Battery charger priorities

[rpmerrill]

I seem to remember seeing something on this a while ago. If it is a total re-run please let me know.

Ok, the boat (2012 R-27) is out on the hard waiting for spring under the shrink wrap.
During the winter lay-up the only battery charging it gets is from the attenuated solar charger which has worked great for the past five winters.

I have three chargers on the boat:
1.) The engine alternator,
2.) the shore power charger and
3.) the solar panel.

I am wondering where that charge is usually directed? Do they all go to the same place? It’s not shown on the wiring diagram I’m pretty sure the engine battery is charged by the alternator. From the engine battery there are two ACR’s feeding over to the Thruster battery and to the bank of 2 House batteries. Of course, the ACR’s are two way devices so they can feed back to the engine battery as well.

I am sitting here wondering where the solar charge is going: engine, house or thruster?

Some background to my question
Shortly after the boat was hauled out, I noticed that the engine battery was flat at about 6 volts. Not surprised… it and the thruster battery are over 5 years old. (I replaced the 2 house batteries last spring.)

Luckily, I am still close to shore power connection. I plugged in and charged the batteries for a bit over 24 hours. When I returned they were all at a pretty good voltage. I unplugged and let them sit for a day. The engine battery dropped to 10 volts, then next day to 8 volts then next day to 6 volts. Suspecting a possible unknown amp draw (I was unable to measure one) so then I charged up again and disconnected the NEG cable. Same result a couple days later.

One thing… when messing with the battery cables I noticed that the top of the battery was hot when charging AND when discharging over the next couple days. I took notes, but they are on the boat right now. I think charging was at about 100 degrees. and discharging was about 50-60 degrees in a 40 degree ambient. My only conclusion is that there is an internal fault that is killing the charge. Time for some new batteries. I’m thinking that the engine battery might have been on it’s last legs all this summer. We had no long trips or extended times off the shore power.

OK, with the engine battery NEG disconnected, it is out of the loop. And this is the reason for my questions.
1.) Where is the solar charge supposed to go?
2.) Will my remaining batteries receive any solar charge during the next couple months?
3.) Does the solar charger output go directly to the battery compartment or does it go to the hot side of one of the battery switches? (All the wires are bundled together and it is hard to tell without tearing into the bundles.)
4.) Does anyone recommend methods, such as jumper cables, to redirect the, <1 amp, charging current to the remaining (house) batteries.

Thanks

 

[Red Raven]

I agree your start battery likely needs to be replaced.

Regarding solar charging (assuming it is the factory Morningstar SunSaver duo solar system)
1) the solar controller should be connected to the house as battery #1 and start battery as #2. I know of some instances where this was swapped (including mine). If swapped, they should be swapped back to give priority to the house.
2) your remaining batteries should be charged from solar as before unless their negatives were also removed. If your house lights work it’s all good.
3) the solar charge goes directly to the battery terminal or through an intermediate buss or post. It does not go through the house battery switch. However, There is an inline fuse (likely in the battery compartment), that should be checked.
4) a jumper should not be necessary per all the above. If a jumper were actually needed you could just turn the parallel/combine switch on.

As always, you should verify the house is getting a charge by checking the house battery voltage. A current meter can also be used to measure the actual current going to the house from the solar charger.

Curt

 

[rpmerrill]

Uh, no, I have a Blue Sky Energy, Solar Boost 3024i controller.
It is a single "channel" only. There is an AUX output, but as I recall those terminals are empty. I'll check.

If the charger is feeding the house batteries only, at least they will be nicely maintained thru the winter. On the wiring diagram I have, the two ACR's are fed by the house battery. The only connection between the house and the thruster is thru the two ACR's with the engine in between. The house feeds excess charge to the engine and then the engine feeds excess to the thruster. With the engine battery gone, I doubt if the ACR's will do it. If I find that the house stays nicely charged and the thruster drops off this winter, that should answer my question.

I'm going to replace the engine and thruster batteries together. I was (stupidly) thinking that I could replace them once I get the boat down to eye level in the water. But, now that I think about it, I'll need the engine as soon as they drop me into the water. Maybe the parallel switch would save the day? Hoisting those 70 pounders up and through the shrinkwrap hatch is no fun. If I can wait until spring, I'll have the shrinkwrap off and the job will be a bit easier.

I'll take my ammeter down next time we have a sunny day. Maybe I can prove to myself where the charger is pushing the solar amps. It was indicating about 0.2 amps on it's display panel today. Might be hard to find, but it is good wintertime boating fun.

