house battery not charging

Kushtaka

New member
I have a mini ACR, and have discovered a very new anxiety!! My start battery is charging and isolating just fine, but my house battery is not charging at all. I've verified this with meters to each battery while charging via alternator, and with the motor off.

This is new! Just happened yesterday. I was out fishing, watching sonar, listening to the radio, and then went to haul my anchor, and things started shutting off, and the windlass labored.

I had to connect both batteries with the emergency switch to get the anchor up. I had just set a longline as well, and today I had to go out to haul the longline and do the same. I kept both batteries connected the trip out to get the house battery charged as well.

The new anxiety I'm having is the fact that my fuel line passes right in front of my charging relay. I'll figure out how to re-route the fuel later, but I really want to not worry about this issue.

I have yet to get into it. My plan is to work through the wiring diagram from the house battery backwards, and find something loose, tightening everything as I go.

Is anyone familiar enough with these systems to tell me precisely where to look? My setup is a little tough to access, and if there were a part I could avoid taking apart I'd be happy.
 
Your plan of cleaning and tightening all connectors is the best way to start. It sounds as if the ACR is not working--but this could be a connection--as well as a failure of the ACR.

Take the your digital volt meter and check the voltage on the start battery, and then the house battery with the engine running, after cleaning the connectors. If then the voltage on the two batteries is not the same, that suggests that the ACR is bad.

Also there is the possibility that the house battery is failing. Put it on a charger, and bring it up over 24 hours to be sure it is at full charge. Put a load tester on it to be sure. How old is the battery? What size is the battery?
 
The battery is brand spankin' new, and charged quite well for three or four trips. The ACR is less than a year old, but still, could be bad.

It seems like the switch should be fine. Does that seem right? I think I'll just go through the ACR And put it back together and test. I may kick myself for not taking the switch apart, but it seems to be doing its job.

Oh boats.
 
ssobol":z3xc578c said:
I just have a switch and manage the battery charging manually. An ACR is just one more thing to go wrong at a bad time.

This is the school I go to as well! I did have a off, 1, 2, both switch fail once on the 1 position. That was from overheating though. Trying to start a 6 cyl. after running out of gas(with a mechanical fuel pump). After that I installed an electric inline fuel pump strictly for priming if one tank sucked air.

You can check your switch function with an ohm meter or continuity checker.

I agree with Bob as well - charge the battery up from a shore power source then test. If its new - probably OK, but sometimes auto rated batteries can develop a bad or internally shorted cell from excessive vibration.

Regards, Rob
 
I'm thinking maybe you're mini ACR is not rated for 2 batteries, it either failed or is malfunctioning.

If you don't find any obvious bad connection, try bypassing the ACR.

Looking at your album it appears you only have a single 2 way on off isolator switch.

In bypassing the ACR you'll have to attached you're starting and house battery together as one.

I assume each battery has its own breaker switch, this is a must!

If this solves your charging problem I would suggest installing a 4 position switch (1,both,2, off).

With this switch installed you can manage your batteries as you see fit, I only suggest leaving the switch in the both position whenever underway that way both your batteries will always be topped off.

Let me just say I'm not a big fan of automatic charging relays.
 
ACR could be bad or mis wired or something wrong with battery

Battery can tested with load tester and newer high end testers give a printout.

I would contact the ACR company tech support
 
I use a group 24 start and a group 31 house. I check voltage of both independently before starting. Normally I leave switch on 1 until out of the marina to top off the start battery. Then switch to 2 for rest of cruise to charge house. I don't advise charging 2 different size/capacity/type/age batteries on the same circuit. It can result in one being overcharged and one undercharged. If the start battery is almost fully charged and the house depleted - the higher voltage of the start battery will raise the combined voltage in the circuit and make the alternator think the house battery is more charged than it really is.

To avoid this I have on occasion used a charger plugged into my invertor to charge or maintain the one bank.

Regards, Rob
 
Robert H. Wilkinson":2rwj3ybf said:
I use a group 24 start and a group 31 house. I check voltage of both independently before starting. Normally I leave switch on 1 until out of the marina to top off the start battery. Then switch to 2 for rest of cruise to charge house. I don't advise charging 2 different size/capacity/type/age batteries on the same circuit. It can result in one being overcharged and one undercharged. If the start battery is almost fully charged and the house depleted - the higher voltage of the start battery will raise the combined voltage in the circuit and make the alternator think the house battery is more charged than it really is.

To avoid this I have on occasion used a charger plugged into my invertor to charge or maintain the one bank.

Regards, Rob

Don't over think this whole thing, I have 3 batteries 2 same one outlier all nominal. Batteries are 5 + years old and check out fine. Generators are history, alternatobrs rule. Have never overcharged or cooked a battery on any boat.
 
Currant takes the path of least resistance. Think of your batteries as jugs of water. Lets say you have 3, one full, one almost empty and the other about half full. Now think of current as water flowing in a pipe, this pipe is attached to all three batteries. As the current flows the jugs (batteries) charge.
No current enters the full battery because it's full, but the alternator (flow resistant sensor) detects no resistance because the current is flowing into the other two batteries.
The half empty an empty batteries fill at the same rate until the half empty fills, than all the current, being pushed by amperage, fills the empty battery.
The alternator detects the flow resistance and shuts off the flow of current.
 
.....than all the current, being pushed by amperage.....

Slight correction -- "...being pushed by VOLTAGE....."

To continue with your metaphor, think of amperage as the amount of water flowing per second in the pipe, and voltage as the pressure in the pipe. Pressure pushes water in the pipe.....voltage pushes amps in a wire.

