House batteries

L

Len

Active member
Joined
Apr 27, 2016
Messages
35
Fluid Motion Model
C-28
Vessel Name
Honu Makai
We've had our R27 (Honu Makai) for almost 8 mo.s now and lately I've had a problem with my house batteries draining quickly while moored. Engine battery stays charged, no problem. The boat is a 2012. Do the house batteries usually need replacing faster or should I be looking for an electrical issue? I can charge on shore power, unplug and leave, and a few days later the batteries are low again. Planning on getting new ones but thought I'd throw the question out there.

Thanks, Len
 
Why don't you disconnect the battery and put an ammeter in between to see what the load is when all is off. From that you determine if you have a high parasitic load or the battery just don't hold charges. Also check fluids if they are such chemistry and see if the charger is properly set up for your chemistry. At the end if all checks out, your batteries may have been mistreated at some time and just don't hold a charge. With a proper charger some batteries can be rejuvenated.
 
Along with what the previous post suggested, I would do the following in this order.

If they are standard flooded batteries check water level before charging up. If they need water use only distilled water. Charge up the batteries to full capacity. Let them rest a couple of hours. Get a hydrometer and check the specific gravity of each cell and make sure they are all okay. One bad cell will drain a bank. If the batteries are AGM or maintenance free skip the distilled water part. Now take the batteries out and have a load test done at one of the auto stores. Or if you have the proper equipment do your own load test. If that passes, then:
Start looking for a parasitic load that is draining the batteries. There are devices that stay on all the time such as the co detector and propane leak detector, radio memory etc, but they are a minimal draw. Be sure all your breakers are off and nothing is on. Now place an ammeter in series to see how much draw you are getting. If it is more than the usual items that stay on you have to start searching for the culprit. This can be a long tedious search so hopefully the issue, although more costly, is bad batteries.
 
Great information, thank you very much!
 
In my experience, the batteries need to be replaced every 3-4 years. It is what you should expect, unless you've bought some high-end batteries in order to squeeze out another year or two. To me, buying the high-end batteries just isn't cost effective. Luckily, my two house, one starter, and one thruster batteries don't all die simultaneously, so their replacement is staggered. I replace both house batteries simultaneously. My thruster battery is being replaced this spring for just this reason.

You may be able squeeze another year or two out of them, but a quicker discharge than expected is a good indicator that the batteries are going, as long as your electrical systems are operating normally and batteries are topped off.
 
At this age I would just replace. You have done well and the cost of a couple of new batteries is way less than the cost in time to try and find if there is a problem which there likely isn't. I bought replacement agm's of the same model from Amazon delivered and it solved my starting issues for my 2012 cutwater 28
 
You did not mention what battery type you have. AGM batteries can take some abuse and should last longer. Have you ever accidentally fully discharged your batteries? That can really shorten their life. As discussed on another thread,before you go out buying batteries, I would charge them up and then have them load tested. If they are bad, replace them. If they are good, start looking for a parasitic drain. It would be a shame to buy new batteries and then discocer the issue was really related to something else.
 
sorry I read 8 mo's as years!
yes clearly something else going on.
 
re: house batteries :

i was disappointed to find that my top of the line expensive AGM 'lifeline' house batteries bought new in 2012 lasted only 4 years and were only as long - lived as much less expensive brands. the symptoms of their demise was that even after being charged to full 100 % capacity, within 2 days of cruising they were down to 12.5v with minimal 12v equipment running , mainly nav lights, freshwater pump and interior lights... :cry:
 
Kaisardog":25eki7jg said:
re: house batteries :

i was disappointed to find that my top of the line expensive AGM 'lifeline' house batteries bought new in 2012 lasted only 4 years and were only as long - lived as much less expensive brands. the symptoms of their demise was that even after being charged to full 100 % capacity, within 2 days of cruising they were down to 12.5v with minimal 12v equipment running , mainly nav lights, freshwater pump and interior lights... :cry:
Click to expand...

