I religioulsy check my batteries every two weeks. They read 13.78 volts. The volt meter on my electrical panel reads .3 volt less. The meter is not able to be adjusted. I called Hunter and ordered a new meter thinking that the meter was not working properly. It cost $50!. It arrived today and I replaced the old with the new. I put my meter on the old meter and it read 13.56 volts. It was the same with the new meter. The new meter read the same as the old one. My question: Is there a voltage drop from the battery to the meter that would account for the .3 volts? John Richard s/v Jack's Place.
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Daniel Jonas
Meters
John, They are on my 356. I monitor with a Link 2000 and the meters in the circuit breaker panel are about that much lower than the Link indicator. Dan Jonas (S/V Feije II)
John, They are on my 356. I monitor with a Link 2000 and the meters in the circuit breaker panel are about that much lower than the Link indicator. Dan Jonas (S/V Feije II)
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Steve
Wire Size
The voltage drop is caused by resistance in the wire. The smaller the guage of the wire, smaller number of stands, and the longer the run, the bigger the drop. The West Marine catalog has a table to provide a percentage of drop you can expect with the size and length of wire.
The voltage drop is caused by resistance in the wire. The smaller the guage of the wire, smaller number of stands, and the longer the run, the bigger the drop. The West Marine catalog has a table to provide a percentage of drop you can expect with the size and length of wire.
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bill walton
agree on wiring
The wiring used to run from the battery to the meter caan easily cause the discrepancy. I'm somewhat concerned about the high voltage reading you obtain in your biweekly visits. That seems high for a float voltage which I would expect to be 13.2 to 13.4. /are you experiencing a high degree of electolyte loss?
The wiring used to run from the battery to the meter caan easily cause the discrepancy. I'm somewhat concerned about the high voltage reading you obtain in your biweekly visits. That seems high for a float voltage which I would expect to be 13.2 to 13.4. /are you experiencing a high degree of electolyte loss?
J
John Richard
To Bill Walton
Bill, I take the voltage reading directly at the battery terminals. The reading at the batteries (two 4D's and one dedicated starting) is 13.75 to 13.78 volts. The meter on the panel reads 13.3 to 13.4. The batteries use little, if any, fluid so there isn't any loss of electrolite. Also, one of the 4D's is new and the other is a year old. John Richard
Bill, I take the voltage reading directly at the battery terminals. The reading at the batteries (two 4D's and one dedicated starting) is 13.75 to 13.78 volts. The meter on the panel reads 13.3 to 13.4. The batteries use little, if any, fluid so there isn't any loss of electrolite. Also, one of the 4D's is new and the other is a year old. John Richard
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Stan
Junk Meters
To put it bluntly the analog meters that come with boats do little more than indicate that a battery exists. The voltage drop is not the problem due to the high impedance of the meter. The wires that the LINK2000 uses to monitor the voltage are actually smaller than the wires used by the analog meter. Again high impedance (i.e. virtually no load) allows accurate voltage measurement. If you were to install a quality digital meter in place of the analog one using the same wiring the voltage measurements would match your multimeter. Or better yet. To prove a point. Use your multimeter and measure voltage right at the analog meter.
To put it bluntly the analog meters that come with boats do little more than indicate that a battery exists. The voltage drop is not the problem due to the high impedance of the meter. The wires that the LINK2000 uses to monitor the voltage are actually smaller than the wires used by the analog meter. Again high impedance (i.e. virtually no load) allows accurate voltage measurement. If you were to install a quality digital meter in place of the analog one using the same wiring the voltage measurements would match your multimeter. Or better yet. To prove a point. Use your multimeter and measure voltage right at the analog meter.
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Dan
Meters
I tend to agree that it is the voltage meters. My Link 2000 does have pretty small wires and the distance is just over 25' to the batteries, but the voltage is very accurate. The wires for the voltage meters in the panel just run down about 4' to the battery switch, but they read low. I do wonder about readings of 13.78 at the batteries. I have two 4D agm's and my float voltage is 13.2 from a multistage charger. Dan Jonas (S/V Feije II)
I tend to agree that it is the voltage meters. My Link 2000 does have pretty small wires and the distance is just over 25' to the batteries, but the voltage is very accurate. The wires for the voltage meters in the panel just run down about 4' to the battery switch, but they read low. I do wonder about readings of 13.78 at the batteries. I have two 4D agm's and my float voltage is 13.2 from a multistage charger. Dan Jonas (S/V Feije II)
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cole
Whats the voltage on the meter terminals?
