Battery problem

P

PhilR

Well-known member
Joined
Feb 3, 2011
Messages
416
Fluid Motion Model
C-28
Vessel Name
TUGALONG
We overnight on the hook one or two nights a week and lately, the house batteries have been down enough in the morning that the lights are dim, toilet won't flush, tv won't work, etc. If I run the generator and battery charger for about 5 minutes, it brings the charge back up....everything is fine. The major electric draw is the refrigerator, but little else other than a light or two for an hour or so. I'm surprised that an overnight will draw that batteries down so much, and that a few minutes on the charger will bring them back up so quickly. This is the 3rd year for these batteries...original equip. Are they due for replacement?

Phil
 
Phil,
My rule is to replace my flooded batteries every 3 years. I am always a bit overkill though. They can be purchased at Walmart for about $70.00 or so. As far as your problem goes, the batteries coming up on voltage after charge is not what is important, it is how long they hold the charge. First check your fluid in all the cells to be sure they are full. If they are not and you can see the plates are not covered, you may have and issue because you did not keep them topped off. When filling your cells use DISTILLED WATER ONLY. If your cells seem okay with the water level, check each cell with a hydrometer. A bad cell or two will drain the others of power. if you have a bad cell replace the battery. The next thing you can do is take out your batteries and bring them to any auto store that sells batteries and they can do a load test on the batteries. They need to be fully charged before you take them there. This test will determine what health your batteries are in and how they do with a load.
If you have a full bill of health on your batteries then you may have a parasitic leak from a piece of equipment. There are a succession of tests you will need to do to determine what may be causing your problem. I suspect though that you may just have a bad battery, so hopefully you won't have to start searching.
Let us know how you make out

Mike Rizzo
 
A couple thoughts: on our boat, the fridge is the main power user while at anchor. Second behind that is the anchor light. We switched the anchor light out for an LED, and that makes a difference. If it isn't steaming hot out (and we try to find places to wander where the weather is moderate), we will turn the fridge off at night. As long as the fridge door stays closed all night, it hasn't been a problem for us.

Not sure what kind of battery charger your boat has, but I can't imagine any charger being capable of bringing the batteries back up to a full charge in just five minutes. I would assume you are only getting a surface charge. Ours takes hours to get up to a full charge once the batteries are low (30 amp, 3-bank smart charger). This would lead me to suspect the batteries are not holding a charge. One bad cell in one battery can bring down an entire bank. Time to check 'em.

Marine batteries live a tough life. That's why most battery manufacturers only offer a 12 month warranty on flooded cell marine batteries, and up to 36 months on an equivalent car battery.

Best wishes,
Jim B.
 
Some thoughts on charging using the generator. During Desolation Sound this year, we spent several days at a time on the hook and or without shore power and some very cloudy days. I noticed that it was taking several hours with just the generator running to bring the charge back up on our batteries. Also that we were only bringing them up to around 13 volts. Turning the battery charger (ProMariner 40) on with the generator was much quicker and brought the batteries up to around 13.7 volts. Running the main engine was the fastest bringing the batteries up to 14.1 or 14.2. Checking the specs on the Mase 2.7 we find that its alternator for battery charging is only 12 amps. Our ProMariner 40 (replaced the original 20) is rated at 40 amps. And the main engine alternator is rated at 140 amps. So it makes sense that you will have to run the generator for several hours to bring the house batteries that are 50% discharged back up to 100%. With generator times at some of the parks limited to 2 hours in the morning and 2 hours in the evening, that by itself may not be enough time for a 12 amp alternator to complete the task. Adding your 20 amp (standard) battery charger may make the difference in charging rate. You may not be bringing your house batteries up to 100% charge with the generator alone.

I have not checked the specs on the Onan that the factory is installing in the new 31s, but I will bet that its alternator puts out much more than the Mase. The Mase is set up to provide 2.7 KW of AC power and its alternator is designed to just recharge its starting battery.

Herb
 
You can get a small load tester from most auto parts stores on a loan basis. We found that one of our house batteries was the culprit and after replacing it we have not had a problem. I do agree that after about three years of tough use, marine batteries are on borrowed time. That is not to say that five or six years cannot be achieved as some of my friends have done quite well. Perhaps they don't abuse them the way I do.

