Correct Battery connection for Solar charger?

G

GaylesFaerie

Well-known member
Joined
Jul 20, 2020
Messages
579
Fluid Motion Model
C-28
Hull Identification Number
FMLT2701D112
Vessel Name
Gayles Faerie
I have a 2012 R27 recently purchased without the solar panel but with wiring installed from the batteries to the quarter birth where the Solar charger was located. The flexible solar panel the second owner had, stopped working, and he removed it and the controller (MPPT) prior to the sale. The first owner re-configured the batteries into two banks instead of three: 3 form the house bank and 1 for the engine. I purchased a rigid panel (100 watt to keep the batteries topped off over the winter) and have a question about the wiring at the battery side. The negative wire coming from the controller is grounded on a block next to the batteries. The positive wire terminates on a small block next to the batteries with two positive wires coming off its connection: one positive leads to the positive post of the engine battery and the other positive leads to the positive post of one of the house bank batteries. Both positive leads are fused (10amp). I was expecting only one positive lead to one of the battery banks - I thought the ACR would trip once that bank was topped off and the other bank would get its charge.

Is this wired incorrectly? Safe alternative? All comments welcome. Thanks, GF
 
The ARC does not trip when one battery is topped up! It trips when the voltage going into one battery is around 13 volts and allows current to flow into both sides. A solar panel will put out a voltage around 13 volts and so the ARC will combine the two lines. So you can connect the red lead from the solar panel to the house side and let the rest of the devices do their thing. Also things may be a bit different if you have a shunt and a current monitor system.
 
What John says is correct. Only one connection (to the house battery) is needed. In addition, if wired as you describe the house and engine would be combined and thus you really have only one battery bank (perhaps even with a questionable wire size?). Not what you want. I recommend you remove the connection to the start battery whether you add the solar panel or not.

Curt
 
I would agree with John and Curt. I recently installed solar on our R25sc, and it feeds directly to the house bank, letting the ACRs do the combining as originally designed. Make sure that the wiring from the controller to the batteries is as short as possible and a large enough gauge to minimize voltage drop. I added a Blue Seas resettable circuit breaker where the panel wires enter the cabin, for safety and as a means to disconnect the panel, because those wires are always live as long as there is light on the panel. Also, another resettable circuit breaker goes in the positive wire feeding the battery as close to the battery as practical, to protect from any shorts or damage to this hot wire,
 
It is not recommended to put any source of power on a switched side. The solar panel should be connected to the unstitched bus.
 
Thank you all for your quick responses. I think I've got my answer. I thought there was something weird about having the Solar charger positive battery wire going to two different banks, but I didn't realize that its actually combining them without the smarts of an ACR. I'll remove that wire going to the Starter battery.

I also recall from a boat electical series of videos on YouTube that power sources should be unswitched but fused. The videos were of Jeff Cote at Pacific Yacht Systems and covered the basics of many boat systems that I found very informative. See links below...

1 of 12 Batteries Part 1: https://www.youtube.com/watch?v=QZcf_gpbFf4
2 of 12 Batteries Part 2: https://www.youtube.com/watch?v=N5raZtxfCjY
3 of 12 Recharging your batteries: https://www.youtube.com/watch?v=OgsMBe-DFJo
4 of 12 Inverter/Charger: https://www.youtube.com/watch?v=u7BjwmOebfE
5 of 12 Charging Sources: https://www.youtube.com/watch?v=5WZpaWuYsME
6 of 12 Power Sharing and Monitoring: https://www.youtube.com/watch?v=uokjv6gPPEY&t=2024s
7 of 12 Troubleshooting: https://www.youtube.com/watch?v=RqkpH5-9xPY
8 of 12 Wiring Essentials: https://www.youtube.com/watch?v=lk4uuEYfCAQ
9 of 12 Troubleshooting Electronics: https://www.youtube.com/watch?v=Q0PtfTuZKqs
10 of 12 Troubleshooting Chargers and Inverters: https://www.youtube.com/watch?v=hhp0u8K9-lo
11 of 12 Troubleshooting Alternators & External Regulators: https://www.youtube.com/watch?v=IGsFNjRC0mY

I'm not an electrical wiz by any means but I learned enough from the videos above to posit the question on my Solar charger and feel somewhat empowered by your responses confirming my suspicions. Thanks again. GF
 
So I connected up the Solar panel using the previous wiring from the MPPT controller that led a positive wire to both the House bank (3 batteries) and the lone Engine battery. Everything seemed to work fine. I got 45w reading off the Solar monitor on a sunny November day in CT which I thought was pretty good.

