Recently installed a new fan and tank level monitor wired directly to one of two batteries for power. seems to work fine when connected to shore power but when not connected the tank monitor gives me error messages and the fan seems to operate at 10% speed. Does anybody know what this points to. battery meter on main circuit board says batteries are charging at 12 to 13 volts. thanks.
Electrical problem with new fan and tank monitor:
- Thread starter Ted10028
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If the battery charger says the batteries are being charged at 12-13v, the battery isn't accepting a charging. Depending on the type of battery you have charging voltage should be above 14v.
The low fan speed is highly suggestive of low battery voltage and the tank monitor gives an error message because the battery voltage is too low.
Some questions.
What type of batteries do you have? How old are they? What kind of charger do you have?
What is the resting voltage of the batteries? Use a multimeter to get the voltage at the battery terminals.
Not related to the poor performance of the devices but is related to the boat's safety is the number of wires connected to the battery terminal. The max number is four. Also check to be certain there is no SS washer between any of the connections and the battery. If there is a washer, it should be at the top of the stack of terminals.
In adequate wire size for the length of the wire run can contribute to low voltage at the fan and the tank monitor.
If I was a betting man, I'd bet on your batteries being toast and your charger outdated and battery killer charger.
The low fan speed is highly suggestive of low battery voltage and the tank monitor gives an error message because the battery voltage is too low.
Some questions.
What type of batteries do you have? How old are they? What kind of charger do you have?
What is the resting voltage of the batteries? Use a multimeter to get the voltage at the battery terminals.
Not related to the poor performance of the devices but is related to the boat's safety is the number of wires connected to the battery terminal. The max number is four. Also check to be certain there is no SS washer between any of the connections and the battery. If there is a washer, it should be at the top of the stack of terminals.
In adequate wire size for the length of the wire run can contribute to low voltage at the fan and the tank monitor.
If I was a betting man, I'd bet on your batteries being toast and your charger outdated and battery killer charger.
The problems are symptoms of low voltage and in the first post battery at 12-13v when on the charger and everything worked. Assuming the the voltmeter photo is while the charger is on, it shows a float voltage of around 13.6v. As for the charger, most of us have older boats built long before smart charging became available or affordable and there are a lot old chargers still murdering batteries out in the wild. If the battery is healthy the float voltage would be fine and the devices would run as expected. If the battery is toast, it can only accept 13.6 volts because the internal resistance is so high and when the charger is off, there is insufficient capacity to run the devices.Based on the meter photo,1980’s or?
A photo of the charger would answer the charger question. A resting voltage on the battery, after being charged and left unused for 24 hours would answer the dead battery question.
A fan draws maybe 2 amps and a the tank monitor about the same. If the battery were healthy and fully charged, adding a 4 amp draw to the battery should not cause the voltage drop at fan and monitor unless, the wiring was grossly undersized or otherwise poorly installed, or there are tremendous loads on the battery at the same time, or the battery has lost a substantial amount of capacity.
Any idea where I look for the charger or what it's likely to look like? I will get more specific information over the weekend.
Usually they are near the battery. The easiest way to find it will be to start and the battery and follow the wires. Eventually one set of Black and Red wires will lead to the charger. Get a photo of it and some photos of the tops of the batteries with the wiring.
If you have a digital multimeter, turn the charger off and read the battery's voltage every couple of hours for a while with no load on the battery. Also read the voltage under load with the fan and tank monitor on. The analog VM you have isn't accurate enough to get a good reading. You don't need a fancy expensive Fluke meter, just a mid price range meter from HD or Lowes. Avoid the cheap Harbor Freight meters. Klein makes a decent affordable meter.
On a 1975 boat, it could be anywhere th least owner wanted to install it.
Old boats require a good flashlight and the ability to follow a trail.
I’d start at the AC electrical panel. There should be a switch labeled “Charger or Battery Charger”. Looking behind the panel (For safety I’d be sure the electricity to the boat is off at the dock.) identify the wires the are connected to the panel breaker (should be red) and follow it form the panel to the charger.
You can also try to follow the wires from the battery to the charger, but likely there will be several attached to your battery and that may require several iterations to find the correct one.
my boat is a 2004 Catalina 320. It is hard to follow the wires since the circuit breaker panel is in the kitchen and all the wiring disappears behind the sinks stove and cabinets while the battery is on the other side of the boat. I can actually get in the sail locker and the transom locker. There is lotta stuff back there: heat pump air conditioner fridge compressor and some unidentified electrical stuff. i'll take pictures as a first step to getting it all sorted out and do some measurements on the batteries.
From the factory it was in the port lazarette in cockpit, mounted on the forward bulkhead. Most likely looks like this:
yes I think mine is there too although it is definitely not yellow. I will get a picture and post it here. Do you have a three stage charger and do you feel that is the best thing to have? can you recommend a specific brand and model? thanks!
A three stage charger is the only way to go if you like your batteries. Victron and Sterling/ProNautic (same charger, different labels) chargers are among the best. If was shopping for a new charger I would take a good look at the Victrons. Don't skimp out on the charger, the cost difference will be made up with the life of the battery.
here is my charger. I think I'm OK with it
are you saying the best way to determine the health of batteries is to look for 12 V without shore power, 14 V or so with shore power, and 12 hours without shore power under load?
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Well, it does not have 3 stage charging, as one would wish for.
Looked over the manual quickly, so don't consider this as an indepth review.