 

[GaylesFaerie]

My 2012 R27 was modified by combining the House and Thruster batteries into a single House bank and the 4th is my engine battery connected with an ACR to the 3 House batteries. I installed Solar this fall with instructions from the previous owner who is quite electrically skilled. The Solar panel positive wires into a Fuse close to the Solar Controller which then feeds into the Solar controller. The Solar controller Positive then feeds into a Fuse near the Battery Bank Positive bus bar and then into the Bus bar. That way the Solar will charge both the House bank and the engine battery to keep them topped off over the winter. So far it has been working like a charm. I've been down to the boat on multiple occasions since coming out of the water for winter to do some work including using the Inverter to power a small vacuum cleaner and making hot meals in the Microwave all with temps ranging from 35-55 degrees F. The Victron Battery monitor shows 100% SoC.

And if I understand correctly all sources of battery charge should be connected unswitched to the batteries. See the diagram below from Pacific Yacht Systems:

https://photos.app.goo.gl/TdXdVGXKW8zNEJNz5

 

[Red Raven]

rpmerrill,

If the after market solar charger is connected to the house and the house ground is still good the house batteries should be getting charge regardless the start battery negative connection state. The parallel switch will likely get you started in the spring but I would not chance it without at least a test. I recommend changing out the start and thruster batteries now but as a minimum, confirm you can try to start the engine on the hard (With parallel switch or new start battery). Of course, it would require a water source which you can feed into the lid of the sea strainer if available.

Curt

 

[rpmerrill]

Under the heading of "Every Day is an IQ Test" I have some info to share and maybe some more questions.

I really appreciate the gift of an "audience" that is interested AND I am forced to organize my thoughts in order to explain what I am thinking/exploring. Keep the comments coming.

I went to the boat today. A dismal dark day. The solar amperage was zero. However, I was able to check the output voltage.
12.4 volts. The thruster battery measured 12.28 volts and the house was at 12.4 volts. This is leading me to believe that the solar is hooked up to the house bank. When the sun shines I will check it again. It should be more apparent what the connections are.

I was able to trace the solar output wire. It loops around and goes thru a circuit breaker and then goes up to the battery switch grouping. Parallel, Thruster, House, Engine (left to right) Once there it disappears behind the Parallel switch angled towards the Thruster. BUT I can't see it and confirm where it actually goes. The switched are very tightly grouped next to each other and several wires, big and small, are back there. I attempted to dismount the Parallel switch from the panel but It would not budge. A lot of close coupled, big-damn wires would not let it budge. I can only assume that the solar hot goes to one of the battery switch terminals upstream of the switch. As mentioned above, a sunny day might help us figure it out.

I am still wonder if the two ACR's in series would ever work. That is a House battery pushing amps through two ACR's all the way over to the Thruster battery. A simple small wire jumper from the House to the Thruster might just solve it.

More exploration
As we all know there needs to be a number of "constant hot" lines from the batteries. On my boat there are several bundles of individually fused wires coming out from the bottom of the battery switches.

The Thruster Switch has 5
Bilge 1, Bilge 2 and Bilge alarm
Volt meter and CHARGER #3

The House Switch has 2
Volt meter 2 and CHARGER #2

The Engine Switch has 2
Volt meter 1 and CHARGER #1

Those CHARGER wires caught my attention. Over to the Stbd side compartment, the ProNautica 1220.
This charger has 3 outputs So there we go. An answer. The shore power charges each battery bank individually.
I also discovered that the ProNautica has a single temperature sensor wire. The manual recommends attaching it to the House bank, but mine was attached to the engine bank. I think because the wire wasn't long enough to reach.

So I will continue to do some more digging.
1.) Gotta find out where the solar amps are going?
2.) I'm even more curious how the Parallel switch works and what it "parallels" to the engine: House, Thruster or both?
Still having fun.

Oh, I almost forgot. Good Idea, Yes, I can start the engine out on the hard. I do that when I winterize pouring A/F into the strainer. 30 seconds of run time while pouring water or A/F won't even come close to an overheat situation. As long as I keep the water pump impeller wet I'm ok. Thanks all.

 

[Red Raven]

Under the heading of "Every Day is an IQ Test" I have some info to share and maybe some more questions.
....
I am still wonder if the two ACR's in series would ever work. That is a House battery pushing amps through two ACR's all the way over to the Thruster battery. A simple small wire jumper from the House to the Thruster might just solve it.
...