Then I decided to take Curt's (Red Raven) advice and I pulled the fuse from the positive solar wire leading to the engine battery. When I did that the Solar monitor crashed to 0 (zero) watts. Keep in mind the solar positive is still connected to the House bank like recommended with fuse intact. When I re-insert the fuse into the wire leading to the Engine battery, the Solar monitor jumps back up to 45w.

Now I'm really confused.
 
Curt’s advice is definitely correct. Make sure the negative terminals of the house bank and engine battery are connected to each other (with appropriately sized battery cable) and to the grounding bus that the negative lead from the MPPT controller is connected to.

John
 
Hi, one important point, this R27 has a Victron battery monitor installed which includes a shunt to monitor current in/out of the house bank. Do not connect the start battery ground to the house battery ground, as this will bypass the shunt and cause bad battery state reading on the Victron. I was the original owner of this particular R27 and did some extensive modifications to the battery banks and connections. The house and thruster banks were merged, a Victron battery monitor was installed, and two 600A bus bars were installed to clean up the cable connections to the batteries. The 3 batteries that make up the house/thruster bank have only one cable on each battery terminal (except one battery also has the temp sensor for the battery charger). The engine battery has more connections due to the dedicated power feed for the engine control electronics.
The shunt is installed against the hull in the battery compartment:

The battery side has three cables, one to each of the house/thruster bank, each is equal length to balance current. Nothing else should be connected to this side. The load side has two cables that go to a 600A bus bar inside the genset compartment. 2 cables are paralleled to reduce voltage drop when thrusters are used. This is the ground bus bar at the aft end of the genset compartment. This is the common ground point for the boat, the thruster, house, engine, engine battery, bonding system, and genset grounds all connect to this bus bar.

Another bus bar is used for the house/thruster +12V connections. This is installed on the forward end of the battery compartment. Each of the three batteries in the house/thruster bank has an equal length cable connected to this bar, and the thruster feed, house feed, engine alternator, ACR connection, and genset all are connected. The Victron monitors the house battery voltage on this bus bar. Ideally, nothing else should be connected to any of the house batteries, the solar charge output should be connected to this bus bar.


I don't know what block you are referring to for the output of the solar charge controller with wires to the house and engine batteries. I would have expected to see one +12V connection to the house bank bus bar and let the ACR handle charging the engine battery. The negative for the solar charge controller should connect to the bus bar in the genset compartment, this will allow the shunt to monitor the charge current so the Victron can keep the battery charge status updated. If connected to the shunt it would be on the load side, not the battery side.
 
One more picture, this is the battery compartment as it looked when I sold the R27 to the gentleman that you bought it from. There was no solar panel at that time.
 
HRowland":1vmsinpa said:
Hi, one important point, this R27 has a Victron battery monitor installed which includes a shunt to monitor current in/out of the house bank. Do not connect the start battery ground to the house battery ground, as this will bypass the shunt and cause bad battery state reading on the Victron. I was the original owner of this particular R27 and did some extensive modifications to the battery banks and connections.
Click to expand...
This definitely supersedes my advice. The grounds still need continuity but any outside ground connection to the house bank should be on the load side of the shunt.

John
 
HRowland, thank you for that clear explanation and layout of the wiring. It definitely sounds like the Solar is not optimally wired. I've included two photos. The first shows the engine compartment today.

https://photos.app.goo.gl/FssAFeWXLkHDpBKE8

The wiring block I mentioned is mounted directly below the INVERTER fuse and shown in detail in the second photo.

https://photos.app.goo.gl/hB4CgqBWrXDK5qmj6

Both the Solar Pos and the Neg wires are split from the block and attached to a House Battery and the Engine Battery. So it does look like it is bypassing the shunt. A couple of questions: 1) in the compartment photo below the red Inverter switch is a large red cable terminating with no other wiring attached. What is its purpose? 2) the engine battery and the house battery to its left each have a second wire (small black) on the Neg post, are those the temp sensors you mentioned?

Last question, do I have to run down to the boat now and fix this? Will any equipment be damaged? Or can it wait a few days and I'll just get bad readings in the mean time?

