Electrical Issues?

Jfrano

Well-known member
Joined
Aug 12, 2018
Messages
473
Fluid Motion Model
C-30 CB
Vessel Name
June Sea
So my house batteries on the hook for a night will drain down to
12.1 V from a fully charged marina stay on shore power followed by a 40-50 mile run before staying on the hook. The most significant draw is the fridge set to 4 and the wine cooler set to 58 degrees, add the other smaller items ie led interior low Lights, led anchor light, CO detectors, occasional bilge pump, toilet etc. not clear where power is going.
Also use coffee maker 2 times a day, for about 2 minutes.- microwave typically when the engine is running.
 
It is highly recommended to get a smart battery monitor to measure and track your battery usage and report remaining AH. This is the one that most people get: https://www.victronenergy.com/battery-m ... -712-smart

You can track real time power usage, turn on/off devices, and track whether you are getting the expected life out of the batteries you have.

Installation requires moving the negative battery cables to all run through the provided shunt that measure power usage. I would recommend installing a bus bar, transferring the power cables to it, then run jumpers from the bus bar to the shunt and the shunt to the battery bank. You will have to be comfortable making 00 battery cables and have a hydraulic crimper and heat gun with some heat shrink, or pay someone to install it for you.
 
That wine cooler is a power hog, more than the fridge.
When mine started dropping that low overnight I diagnosed it as at least one bad battery and replaced them all. Hopefully that's not the case with you.
 
If your R29 is 6 years old and you have the original house batteries it may be time to replace them. Especially if they have been fully discharged once or multiple times.
How to reduce power consumption when not on shore power:
1. Make coffee by boiling water using propane cooktop and then use French press. Works great and coffee tastes better than what you get from Keurig.
2. Don’t use the microwave - even with engine or generator running.
3. Make sure wine cooler enclosure is really well vented. The wine cooler doesn’t work very well at cooling and it uses up more power if the wine cooler is in a sealed cabinet area. In most FM boats they put the wine cooler in a sealed enclosure.
 
I had all 6 Agm batteries replaced a month ago.

The starting battery and the thruster battery always seem to be over 13 volt's.
I can run the boat for a full day and it seems like the alternator isn’t charging the house bank.
Is there a way I can check the wiring?
 
In the compartment with your battery switches should also be located your ACR's (automatic charging relay) which are what combines your batteries together to allow your alternator to charge them all while underway, then disconnects them once no longer charging (*other scenarios can also cause disconnect).

Each of the ACR's have an indicator LED which corresponds to the operation status (label on the inside of the removable cover for reference). There should be a small ground wire connected to each ACR, and if this somehow became disconnected it would prevent it from operating leaving the house bank to charge only from solar and the inverter/charger on shore power or generator.
 
The reading that you are speaking of I assume is from a battery Volt meter. This reading is battery voltage that includes voltage drop from all users.

Example: You just finished a cruise of 4 hours. Your battery banks are all fully charged. You drop your anchor the volt gauge reads 13.0. The refrigerator is on the chart plotter is on the radio is on plus a few other 12V users. Let's say 7 amps of power coming off of your Lead acid batteries. The volt meter will quickly show a voltage drop of a couple of volts.It stays at this reading for a while and then drops as more stored power is removed. That drop is the percentage of battery discharged. This does not mean that your battery has depleted to that percentage of discharge. It means that the voltage drop is caused by the load plus the time the load is put on the battery. Checking battery voltage when 12Volt users are using power will not give an accurate reading of battery percentage used. You must remove all users let the battery sit and stabilize then check battery voltage. 12.4V or above would indicate you still have more than 50% charge.

As previously stated in a post. The simple plus accurate way to monitor your battery state when anchored is by installing a Victron battery monitor. You program, type of battery, size and battery capacity. It will monitor charge and usage amounts. Battery voltage is important to know but it does not tell the complete story.

I have a Victron monitor attached to my house bank that has 400 ah capacity. Once the battery information is programed into the monitor it will read, battery voltage, amps going into the bank when charging, amps going out of the bank when charging, amp hrs left, Battery discharged percentage, battery temperature and much more. When I am at anchor, in the morning I look at the battery voltage. The voltage can be as low as 12.2 V but the monitor reads I have 70% battery capacity left. I look at how many amps used usually around 120 ah. I switch it to read amps, -9 amp, meaning 9 amps is needed to run refrigerator and freezer at this time . I then turn the inverter on and start coffee the voltage is now down to 12V and the amp draw is now about 60 amps for about 10 minutes while coffee is brewing. inverter off voltage comes back up to 12.1 or 12.2 V, Battery capacity 65% as I just used 20 ah more. As soon as the sun comes up and the solar kicks in the amp I start to see amps in the positive and the battery bank starts to charge.

I don't think your reading of 12.1 V is out of line if you have 12Volt users on line when you are reading this voltage.
 
Full_O_Fish":279bo9vu said:
In the compartment with your battery switches should also be located your ACR's (automatic charging relay) which are what combines your batteries together to allow your alternator to charge them all while underway, then disconnects them once no longer charging (*other scenarios can also cause disconnect).

Each of the ACR's have an indicator LED which corresponds to the operation status (label on the inside of the removable cover for reference). There should be a small ground wire connected to each ACR, and if this somehow became disconnected it would prevent it from operating leaving the house bank to charge only from solar and the inverter/charger on shore power or generator.

Removed the two ACR covers, each one has three terminals; each one only had the ground wire connected . The first terminal is labeled led, I don’t actually see a led . Is this suppose to be on the body of the ACR or remotely connected via the led terminal?
Ran the engine and the generator to see if I would see any led .., nothing,
When i start the generator the inverter display goes into “bulk charge” mode.
 
Have been underway for a few hours. House bank was 12.32 when we left. We’ll see what it’s at when we tie up.

Am noticing that at the same RPM 1720 the voltage varies from like 12.69 to 13.17. Not sure if this is normal . Would have expected a more constant output at same rpm?
 
My only (small) gripe with this forum format is that you can't offer "applause" when another post is just so complete, so clear, and yet so simply written that it deserves an 'attaboy'. We've all read a hundred (or more) posts about battery monitors. The one from Brian a few posts up from this one deserves some genuine applause, in my book. (As I recall, the Trawler forum offers this option in some kind of 'check the box' format.) Nicely done, Brian.
 
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