Pat & Carolyn, Ladybug, Too
 
The STELLA has just crossed back into the U.S. from Canada after we were part of the Desolation Sound trip. We are now at Roche Harbour and have now traveled 1080 miles (so far) on this fabulous trip after touring the Broughtons and turning around at Port McNeill. Will spend a few days in the islands and then head home to add more miles - south end of Lk Washington. Shhhhhh - we are already planning on 3 months for the Broughtons and north to Bella Bella next year!!

Anyway, this battery issue thing. This has been on my mind on this trip and maybe I can get an opinion here. I do check my batteries all the time and keep them clean and do all the good things you are supposed to do (had bass boats with electric motors so learned early about deep cycle batteries). Since we were on the hook a lot but usually able to get the batteries up to full specs each day (either with generator or main engine) I had no problems. My question is this - we have a pair of house batteries (a 2011 model 25SC) out of the 4 that runs the fridge and anchor light every night when on the hook. Would it be of any benefit to rotate the thruster batteries / starting battery with the 2 house batteries? Kind of like give the house batteries a break? I check the house batteries every morn on the Battery Bank readout and the thruster and engine batteries are always fully charged. It's the house batteries that take all the abuse - right?
 
You need to check your batteries. Sometimes the engine battery is a different type, although deep cycle they sometimes are made to give a lot of amps for starting the engine and then be able to rest and charge up for the next surge. The house batteries should also be deep cycle, but with the ability to give out a steady stream of power over a longer period. I actually connected my thruster to the house batteries with a switch between it and the house batteries. When I am on the hook I switch it to couple with the house and give me more amp hours. Then before pulling anchor I re-isolate the thruster battery. Long and short of it I think I would want to leave the battery for my engine starts alone so that it was never abused and used for the purpose intended.
 
Thank you all for your input. It sounds like I have a bad battery. When I get up to the boat later this week, I'll test my house batteries as suggested. My plan was to replace all batteries after 3 seasons In the interest of preventive maintainence. Hopefully I can get thru this season as I would prefer to install new batteries in the spring. Are the AGM batteries worth the extra expense? Will the factory charger work with the AGM batteries? Mike.... to parallel the house and thruster batteries, do you turn the parallel switch on and the engine battery switch off until you are ready to start the engine ?

Phil
 
knotflying, thanks for the response. I went back and checked my batteries. The thruster battery and house batteries are deep cycle group 27. The starting battery is not deep cycle which I missed the first time when I looked at them. But your idea to connect the thruster battery to your house batteries is a great idea which I will pursue after we get back from this trip.

Jim H
 
I won't repeat everyone's good comments. Just adding a few.

Consider adding a LINk10 or Linklite battery monitor. This measures A_Hrs in a nd A-Hrs out. In addition to whats suggested this a good way to see how your batteries are taking a charge or how they discharge over tme with loads.

On a Volvo D4 300 Alternator charge starts off at 50 A and tapers over time typical for a smart charger. The stock inverter/charger on the boat behaves the same way.

These two charging systems are essentially smart charging systems, over time the charge rate tapers, to the point where you are running the gen set for extra hrs but the charge now is only putting out 5 A per hr., not worth it.

checking water levels, checking each cel with a hydrometer and finally a load test are all worth while things as others have clearly stated.

Consider a clip-on DC ammeter (not just AC amps), a good one is expensive but one can be had for < 100$ at Sears. In this way you measure :Total charge rate on the entire house set and individually on each battery.

We were also on the Desolation sound cruise. Typically, running just the inside fridge and smalll portable Engel deep freeze, we were going through 60 A-Hrs in a 24 hr period. Note; the wine cooler was shut off plus the outside fridge was shut off. We have LED lights on the boat which also helps.

Back to 60 A-hrs per 24 period while at anchor. That basically means we are only good for three days continuous. house set is 400 A-Hrs. Batteries shouldn't be drawn down below about 50%.

As others have said, past 3 years, batteries are on a down hill slide.

