10 hours a day.