Another image that works is imagine water flowing into a bucket. How fast the bucket is filling is analogous to amps (amp = coulombs/second -- with coulombs being the number of actual electrons, and with electrons being the water itself in this analogy). The force of the water coming out of the hose (a dribble vs a stream that would shoot 10 feet) is analogous to volts. Note that the a bucket can be filled in the same amount of time in 2 ways: large diameter hose at low pressure (lots of amps but low voltage); or small diameter hose with high pressure (few amps at high volts).
 
The alternator detects the flow resistance and shuts off the flow of current.
It is a bit more complicated. The alternator is dumb--it just produces the power. Most outboards do not have a sophisticated regulator, as many inboards, our cars, and most battery chargers do. This is why the outboards continue to put out 14.4 (up to 14.8 in some cases) volts even when the battery is approaching full charge. This can lead to excess charging, overheating and boiling off of electrolyte. But in reality, most of us do not run our boats enough to cause a problem.

The good alternator regulator--or charger--starts with a bulk current, which is increasing voltage as the device puts out maximum current (allowed by the batteries resistance). The outboard motor basically stays in bulk charge state.

The more sophisticated regulator/charger then goes into absorption phase at about 80% state of charge. There the voltage remains constant, and the amperage decreases as the resistance of the battery increases. A good regulator/charger will have a temperature feedback circuit to prevent battery overheating. This last 20% of charge is much slower, and the major reason that we rarely fully charge the boat batteries as we run the boat, especially if there are large draws, such as refrigeration.

The final stage is float, where the battery is up to full charge, and this maintains the voltage above the batteries steady state voltage (which is 12.6 to 12.7 at full charge)--generally about 13.2 to 13.4 volts.. To charge the battery that last 20% is a good reason to put your batteries on a smart charger between uses.
 
Dr. Bob, FTW!

I've noticed that when in normal mode (now just charging the start battery) I draw over 14 volts on the boat's gauge. When I run in emergency mode (which I now need to do to charge both batteries) I get around 13.5 volts.

Makes sense. I don't think the acr provides any voltage regulation.
 
I emailed Blue Seas and got a response the same day with a very simple troubleshooting guide that I'm to go through. Once I do, I'll end up with a pile of data (mostly voltages measured under different circumstances). I'd be happy to post it here, but I don't see how to upload a pdf. Any ideas?

So far, a very good experience with their customer service. At least there's that.
 
bad terminal connection the wire from my ACR to my house battery. ACR was fine the whole time, easy fix! I could probably didn't need the troubleshooting guide, but I used it as I went through, and I actually identified the issue on my meter because i did.

Overall, it was a very minor issue that showed me 3 things:

1. The ACR unit is robust, and has that redundancy to make my system work in a pinch when a connection is lost.

2. I definitely got lazy making connections. All of my terminal ends were great, except for this one. I think I was probably tired when I made it, or I made that one first, and got better as I went. I recall having some issues with my butane soldering iron at first, maybe I didn't get things hot enough.

3. Customer service from Blue Seas was outstanding. Fast, knowledgable, helpful, and available. In the future I'll be likely to use their stuff again, even if it costs more, because of their great showing on this minor issue.


Aside from that, I learned that I am not all that comfortable with a fuel line running in front of my switch/ACR, among all that potential for sparks. If I had an electrical fire because my connection was loose instead of parting, and it would have become catastrophic very quickly.

this is the line that runs out my fuel selector switch to my racor (mounted in my splashwell). It will be a bit of a chore to re-route it, and then I still have the selector and hoses in the same compartment.

Can I wrap the fuel line with anything to protect it if there is a fire? I'm concerned that I wouldn't be able to tell if a small fire started in there while underway, can anyone recommend a sensor I can put in that compartment that would alarm in the cabin? Am I just being overly cautious here? Maybe I just need to be talked down?

Thanks for all the input. This was a pretty easy one once I got in there. The toughest part was taking everything apart just to access the terminals to test.
 
Glad you found a simple problem. At the Hontoon Island gathering I saw at least 5 boats which were having electrical problems. Every one was a bad connector--either corrosion or not properly tightened.

I have my ARC and transfer switch, in the same compartment (Starboard Lazarette) that my Racor and the fuel line goes in and out of. But the electrical circuits in and out are protected by circuit breakers, and the hoses are some distance from the (about 6" closest) from the ACR and negative circuit shunt for the Xantrex Link Lite. I don't worry about that; the best way to prevent electrical fires is to have adequate circuit breakers. When we are not using the boat for any length of time, we disconnect the batteries. But fire aboard is always a grave danger.

On our larger boats we hadAqualarm systems. These had multiple remote systems, connected to a very loud bell. Included in these were water flow for the main engine, generator, several remote high temp alarms, including exhaust and engine room.

There is a standalone Aqualarm system with 135 or 195* fire/temperature sensor and remote panel with alarm buzzer for $84. That is probably your best bet for a marine high temp alarm. (Although not listed as a package, you probably can get the smaller remote for the same deal0.

I am not sure I would trust a home fire detector in the marine environment.

So was this a bad solder connection? Was there corrosion in the joint? Are the lugs both soldered and crimped?

Last week I was called to investigate why an inverter was not working. The owner was out of town, and it was running the freezer on a concession trailer. I could not find a bad connection--but I failed to take the inverter off its mount on the wall, and check where the cable lug was bolted to the inverter input. The owner had failed to properly tighten this connection...(reason a lock washer is suggested under the nut on these connections.)
 
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