If one battery is bad in the house set, the ENTIRE set must be replaced to avoid circulating currents.
 
PhilR":b1ge5dcz said:
Thank you all for your input. It sounds like I have a bad battery. When I get up to the boat later this week, I'll test my house batteries as suggested. My plan was to replace all batteries after 3 seasons In the interest of preventive maintainence. Hopefully I can get thru this season as I would prefer to install new batteries in the spring. Are the AGM batteries worth the extra expense? Will the factory charger work with the AGM batteries? Mike.... to parallel the house and thruster batteries, do you turn the parallel switch on and the engine battery switch off until you are ready to start the engine ?

Phil
Click to expand...
Phill,
Everybody has different preferences regarding battery type. AGM are great batteries, no maintenance, long lasting and they can be placed in any position, even upside down. However, if you do the math $275.00 V $70.00, you can buy 4 flooded for one AGM. At 3 years per change of a flooded you have about a 12 year break even period, Not sure what charger you have, but most have a selector switch (dip switch or a small dial) that you set the battery type. Because of this you really can't mix battery types. It is either all or none.
As far as adding the thruster to the house batteries; you don't use the parallel switch. The parallel switch should only be used if you engine battery won't crank the starter and you then use the other batteries to get it started. Similar to someone using booster cables.
What you need to do is run a positive cable to a new battery on/off switch and then from the switch to one of the positive terminals on the house batteries. A pretty easy installation. Make sure you use the large battery cable of the same size on your batteries.
 
I must be lucky I suppose. Here's WM's describing the mystery of batteries and their charging. http://www.westmarine.com/webapp/wc...reId=11151&page=Battery-Charging#.UhuFOBa9P4M

My factory stock flooded cell batteries are at their 4 year mark, and still chugging along without issues. I do check fluid levels and top up with distilled water as needed.

I do a load test periodically... fully charge them and then let them rest for 24 hrs with all devices on the boat requiring electricity turned off.

See http://www.tugnuts.com/viewtopic.php?f=5&t=3047&p=22273&hilit=battery#p22273 for more info.
 
I permanently merged the thruster and house banks into a single 3 battery bank. I also installed a Victron battery monitor to accurately measure charge state. Voltage readings alone are not accurate, particuarly under load. I used high current (Blue Sea 600A) bus bars and individual 1G cable from each battery to balance currents and reduce voltage drop during high current operation, such as when the thrusters or inverter are used. This has worked very well. See my detailed post for a description and pictures. viewtopic.php?f=5&t=3665

The group 27 marine deep cycle batteries most of use are not true deep cycle batteries but are better than starting batteries. For deep cycle performance 6V golf cart batteries are superior. These have thicker plates and handle many more deep cycles.

As already mentioned avoid discharging below 50% for best life. It is also important to periodically charge batteries to 100% to reduce plate sulfation. It takes a lot of time to get to 100%, charging is fast to about 80% capacity, after this the charge acceptance starts to drop and it takes a lot of time to get to 100%. So the practical range of use during for multiple days away from shore power or without prolonged cruising is 50% to 80%, or only about 30% of the total AH bank capacity. A smart 3 stage charger, properly configured for battery type, is required for fastest charging. The first stage is bulk, where the charger outputs its maximum capacity until the battery voltage reaches a preset point (14.5V or so) that depends on the battery type. Once this is reached the charger holds the voltage steady and the current starts to drop as the absorption stage starts. Once the current reaches a low threshold value the battery is considered fully charged and the charger switches to a lower float voltage. The better chargers also monitor battery temperature, charging voltages decrease as temperature increases. Note that the main engine alternator is not a 3 stage charger, it will charge at a lower voltage than a smart charger and takes a long time to fully charge. You can convert to a Balmar alternator with a smart regulator to have true 3 stage charging from the engine. The smart regulator monitors battery temperature to control charge voltages and alternator temperature to prevent overheating during prolonged high current charging.