Try reading the voltage at the panel meter and compare it to the batts, using the same DVM or fluke you shouldnt see much of a drop. I dont think you will see a loss of.3 vdc. You may look for a better meter, look to simpson or newport, they have some pretty nice meters that can be calibrated, zero and span, from the front of the panel.
Try reading the voltage at the panel meter and compare it to the batts, using the same DVM or fluke you shouldnt see much of a drop. I dont think you will see a loss of.3 vdc. You may look for a better meter, look to simpson or newport, they have some pretty nice meters that can be calibrated, zero and span, from the front of the panel.
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Bob
Check connections, verify results
Generically speaking, all these suggestions have merit. Generally, meters draw a minuscule of power from the circuits being measured. Like the current draw of modern instruments would be less than a few milliamps at worst. Digital meters in the microamp region, some much less. (milli = 1/1000 , micro = 1/1000000 ). In addition to these suggestions, keep in mind that analog meters "work" in a similar manner to a dc motor, in that the current developed in the instrument can be affected by other electric fields in their midst. That two meters by the same company has the same error, I would suggest verifying the accuracy of the meter at three points: Near zero, mid range, and max range. If it is consistently off by .3 v, then check for an adjusting screw in the center of the meter face. If an digital meter, the dc interference doesn't ring true, but could still have an adjusting screw. Also check the face and look for a specification, may look like x ohms / per volt. As already mentioned, you could have a multiple break in the wire. Some methods of connecting wires tend to "damage" the strands. It is possible, though not statistically likely, to have a few broken strands of wire if it is crimped. Try "paralleling" each wire to its source with a wire jumper using alligator or crocodile jaws. If the meter changes, then replace or recrimp the wires. If you check the meter, and find the differences between low, mid, and high to be different amounts, I'd then check for 2 (two) adjusting screws, but normally these should be factory preset. I'd then call the manufacturer or dealer of the meter. when checking the "specs" on a DVM or digital volt meter, be very careful not to confuse the "number of digits to the right of the decimal point with accuracy". The two are implied as being related, but not necessarily. Often times the basic accuracy may be stated as "accurate to within 1/1000 or 1 Micro Volt*", and the star goes to the fine print of "*when used on the 0.1 range". Not much good on the 50 volt range. (Sorry this is so long. It may be more than you need.). If more is needed, you can email me through the HOW member forum. Bob
Generically speaking, all these suggestions have merit. Generally, meters draw a minuscule of power from the circuits being measured. Like the current draw of modern instruments would be less than a few milliamps at worst. Digital meters in the microamp region, some much less. (milli = 1/1000 , micro = 1/1000000 ). In addition to these suggestions, keep in mind that analog meters "work" in a similar manner to a dc motor, in that the current developed in the instrument can be affected by other electric fields in their midst. That two meters by the same company has the same error, I would suggest verifying the accuracy of the meter at three points: Near zero, mid range, and max range. If it is consistently off by .3 v, then check for an adjusting screw in the center of the meter face. If an digital meter, the dc interference doesn't ring true, but could still have an adjusting screw. Also check the face and look for a specification, may look like x ohms / per volt. As already mentioned, you could have a multiple break in the wire. Some methods of connecting wires tend to "damage" the strands. It is possible, though not statistically likely, to have a few broken strands of wire if it is crimped. Try "paralleling" each wire to its source with a wire jumper using alligator or crocodile jaws. If the meter changes, then replace or recrimp the wires. If you check the meter, and find the differences between low, mid, and high to be different amounts, I'd then check for 2 (two) adjusting screws, but normally these should be factory preset. I'd then call the manufacturer or dealer of the meter. when checking the "specs" on a DVM or digital volt meter, be very careful not to confuse the "number of digits to the right of the decimal point with accuracy". The two are implied as being related, but not necessarily. Often times the basic accuracy may be stated as "accurate to within 1/1000 or 1 Micro Volt*", and the star goes to the fine print of "*when used on the 0.1 range". Not much good on the 50 volt range. (Sorry this is so long. It may be more than you need.). If more is needed, you can email me through the HOW member forum. Bob
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