Much appreciated, GF
 
Wow, that is just plain wrong. They connected the house bank and engine positives together, and the negatives together directly at the batteries. The current monitor shunt for the Victron battery monitor will not be accurate. I see each positive lead is fused, what happened is the first time there was a voltage difference between the house bank and the engine battery a high current would attempt to flow through the wires and fuses connected to the solar charge terminal block, blowing one of the fuses. The solar was then charging only one bank directly, the other would get a charge via the ACR.
To correct this I would first remove the wire from the solar charge block to the engine positive terminal. You can leave the wire to the house battery, it would be better for this to go the the positive bus bar at the forward end of the battery compartment but going directly to one of the house batteries is OK, the solar charge current is not that high so balancing between the 3 batteries should not be an issue.
Remove the ground wire from the solar terminal block to the house battery, this ground connection needs to go through the shunt so the Victron will be able to measure the charge going into the house bank. Ideally this would connect to the large 8 position ground bus bar in the aft end of the genset compartment, this is the tie point for all grounds on your R27. You should also remove the ground wire going to the engine battery from the solar terminal block.
From the solar charge terminal block you should have one +12V connection to either the house positive bus bar or one of the house batteries positive terminals. The ground wire from the solar terminal should go to the ground bus bar in the genset compartment, or less ideal, the Load side lug on the shunt that is against the hull.
That terminal post in the lower left part of your picture is the 12V power feed for the aft thruster, it has two cables attached, one goes forward along the hull up to the aft thruster fuse in the genset compartment, the other cable goes back to the thruster.
You dont have to fix this right away, as long as you see charging from the solar controller it will charge the batteries, which ever one has the good fuse will charge first, the ACR will then connect the other bank when the connect threshold is reached (this is based on voltage/time, see the ACR data sheet at Blue Sea, note this is an early model since Blue Sea changed the voltage/time thresholds). Also note that the Victron is not monitoring battery charge state or current properly until the connections are correct.
Another note, you can activate service with Siren Marine to use the MTC remote monitor/alert system that is installed. You can then monitor battery voltage and other items from an app you your phone and set thresholds to get alerts. You can confirm that the solar panel is keeping the batteries charged.
 
Boat was hauled Friday. On Saturday I made the modifications suggested by HRowland. I removed all Solar connections from the batteries and hooked the Solar controller positive to the Positive buss bar in the Battery compartment and the controller negative to the Negative buss bar in the Genset compartment. All works. Saturday was sunny and the sun is getting pretty low in the sky but the Solar charger was showing as much as 57 watts (roughly 4+ amps?) which I hope will keep the batteries from discharging much over the winter. The Victron was reading 13.8V. The panel is 100W and it will be exposed outside of any covering. Thank you! GF
 
Pilotnavigator":3hiuuwn3 said:
The ARC does not trip when one battery is topped up! It trips when the voltage going into one battery is around 13 volts and allows current to flow into both sides. A solar panel will put out a voltage around 13 volts and so the ARC will combine the two lines. So you can connect the red lead from the solar panel to the house side and let the rest of the devices do their thing. Also things may be a bit different if you have a shunt and a current monitor system.
Click to expand...

I have a Ranger 21 with an ACR and one house battery and one starting battery. Should I connect the positive and negative clips to the House Bank or Starting Bank? My main concern is keeping bilge pumps going on a buoy in winter.

Small boat...no inverter...no generator.
 
Good question, normally I would connect the red lead to the house positive and the yellow lead to the common negative bus bar for the solar controller. But if the boat was to be left for an extended time in the water there is a slim chance the ARC could fail and the pump would drain the battery. In that case I would connect the controller to the pump battery. When the summer season starts again you could swap it back to the house side.
 
I can trace but I assume the pumps are on the house bank? 2010 Ranger 21 EC.
 
Not necessarily, original setup was only one house and one starter, so the assumption would be the starter has less use when not running.if you, like me, added more house batteries then moving the pump to the house side makes some sense in your case. But again if things go wrong... if you are leaving your boat for an extended period in the water where no one is around periodically I would suggest one of those remote alarm systems to notify you of problems.
 
Harley, I'm no expert, but I suspect that if you have a working ACR you can connect to either battery. GF
 
Working arc is the question, there is a remote chance they will fail, or if the sun does not shine for several days and rain, likely at the same time, the starter battery could drop to fatal level and the ARC may not connect to it when a charge is detected on the house side. No solution is perfect.
 
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