The 12V output from a genset is low current (10A or so) and is intended to charge a dedicated genset starting battery. You need to switch on your AC powered charger when using the genset. The standard charger in my R27 is 20A, it would take a very long time to replace a significant discharge. For example, it would take over 4 hours to replace 80AH when you allow for charge efficiency of a battery. I have added auxiliary single output 45A 3 stage charger to reduce charge time. I selected this size so I could run the charger and water heater at the same time and stay within the maximum rating of the Mase 2.7. Contrary to what a lot of people think, this is NOT a 2.7KW genset. It is rated at 2.2KW maximum and 1.9KW continuous. The Mase 2.5 rating is identical. The maximum rating is for 30 minutes or so, this is long enough to heat the water. The 1500W water heater and 700W charger put me right at the maximum. Once the water heater is done I switch on the 20A charger to increase my battery charge current to 65A.

Head over to the Cruisers forum electrical section to see a lot of discussion about batteries and charging. Some long distance cruisers are converting to LiFePO4 (Lithium Iron Phosphate) batteries which can be repeatedly discharged to near 0% and rapidly charged back to near 100%. Newer smart chargers can be configured for this battery type.

Howard
 
HOWARD,
You brought up a point that I have been wondering about but not sure it can be done. I have a 25SC with 1 starting battery and 3 deep cycle battery. As you know 1 deep cycle is for the thruster and the other 2 are for cabin. My batteries are still good but when I change can I use two 6 volt batteries for the cabin?

Jim
 
Hi Jim,
On my friends RV his two hose batteries went bad in a year. :x I replaced his two 12v batteries with two 6v deep cycle batteries of the same frame size connected in series...It worked Well and lasted a long time 😀
I was thinking of doing the same thing on my boat when the time came.
 
Will two 6 volt deep cycle give you more amp hours than two 12 volt? I don't think so. From what I have read if you hook a battery up in series you get twice the voltage, but not twice the current. In parallel you get twice the current, but no gain in voltage. The Everstart battery has 115 amp hours so two hooked up in parallel will give you 230 amp hours. From what I see on the golf cart batteries by Duracell you get 215 amp hours, however in series the amp hours will not double. So, I think I get slightly more from 2-12 volt in parallel. Any battery gurus have a different understanding?
 
Two golf cart 6V connected in series will have about the same or slightly more AH than the two Group 27 in parallel. Golf cart batteries are about 220AH.

Howard
 
HRowland":2cpp7m4w said:
Once the water heater is done I switch on the 20A charger to increase my battery charge current to 65A.
Click to expand...

Howard: Can you simply connect two smart chargers to the same battery bank and get the combined total amperage to charge the batteries? I thought the smart chargers would get confused such that one would take over and the other would react to the takeover by reducing its output or some other unpredictable outcome. Your monitor must be telling you that the combined amperage is being used effectively, but I don't understand it. Can you explain?

Thanks for your exhaustive description - it's great!!

Doug
 
Doug,

During Bulk charging phase both chargers will output their maximum capacity. Once the voltage threshold for switching to absorption is reached, one or both will hold their output voltage constant and let the current taper as the battery bank continues to charge. Since two battery chargers are not the same, even if the same brand, one will switch to absorption before the other. This is not an issue, once absorption is started the charge current is determined by the battery internal resistance so one charger will likely provide the bulk of it. At the end of absorption the chargers switch to float, and again, it is very possible that one charger will provide more than another. Again, this is not an issue.
So bottom line, the chargers will not fight each other and will provide combined current during bulk charging. I can see this on my battery monitor, and actually see slightly higher than the combined outputs since the Mase genset is also contribuiting a few amps from its built in battery charger.
In my case I only use the auxiliary charger when I want to rapidly charge the house bank, such as while running the genset on the hook or a mooring. The multi output ProMariner charger is "smarter" so I use this as the only charger when hooked to shore power. The ProMariner has an additional capability, it will enter a standby mode during extended periods of low demand. This reduces the float voltage to a lower level and extends battery life.

Mike,
The primary advantage to golf cart batteries is overall cost. They have superior cycle life and will outlast the typcial 12V "deep cycle" batteries resulting in lower $ per AH delivered over the lifetime. If it was convenient to move the start battery I would consider changing my setup to use 4 golf cart batteries in series/parallel. However my current batteries are 2 1/2 years old and still working well, no reason to change them yet.

Howard
 
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