The two ACR’s will work. When active (connected) they form a direct connection across the two main terminals. When both are active it is a the same as a wire from the house bank to the thruster battery.

If you add a jumper, of the appropriate size, from the house bank to the thruster batt it will make them permanently combined into one combined bank. Thruster and/or house current will deplete the combined bank and all charging systems will charge the combined bank as one. You will no longer have separate batter banks. Just make sure that is what you really want and you understand the implications.

Curt

 

[rpmerrill]

Thanks Curt.

I'm not thinking of a permanent jumper, just a temporary one to keep the Thruster battery temporarily healthy until I go into the water this spring. So much easier to install new batteries with the boat down near eye level. I tested it a jumper yesterday and measured about 0.2 amps. The House and Thruster banks were only different by a tenth of a volt or so. With clear weather in the forecast this week I expect the House voltage to rise a bit and I'll try a jumper again to see what happens. Maybe I'll be able to see the ACR's will kick in. (Gotta re-read the ACR specs.)

Once they drop me in the water it is about a 200 ft cruise over to my slip. If the Thruster battery stays healthy until then, getting to the slip is easy.

The solar charger only puts out about half an amp from under the shrink wrap so I'm not too worried about high amps in a jumper. Suppose a small fuse might make it safe in case the Thruster battery decides to take a dump.

Again, it is always reassuring to have someone to proof read my logic.
Thanks

 

[knotflying]

Under the heading of "Every Day is an IQ Test" I have some info to share and maybe some more questions.

I really appreciate the gift of an "audience" that is interested AND I am forced to organize my thoughts in order to explain what I am thinking/exploring. Keep the comments coming.

I went to the boat today. A dismal dark day. The solar amperage was zero. However, I was able to check the output voltage.
12.4 volts. The thruster battery measured 12.28 volts and the house was at 12.4 volts. This is leading me to believe that the solar is hooked up to the house bank. When the sun shines I will check it again. It should be more apparent what the connections are.

I was able to trace the solar output wire. It loops around and goes thru a circuit breaker and then goes up to the battery switch grouping. Parallel, Thruster, House, Engine (left to right) Once there it disappears behind the Parallel switch angled towards the Thruster. BUT I can't see it and confirm where it actually goes. The switched are very tightly grouped next to each other and several wires, big and small, are back there. I attempted to dismount the Parallel switch from the panel but It would not budge. A lot of close coupled, big-damn wires would not let it budge. I can only assume that the solar hot goes to one of the battery switch terminals upstream of the switch. As mentioned above, a sunny day might help us figure it out.
.

Did I miss something here? If you are getting a charge from the solar panel, why are your battery voltages so low? Also, you do not mention a solar panel controller being connected anywhere, the solar panel should go directly to the controller and then to the batteries.

 

[BB marine]

I went to the boat today. A dismal dark day. The solar amperage was zero. However, I was able to check the output voltage.
12.4 volts. The thruster battery measured 12.28 volts and the house was at 12.4 volts. This is leading me to believe that the solar is hooked up to the house bank. When the sun shines I will check it again. It should be more apparent what the connections are.

Your battery voltages are low and I would not rely on the solar to top them off. When storing the boat for the winter a full charge should be applied. You want the battery voltages to be 12.7 from start of storage. A good battery or battery bank should maintain a charge for several months. Your house bank is sitting at 75% and your thruster is sitting at 50%. If you have a 120V receptacle in the area of the boat I would plug the boat in for a few hours to get the batteries up to 100% charge.( if you do this isolate the engine battery by disconnecting the battery terminals from the battery. For safety isolate (protect the terminal end so it can not ground out) the battery cable from the ACR to engine battery and the ProMariner charger lead. You do not want a bad battery to be in the charging circuit when using the ACR's.

I am still wonder if the two ACR's in series would ever work. That is a House battery pushing amps through two ACR's all the way over to the Thruster battery. A simple small wire jumper from the House to the Thruster might just solve it.

It will work with no problem but the battery voltage must first reach 13.0 V for more than 90 sec. With the batteries House bank sitting at 12.4 V it will take several hours with a solar charging at 7amps.

Those CHARGER wires caught my attention. Over to the Stbd side compartment, the ProNautica 1220.
This charger has 3 outputs So there we go. An answer. The shore power charges each battery bank individually.
I also discovered that the ProNautica has a single temperature sensor wire. The manual recommends attaching it to the House bank, but mine was attached to the engine bank. I think because the wire wasn't long enough to reach.

