TV and Soundbar dropping voltage to 11.5v

[jaminb]

I am currently sitting on my marina berth with electric hook up and battery charger on. I don't normally use the TV and Soundbar but have just noticed that they are dropping the voltage to 11.5v - should I be worried? If I turn off the voltage reverts back to the normal 12.6v which the charger can maintain with the heater, fridge, lighting etc.

New 3 x 80amp batteries fitted this time last year and I make a point of not letting them drop below 12v during normal sailing / off the charger.

thanks

 

[Robih]

Something wrong there, the charger should be maintaining about 13.1v. It sounds more like a resistance problem perhaps - are you sure the charger is only outputting 12.6v? Maybe it’s 13.1v at the batteries but a lower V at your testing location? Are you sure that there is a good 240v power supply to the charger? It almost seems as though the charger isn’t working at all.

 

[harvey38]

Sounds like you are drawing too much current for the bank to sustain, are the three batteries in one bank, what output charger are you using and what is the combined current draw of the heater, fridge, lighting etc?

 

[Sandy]

What is the output voltage and amperage from the battery charger?

You will have 240 volts at 16 amps on your shore power. Depending on your battery charger you should be getting 15 or 30 or more amps at about 14 volts DC.

Is the TV/Sound bar going through an inverter?

What is the power consumption of the TV and sound bar?

Can the TV/Sound bar be plugged into the AC?

Your other stuff should be drawing about 10 amps max.

Do you know the total power draw from the battery.

I've been posting on another thread today about lithum batteries, perhaps that is the answer... (No really I don't think they are).

 

[William_H]

Is the OP measuring voltage at the battery terminals. Any other measure point may be affected by volt drop in the wiring. If volts at battery terminal is dropping then yes charger is not keeping up. So if voltage is measured at panel then what loads are common to that measure point? (where a volt drop under load may occur. All a bit complex. need more info. ol'will

 

[KompetentKrew]

Is the OP measuring voltage at the battery terminals.

My first thought too.

There's deffo something odd here, but a TV and speaker shouldn't be drawing that much - especially since the charger is on.

The voltage across the battery terminals is the real voltage - measure it using a handheld multimeter. If you're getting 1v or 2v lower by measuring further down the circuit then it's probably due to a bad connection - corrosion or something.

Also consider fitting a Vicrton SmartShunt or similar.

 

[KompetentKrew]

If I turn off the voltage reverts back to the normal 12.6v which the charger can maintain with the heater, fridge, lighting etc.

What kind of heater is it, please?

 

[Refueler]

First of all - please give details of the charger ... what is it rated to output ... is it a smart charger that bulk / floats / maintains ? Those are important factors.

Soundbar ? What sort of wattage ? Some Soundbars I know are WOW !! you have how much !!!

OK .. jokes aside ...

12.6V maintained with fridge / heater / lighting on ... I assume the charger is now in maintainance mode. Is that 12.6V set by user or default ? It sounds to me as if already the load on system may be at max charger can cover ... I would expect the voltage to be a bit higher ... nearer 13.0V
The TV and soundbar is just basically the straw that breaks the Camels back .. dragging that voltage down ... lower than I would expect - but if the voltage is staying at that and not dropping further - then system is just about coping ... but IMHO - not good.

What happens when other items such as fridge are turned off ? Do you have an ammeter in the system to show load draw ? What is voltage when only TV and soundbar on ?

 

[footsoldier]

measure it using a handheld multimeter

The best advice so far. Assuming you are relying on some sort of built-in meter within your set-up, it could be giving erroneous readings.

 

[jaminb]

Wow thanks for all your kind assistance. The charger is a Chargemaster 12/25-3. Reading the manual the Output Voltage is adjustable from 0-15.5v.

I get 13.6v when the alternator is charging and briefly over 14v from the Rutland when it is really windy.

Efficiency at full load is claimed to be 13.25v and 25A

TV and Soundbar are 12v and pretty puney.

Heater is Webasto diesel, fridge thermostat ensured that it wasn't drawing.

I was reading off the LED disp;ay on the switch panel rather than a meter reading from the battery.

As the evening wore on the voltage crept back up to 12.8v.

thanks for your help

 

[jaminb]

Meter on the battery says 13 volts so must be the crappy aftermarket control panel that is duff or is dropping in the the power supply to this. I have actually no idea where the source for this second panel comes from. Further investigation required.

Thanks for your help

 

[William_H]

Take your multimeter and check at battery terminals. (done) now check voltage at back of switch board ie near meter. Does the measured voltage compare to volt meter reading? If not then dud meter. If yes and voltage is lower at panel then volt drop in wiring. Check connections fuse holders switches etc for volt drop and don't forget negative return wire. Easiest checked by fixing multimeter pos lead to battery terminal then take negative probe to pos. points behind panel. May see a volt drop of 1 or so volts. Do similar with negative battery post to neg bus bar behind panel. Do these tests with a known load ie fridge running lights on etc. Volt drop is likely distributed through the circuit bu there may be a particular drop point. ol'will

 

[Bilgediver]

Meter on the battery says 13 volts so must be the crappy aftermarket control panel that is duff or is dropping in the the power supply to this. I have actually no idea where the source for this second panel comes from. Further investigation required.

Thanks for your help

Have you checked the earth/negative connection on the engine? I had a similar problem on a club boat. Although the outward appearance was fine when the conn3ction was disassembled it was found that ther was a problem caused by dissimilar metals. A good clean and normal service resumed.

We identified this by connecting a jump lead from the alternator bracket to battery negative and found everything was fine.

 

[KompetentKrew]

I learned recently that stainless steel is a poor conductor - that might be worth keeping an eye open for.

 

[William_H]

I learned recently that stainless steel is a poor conductor - that might be worth keeping an eye open for.

It might be a bit misleading to say stainless steel is a poor conductor. It does have more resistance than iron and a lot more than aluminium. It can be used for amp meter shunt for instance carrying all your load current but does have a volt drop. More likely KomnpetemntKrew has ahd a problem with dissimilar metal corrosion at faying surface creating resistance. ol'will

 

[KompetentKrew]

Was just going off what I remember from this video, which I cannot be arsed to rewatch right now: