Loss of power

Dmullen

Well-known member
Joined
Jul 23, 2021
Messages
48
Fluid Motion Model
C-32 CB
Vessel Name
Selah
When we were cruising yesterday, I had the AC distribution panel set with the inverter on along with the battery charging switch on. The strb/port outlet breakers were on along with accessories switch. As the day went on I noticed my plotter shutting down and when I tried to fire it back up, it didn't respond. Radio, usb outlets...dead. When I docked and plugged in shore power, changed the AC panel to shore power...and in a little while all was working. Somewhere I did something wrong and my house batteries were not charged and were not running the things that needed to be run. Anyone know what I did wrong?
Thanks,
 
If your inverter was on and the AC battery charger was on, then the battery charger was trying to charge the batteries from the same batteries via the inverter. The batteries will discharge much quicker than if you had everything turned off in this endless loop. This does not end well. To use the AC battery charger shore power is required. The solar charger uses the solar controller to charge the batteries, not the AC Battery Charger.

On many of the newer boats this situation is not possible as the panel wiring is such that the AC (Shore) battery charger cannot be run from the inverter. Never turn the inverter on at the same time the AC Power battery charger is on. It is a positive feedback loop that destroys batteries.

Hopefully your batteries have recovered fully.

Curt
 
Dmullen":39t103bu said:
When we were cruising yesterday, I had the AC distribution panel set with the inverter on along with the battery charging switch on......
Here’s what the inverter does: It takes direct current (DC) battery power and “inverts” it into alternating current (AC) power. The inverter is used when shore power is not available and AC power is desired. The inverter has a very limited capacity to produce AC power. On my 2012 R27, the inverter has a 1500 watt output capacity. That’s about enough to run the microwave.

Red Raven is correct— NEVER have the battery charger selected ON while the inverter is powering the AC power panel. It is a pointless exercise. When the engine is running, the alternator is charging the batteries. The battery charger is not used.
 
When the inverter takes power from the batteries (to then charge the batteries via the AC battery charger) power is consumed/lost in the conversion process leaving less power to go back into the batteries. As that loop continues the batteries simply have less and less power over time until... kaput! GF
 
Guys,
Thanks for your reply and the help. It is greatly appreciated. I will make the correction.
 
We went out the other day and spent the night. Took all the suggestions and the next morning our batteries were down. I use a Bipap machine and it seem to take the battery's down a lot. We used to motorhome and never experienced that... I believe they were at 7.8v, if I read my Garmin correctly. By the end of the day we couldn't even get the Garmin to work. We are electricity misers ...had everything off (included fridge) except charged phones. I even ran the engine to see if the alternator would charge it up...it didn't. Left the inverter off and the battery charger on. I'm thinking that the AGM house batteries and on their last leg or? Any thoughts out there.
 
The only time the battery charger should be on is when you have a 120V power source. This would be wither a generator, or shore power. The alternator charges the battery bank when it is running, but if you let the batteries get low, the ACR (Charge relay) won’t open to charge the house bank with the engine. Solar also charges with daylight, if you have it. Again, no need to run the battery charger unless you have shore power, or a generator running.

It does sound like your house batteries are toast.


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Elvin - you write “Again, no need to run the battery charger unless you have shore power, or a generator running.”

I never turn the battery charger switch at the panel to off when I leave the dock and disconnected from shore power.
Is that a problem or is it ok to leave it on in that case?
Does the charger run if not on shore power or generator?
Thanks.
 
palle":33zjari4 said:
Elvin - you write “Again, no need to run the battery charger unless you have shore power, or a generator running.”

I never turn the battery charger switch at the panel to off when I leave the dock and disconnected from shore power.
Is that a problem or is it ok to leave it on in that case?
Does the charger run if not on shore power or generator?
Thanks.
I’m not sure if it draws down your batteries, but I don’t leave the charger (or anything else on the 120V side) on when it’s not needed. I also connect to shore power whenever it is available, with the battery charger on.


Sent from my iPad using Tapatalk
 
Dmullen":3s6bfojq said:
We went out the other day and spent the night. Took all the suggestions and the next morning our batteries were down. I use a Bipap machine and it seem to take the battery's down a lot. We used to motorhome and never experienced that... I believe they were at 7.8v, if I read my Garmin correctly. By the end of the day we couldn't even get the Garmin to work. We are electricity misers ...had everything off (included fridge) except charged phones. I even ran the engine to see if the alternator would charge it up...it didn't. Left the inverter off and the battery charger on. I'm thinking that the AGM house batteries and on their last leg or? Any thoughts out there.

Your batteries may have been compromised from your last situation with running the charger while using the inverter. So the first thing I would do is do a load test on your batteries to determine their viability. Also, I have a c-pap and never used the boat inverter to power the c-pap. The inverter just standing idle will put a drain on the batteries. I use a small 12v inverter that I plug into a cigarettes' lighter outlet. Use one with enough wattage to power the machine. You also mentioned that your Garmin wouldn't even work? Why is your Garmin on while anchored? That is also a big draw. If you are using it for anchor drag alarm, don't. Use one of many Apps available for your phone that have an anchor drag alarm. My experience has been that after a night anchored with phones charging, phone on anchor alarm, c-pap and refrigerator I have 12.4V in the morning.
 
I never turn the battery charger switch at the panel to off when I leave the dock and disconnected from shore power.
Is that a problem or is it ok to leave it on in that case?

My wife always tells me to turn out the lights in a room after leaving and its not in use. That is a best practice I follow for anything electric on the boat. If I want to use a device, I head to the DC/AC panel and turn it ON, or if other switches are involved in the circuit I start turning things ON at the source closest to power and work my way down the circuit to the final device switch.

For example, to use the Microwave when the boat is on the hard (not common for most people but illustrative of the idea), I turn ON the Inverter Service switch by the batteries, turn ON the Inverter switch on the Inverter remote panel, turn the AC selector to INVERTER, turn ON the Main AC panel switch, turn ON the Microwave breaker (beep) and finally turn ON the microwave. When done with the microwave I reverse everything to OFF.

Not all devices are this involved but the point is to never leave things ON unless they are truly being used. That should preserve your batteries, familiarize you with your circuitry and help troubleshoot problems when things don't work.

HTH, GF
 
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