Many factors affect the life of a battery. Climate, usage, sulfation, water loss, lack of charging, complete drain and lack of use to name a few. Sealed AGM batteries typically last longer. They are not "open to the air" by way of a vent tube. They do not lose water. They are also packed tighter. Plates do not vibrate causing material to shed from the plates and short out. Or worse yet, simply breaking apart in some high vibration applications. Sealed AGM batteries typically last 3 to 5 years on average. 6 to 8 years is easily obtainable with proper maintenance. Typically sealed AGM batteries will give warning before completely dying. They will start slower, and require more charging. This is your clue to replace the battery. Typically they do not fail all of a sudden. Conventional "acid-filled" batteries have a harder life, for many of the reasons listed above. Conventional batteries typically only last 2 to 3 years on average. Although, 4 to 5 years is possible, in the best environments, and with excellent maintenance.....
 
As a quick check, without an ammeter on hand, simply get everything to a nice state of charge and then disconnect the batteries completely. Watch the voltages for a couple days and see what happens. If they hold the charge then start looking for the parasitic loads (with an ammeter). If one or more don't hold the charge there is likely something going on inside the battery.

If one house battery holds charge and the other doesn't that really seals the deal. Bad battery.
 
A good clamp meter is essential for reading amps on a line.
 
Kaisardog":33dewopt said:
re: house batteries :

i was disappointed to find that my top of the line expensive AGM 'lifeline' house batteries bought new in 2012 lasted only 4 years and were only as long - lived as much less expensive brands. the symptoms of their demise was that even after being charged to full 100 % capacity, within 2 days of cruising they were down to 12.5v with minimal 12v equipment running , mainly nav lights, freshwater pump and interior lights... :cry:
Click to expand...

Can you be more specific with regard to two days of cruising? Were you on the hook for two days without the engine running? If so your numbers are not that bad. You mention nav lights, water pump etc. No refrigerator or wine cooler? They are big power hogs. I have always been a proponent of flooded. There are too many things that can kill batteries, even if they are AGM. The cost V benefit of AGM has not been convincing for me. I care and respect my flooded batteries and replace them every three years, regardless of condition. It is still cheaper than a good run with AGM.
 
Yes, you need a dc amp meter. They alway seem to cost more than the standard ac amp meter. In Canada mine was 150 dollars. I am also paranoid about loosing current. First thing I did was check each line from the batteries following the lines back to each device. Recording the current as I went. Then turned on devices to see how much the draw was with each. I recorded in a spreadsheet, estimated the total time each day the device would be on and totalled for the day. That gave me the estimated amp hours used each day. Next take the total amp hours for all house batteries and divide by two to get the total available amp hours for your house bank. Divide the daily useage into this number to get the number of days you can go before you run your engine. My usage is very low. All lights are led and the only consumer is the fridge at 2.2 amps when running and the vhf and stereo. I have three AGM house batteries at 66 amp hours each. Total 190 amp hours /2 is 95 amp hours. That would last me about three days. I installed a solar panel, 75 watts, to charge at anchor. The clamp meter show I get 2.5 to 3 amps out of it in bright sun. I figure this makes up for the fridge. So I can stay on the hook almost indefinitely. In reality we move every three to four days.
So do the same for your boat, to get a handle on the power consumption, just like you monitor the fuel you have to monitor the electrical fuel. You don't need expensive mounted monitors. You will always need a clamp meter to test for problems when they occur.
A friend had a problem with the batteries going dead in a day. Traced to a bad device leaking power to ground.
 
Reed model C201 , maybe discontinued
They have a replacement R5030
Or fluke 325
They also are good to measure the alternator output, at different engine rpm!
 
Well, hats off to Pilotnavigator. I guess I am showing my age. When I was a kid just a few short years ago, clamp on meters would only give you AC amps. Now I see that they can also do DC amps. I did some reading and the DC ammeters measure the Hall effect which is pretty small but now the instruments are so much better that it works. I tried to dig into my Engineering texts from 50 years ago, got part way into it and said,"I wonder what Wikipedia says?"

Very cool, now I've got to get one.
Thanks
Rich

PS: My son who is a Master Electrician was equally surprised to learn this. Of course, he works pretty much with AC.
 
Glad I could shed some light on the subject. There are so many electrical problems that one of these meter will solve.
 
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