My take would be if you are careful you can make it work. But it is not what I'd keep in my boat if I could upgrade.
dj
Is to do a controlled 20 hour capacity test. Details of this are found on MainSail’s website. Under-Load Battery Voltage vs. SoC - Marine How To
Looks like an older model charger and not a brand I’ve heard of, but according to the manual at https://www.charlesindustries.com/wp-content/uploads/2021/04/LT-5000SP-1.pdf it is 3 stages, with an absorption voltage of 14.5 and float voltage of 13.6, when on the flooded lead acid setting. What this means is that when your batteries are deeply discharged the charger will gradually increase in voltage to 14.5, stay there until the batteries are charged, then go to 13.6 for as long as the charger is plugged in. If you see a pattern like that it’s a good sign the charger is working properly.
The quick test of battery health is how well they hold a charge when not on the charger. If you take the charger off and don’t turn on any house loads the batteries should stay close to 12.7 volts for quite a while. If you see them drop into the low 12’s it means either there’s a load you don’t know about or the batteries won’t hold a charge. The next level of test would be to put on some known loads (things like lights and instruments) for a few hours, and again make sure the voltage doesn’t sag too far. That’s not a very precise test but if you see, for example, 11.5 volts from the battery after a few hours of 5 amps of loads that’s a good indication the batteries are done. The real test to know their state of health is the 20 hour load test jssailem mentioned, though that can be time consuming and a little tricky to do.
The quick test of battery health is how well they hold a charge when not on the charger. If you take the charger off and don’t turn on any house loads the batteries should stay close to 12.7 volts for quite a while. If you see them drop into the low 12’s it means either there’s a load you don’t know about or the batteries won’t hold a charge. The next level of test would be to put on some known loads (things like lights and instruments) for a few hours, and again make sure the voltage doesn’t sag too far. That’s not a very precise test but if you see, for example, 11.5 volts from the battery after a few hours of 5 amps of loads that’s a good indication the batteries are done. The real test to know their state of health is the 20 hour load test jssailem mentioned, though that can be time consuming and a little tricky to do.
Charles Chargers were an early attempt to get to 3 stage charging. They were close, but no cigar. I installed one on the boat I owned 20 years ago as it was one of the best of the time.
The 3 stages in charging are Constant Current (Bulk), Constant Voltage (Absorption) and Float. Chargers start with putting out as many amps as the charger can produce, initially the voltage will be low and will gradually climb as the battery approaches 100% SOC. When the voltage reaches a predetermined absorption voltage, the charger maintains that voltage and lets the current gradually drop until it gets to a very low level, around 1 amp and then it shifts to a float voltage which provides a small current at a lower voltage, around 13.6v. The Charles charger starts by providing the full bulk charge and continues to provide that charge for 4 hours, regardless of the batteries SOC. And therein lies the problem. If the battery is deeply discharged to about 50% SOC the charger will work OK. However, if the battery is only partially discharged say to 75% SOC the charger will continue to apply a full bulk charge to the battery even after it is fully charged. That can cause the batteries to off gas the hydrogen and deplete the water in the battery.
This kind of charging would work OK for applications like golf carts where the batteries are deeply discharged before being put on the charger. However, for applications where the batteries are not deeply discharged, such as might happen after a long day sail, and then put on the charger, the charger will try to over charge the batteries.
That's part of the problem.
The photo of the battery suggests the battery is pretty old. There is a partially obscured sticker by the negative post that reads 4/1?, I wonder if that is the date the battery was installed. If so, the battery is at least 5 years old and even with the best of care it is reaching its end of life. Because the battery terminals are lead posts without an accompanying terminal stud, I suspect the batteries are older than 5 years.
The issues with the fan and tank monitor are likely due to diminished battery capacity, aka, a dying battery and the battery's death was probably hastened by the charger.
Edit: Forgot to add this from the Charles website
The 3 stages in charging are Constant Current (Bulk), Constant Voltage (Absorption) and Float. Chargers start with putting out as many amps as the charger can produce, initially the voltage will be low and will gradually climb as the battery approaches 100% SOC. When the voltage reaches a predetermined absorption voltage, the charger maintains that voltage and lets the current gradually drop until it gets to a very low level, around 1 amp and then it shifts to a float voltage which provides a small current at a lower voltage, around 13.6v. The Charles charger starts by providing the full bulk charge and continues to provide that charge for 4 hours, regardless of the batteries SOC. And therein lies the problem. If the battery is deeply discharged to about 50% SOC the charger will work OK. However, if the battery is only partially discharged say to 75% SOC the charger will continue to apply a full bulk charge to the battery even after it is fully charged. That can cause the batteries to off gas the hydrogen and deplete the water in the battery.
This kind of charging would work OK for applications like golf carts where the batteries are deeply discharged before being put on the charger. However, for applications where the batteries are not deeply discharged, such as might happen after a long day sail, and then put on the charger, the charger will try to over charge the batteries.
That's part of the problem.
The photo of the battery suggests the battery is pretty old. There is a partially obscured sticker by the negative post that reads 4/1?, I wonder if that is the date the battery was installed. If so, the battery is at least 5 years old and even with the best of care it is reaching its end of life. Because the battery terminals are lead posts without an accompanying terminal stud, I suspect the batteries are older than 5 years.
The issues with the fan and tank monitor are likely due to diminished battery capacity, aka, a dying battery and the battery's death was probably hastened by the charger.
Edit: Forgot to add this from the Charles website
thanks for the help. The meter on the central circuit panel says it is charging at about 13.6 V. Doesn't that mean it is charging at the appropriate voltage for fully charged batteries?