The charger will charge each battery individually until one battery bank reaches 13.0V at that time the ACR's will close and now all batteries as long as they have a voltage higher than 10V (9.5V is spec) This is good as long as you have good batteries in all banks.If you do have a bad battery in one bank the charger could over charge the good batteries.

You are correct about the sensor wire. It should be attached to the house bank. The fact that it was attached to your engine battery and your engine battery appears to have a bad cell and would get hot. This would turn the charger off until the battery cooled which would effect the charging of the house and thruster batteries.

Once they drop me in the water it is about a 200 ft cruise over to my slip. If the Thruster battery stays healthy until then, getting to the slip is easy.

You have an engine battery that seems to be more of the issue. I assume you are planning on using the parallel switch for this. Once you start the engine and it starts a charging output. The alternator will have 30% to 50% output at 1500rpm 150 amp (alternator is rated higher but I'm being realistic) so 45 amps to 75 amps. In a short time the ACR's will close (13.0V) and the thruster battery will start to accept a charge. All the batteries should be parallel as long as they do not fall below 12.75V. Put the boat in the water take it out for a shake down cruise for half hour your thruster battery will have enough reserve to get you in the slip.

 

[rpmerrill]

More good advice and info.
I opened up the ACR website and discovered the 13 volt criteria for opening. We are a long way from there.

And yes, I had noticed the 12.4 on my house bank was unusually low. I recorded some of these voltages a few weeks ago. I will double check the log next trip to the marina. It has been pretty dark and overcast this past week. No solar probably for a while. I am also wondering if the shrink wrap is extra opaque this year. Gotta check that.

Good news is that I am only about 10 feet from a 30 amp outlet. I can put the charger on for a couple days to see what happens (with the NEG) disconnected from the Engine battery. With the Engine battery our of the loop, the boat charger should work better (no hi temp issues) I also have a BatteryTender (for my antique little car) that I could hook up instead of the Promariner to prove the function of the ACR's.

Stay tuned.
Rich
PS: It could be that the good batteries are in the low state of charge because they spent some time trying to supplement the failing Engine battery until it got below the threshhold and the ACR's shut down.

 

[rpmerrill]

Update:

I think I discovered why my solar contribution was so low. Besides the dreary weather....

I had put my "radar" mast down but the shrink wrap guy erected a tall 2x4 mast anyway for the shrink wrap. And my boat faces south. I made a couple observations over the past couple days. Except for early in the AM and late in the PM, I don't think the solar panel is generating much of a load at all.

I had pretty much determined that the solar charge was going to the house batteries. But with diminished expectation for getting a high enough voltage to test the ACR's (two ACR's in series to get to the Thruster battery), I brought my Battery Tender from home and hitched it straight to the House bank for a couple days.

Today it was at full charge in the maintenance mode at 13 and a quarter volts. Yet the ACR's were still blinking. The Thruster battery was still down in the low 12's where it was three days ago. So I concluded that they will not work in series with a null node in between. I was all set to get scientific with some jumpers, but it was cold and lunch time. Besides I had new Engine and House batteries in the trunk of my car.

Once I get them installed I'll verify the ACR operation, and try to satisfy myself regarding the various charger priorities.
Thanks for joining me in this adventure. Still room for more comments.

 

[rpmerrill]

Last posting on this project, I think.

Pretty nice day today so I decided to install my two new batteries.

Took photos ahead of time, disconnected everything and got the leads all out of the way.
Thruster and engine batteries came out without having to "adjust" the house battery locations. But it was tight.

New batteries went in smoothly except the connection studs are a different size this year. I had to make a trip to the hardware store. I DISCOVERED THAT THE OLD NUTS WERE STAINLESS BUT I INSTALLED CAD PLATED. IS THAT CORRECT? Ive heard that you don't want stainless washers in the wiring stack but nothing about stainless nuts.

Anyway, I reached over to turn on the solar panel and put some tools away. The solar voltage jumped quickly and the amps rose nicely with it. (A bright sunny day.) With my battery bank restored to original condition, I was going to check to see where the solar charge actually goes. Before I could turn around and put my meter to the individual banks, I heard the ACR's click. All three banks were joined up. Even in the connected state, the house appeared to be a tenth or so higher than the engine and thruster. I think that's gonna be good enough for me.