House battery questionsi

[Nancy & Hugo Shaw]

I need to replace my house batteries after four years on my 2014 R29. I don’t have a very good understanding of the electrical systems on my boat or good battery maintenance practices. To ensure I don’t repeat mistakes, I have a few questions that I hope some members from TugNuts can help me with:

1. What is the measure of a cycle. Is it the number of times you discharge the battery down to 50% of its capacity - or every time I pull on the batteries even if they are discharged just a small amount.

2. I have a Honda generator. When I am on the hook should I charge my house batteries up every day even if they are at say 80% of max or should I wait until the discharge down to 50% and then run the generator.

3. Does my engine alternator change both my starter battery as well as my house batteries. I was told by a service rep that the engine alternator only charges the starter battery unless you have some sort of sensor/splitter that detects when the house batteries are also low and then directs some of the engine alternator to the house batteries. How is the 2014 R29 set up. Does the engine alternator charge both the starter as well as the house batteries. Is the thruster battery recharged by the engine alternator?

4. Same service rep said a standard one panel solar panel only puts out about 30 amp hours per day and that is barely enough to service the load of the refrigerator on the boat. Is that correct for the R29 - that I should only count on getting 30 amp hours per day from the solar panel and it will just cover the refrigerator load.

5. It was also strongly recommended I install a battery monitor so I can accurately measure amp-hours remaining in my house batteries and the load I am using. Do members recommend I install a battery monitor.

6. Related to my question about battery cycles. I was told to expect about 450 cycles from a good set of AGM 31 house batteries. But I have also heard house batteries will only last about 4 years. That seems too short. If I do not discharge my batteries below 50% of max I should get more than 4 years of service life. We boat about 200 to 250 hours per year. Keep our boat at a marina and hooked up to shore power. We will be on the hook for 1 to 2 days at a location - sometimes stretching to four days. How many years of service life should we expect from our house batteries if they are treated well?

7.Last question. Last week we were out and our house batteries discharged down to less than 9.5. When we started up the boat our GPS would not work (we used a back up app on our IPad to get home) and over a four hour trip our house batteries would not take a charge. When we got back to the marina and hooked up to shore power the house batteries charged up - but I expect they will only hold the charge for a short time. My question - when my house batteries get very low do they reach a point where the engine alternator will not recharge them. And without house batteries I did not realize my GPS shuts down even while underway


Thanks for any feedback and advise. I need to become a more responsible battery owner.

Hugo

 

[knotflying]

I need to replace my house batteries after four years on my 2014 R29. I don’t have a very good understanding of the electrical systems on my boat or good battery maintenance practices. To ensure I don’t repeat mistakes, I have a few questions that I hope some members from TugNuts can help me with:

1. What is the measure of a cycle. Is it the number of times you discharge the battery down to 50% of its capacity - or every time I pull on the batteries even if they are discharged just a small amount.
Even a small discharge can be detrimental because sulfites can harden on the plates. The sooner you recharge after a discharge the better for the battery life

2. I have a Honda generator. When I am on the hook should I charge my house batteries up every day even if they are at say 80% of max or should I wait until the discharge down to 50% and then run the generator.
A proper charge never hurts, As I stated the longer a discharge the worse for battery life

3. Does my engine alternator change both my starter battery as well as my house batteries. I was told by a service rep that the engine alternator only charges the starter battery unless you have some sort of sensor/splitter that detects when the house batteries are also low and then directs some of the engine alternator to the house batteries. How is the 2014 R29 set up. Does the engine alternator charge both the starter as well as the house batteries. Is the thruster battery recharged by the engine alternator?
We have charge relays on our boats. This allows the alternator to charge all the batteries at any given time. There is a safeguard that will not allow charging to a group if the voltage falls below a certain level

4. Same service rep said a standard one panel solar panel only puts out about 30 amp hours per day and that is barely enough to service the load of the refrigerator on the boat. Is that correct for the R29 - that I should only count on getting 30 amp hours per day from the solar panel and it will just cover the refrigerator load.
This is correct. Depending on amount of sun and length of time with sun the panel charge will most likely not keep up. However I can get at least 2 days before I feel like I need a charge

5. It was also strongly recommended I install a battery monitor so I can accurately measure amp-hours remaining in my house batteries and the load I am using. Do members recommend I install a battery monitor.
This is a matter of opinion and I am sure I will get kickback on this one. My feeling in certain cases is less is more. You should do a calculation on how many amps you will be using and that will tell you what to expect from your battery capacity. I monitor my voltage level and know that every morning after a night on the hook I am usually at 12.42 volts. If that changes then I know I have to look for the culprit or perhaps my batteries are loosing capacity

6. Related to my question about battery cycles. I was told to expect about 450 cycles from a good set of AGM 31 house batteries. But I have also heard house batteries will only last about 4 years. That seems too short. If I do not discharge my batteries below 50% of max I should get more than 4 years of service life. We boat about 200 to 250 hours per year. Keep our boat at a marina and hooked up to shore power. We will be on the hook for 1 to 2 days at a location - sometimes stretching to four days. How many years of service life should we expect from our house batteries if they are treated well?
Way too many variables in the equation. The 29 access to the batteries can be difficult hence no maintenace or AGM is preferred. Unfortunately many things can happen unintentionally over time and even AGM batteries can get ruined. This is why I prefer flooded and I replace them every three years regardless of condition, a very inexpensive alternative to AGM. There is a product sold to fill the battery cells remotely and easily which would eliminate the need for AGM. This will also be a topic with feedback. 😀

7.Last question. Last week we were out and our house batteries discharged down to less than 9.5. When we started up the boat our GPS would not work (we used a back up app on our IPad to get home) and over a four hour trip our house batteries would not take a charge. When we got back to the marina and hooked up to shore power the house batteries charged up - but I expect they will only hold the charge for a short time. My question - when my house batteries get very low do they reach a point where the engine alternator will not recharge them. And without house batteries I did not realize my GPS shuts down even while underway
The answer is as stated above. The alternator charges the engine battery. Then there are relays that will open and close to allow charging of the house and thruster. If a particular group goes below (I thing 10 volts) the relay will not allow charge because it suspects there is something wrong with the battery. The house and engine can be connected manually with the parallel switch. This is usually done because of a reverse problem, the engine battery went dead and you can supplement it with the house. If after starting the engine you could have turned the parallel switch on and the house batteries would have received a charge. And yes, the chartplotter is powered by the house.


Thanks for any feedback and advise. I need to become a more responsible battery owner.

Hugo

 

[BB marine]

7) when the batteries are low the isolation relay has to have voltage rise to activate the relay. This is done by stating engine and then switching the cross over switch to on . Leave it on for a few minutes and the isolation relay will close and the alternator will begin to charge the house battery as it normally does. Remember to turn cross over switch off after the relay is activated. If you don’t the house battery is connected to cranking battery and you may discharge the cranking when engine is not running.
3) Yes engine alternator does charge house and thruster batteries. The reason it didn’t your last trip was explained in (7)

The rest of the questions I don’t have fact answers for. I keep my batteries charged to the higher % as much as possible. I don’t full cycle the batteries. My experience o f marine batteries is 3 years anything after that is good but I proactively change the batteries after three full seasons of use. Maybe over kill but I don’t like battery issues. I use wet maintenance free. Group 27.

 

[Nancy & Hugo Shaw]

Thanks Knotflying and Brian for the info. Nice and clear and I will put it to good use.

The internal temperature sensor on my sun panel controller also broke on my past trip - looks like that is a sealed unit and I need to replace it. Saw on-line the unit was about $200.

 

[knotflying]

Before you commit to buying AGM you may want to consider sealed wet, that Brian uses.This will avoid the topping off issue and they are considerably less. However, if changing battery type you should have them all the same.

As far as your Morningstar goes. Are you sure it is the internal temperature sensor? If the terminals for the remote sensor connections get wet it causes continuity and then the unit thinks it has a remote sensor. When it dries out and continuity ceases you will get an error code. You can do a reset by a) remove fuses on lead from controller to batteries, b) disconnect hot lead from solar to controller. This wire is live protect it from grounding! c) wait a minute and reconnect lead from solar to controller. d) reinsert fuses to battery leads from controller to batteries. See what happens.

 

[Automaticman865]

Hi, also if you change from agm to flooded or flooded to agm don't forget to change the settings on both the charge controller and the battery charger.

Stuart

 

[Cutwater28GG]

Great post by Knotflying!

I find observing some data as you use the boat will improve your understanding the system and would recommend a meter.

Xantrex amp hour meter with a shunt is good option. I have the Balmar smartguage which is pretty good and does not require a shunt.

 

[Nancy & Hugo Shaw]

Thanks for the feedback

What is a shunt for the battery monitor?

 

[Cutwater28GG]

see the wiring diagram on this page
https://www.google.com/url?sa=i&sou...aw3Y7JHcXrogKU5RyV1Fi7kf&ust=1533010837764043

 

[knotflying]

Great post by Knotflying!

I find observing some data as you use the boat will improve your understanding the system and would recommend a meter.

Xantrex amp hour meter with a shunt is good option. I have the Balmar smartguage which is pretty good and does not require a shunt.

Yes, the Balmar is a great unit and as I said, many of the bells and whistles are a matter of personal preference. There is no right or wrong answer.

 

[chronicity]

Thanks for the feedback
What is a shunt for the battery monitor?

A shunt is used to measure amps flowing into or out of the battery.

It is a small-value resistor that is connected so that the battery current has to go through it. When current is flowing, there is a voltage difference between the two sides of the shunt. The voltage difference is proportional to the amount of current. The monitor measures the voltage difference (in volts) as an indication of current (amps).