Fluttering battery voltage.

[ronnietucker]

This just started happening today.

 

I'm on shore power and every 5 or 10 minutes the battery voltage will drop from about 14.7 down to about 10 or 11 then jump back up again. All within a second/two.

 

It's noticeable enough to make the led lights flicker, but it's not showing anything on the victron panel thing I have.

 

Usually if I don't have incoming power or I'm using too much power it'll show in lights on the victron panel.

 

Video of it happening: https://photos.app.goo.gl/6MYaCjcXw6ie2ARE8

 

I've checked the power cable coming into the boat and it's definitely live.

 

Any ideas?

[fatmanblue]

Any heavy loads applied?

 

What happens if you disconnect the shore power?

 

I'd be checking battery voltages (disconnected from the charger) for failing/failed cells. The charger may partially or fully mask this, boiling the other cells in the process.

[MtB]

7 hours ago, ronnietucker said:

I'm on shore power and every 5 or 10 minutes the battery voltage will drop from about 14.7 down to about 10 or 11 then jump back up again. All within a second/two.

 

 

Sounds to me like a bad connection.

 

How are you measuring "battery voltage"? I bet you don't have the points of two DVM probes pressed into the lead of the battery terminals, so you are probably not actually measuring battery voltage. You are probably seeing the system voltage some way away from the batteries, beyond a dodgy or high resistance connection somewhere.

[cuthound]

9 hours ago, MtB said:

 

 

Sounds to me like a bad connection.

 

How are you measuring "battery voltage"? I bet you don't have the points of two DVM probes pressed into the lead of the battery terminals, so you are probably not actually measuring battery voltage. You are probably seeing the system voltage some way away from the batteries, beyond a dodgy or high resistance connection somewhere.

 

I agree. I can't think of any other fault that would cause this.

[Tracy D'arth]

16 hours ago, ronnietucker said:

This just started happening today.

 

I'm on shore power and every 5 or 10 minutes the battery voltage will drop from about 14.7 down to about 10 or 11 then jump back up again. All within a second/two.

 

It's noticeable enough to make the led lights flicker, but it's not showing anything on the victron panel thing I have.

 

Usually if I don't have incoming power or I'm using too much power it'll show in lights on the victron panel.

 

Video of it happening: https://photos.app.goo.gl/6MYaCjcXw6ie2ARE8

 

I've checked the power cable coming into the boat and it's definitely live.

 

Any ideas?

Fridge cutting in?

[ronnietucker]

It seems it was the death throes of my victron inverter/charger. 

 

Pulled out the shore power and everything went dead. Plugged shore power back in again and nothing. No lights on the victron unit or the control panel.

 

Spoke with victron, they agree and say it sounds like the board is gone. Same diagnosis from a local victron dealer.

 

Oh well, time to try and get a new victron fitted ☹️

 

Getting some leccy using a 4-way adapter to the shore power bollard.

 

Ah the joys of boating.... 😄

[ronnietucker]

update update (so good they named it twice): not only the Victron but the isolation switch was goosed too.

[MtB]

2 hours ago, ronnietucker said:

update update (so good they named it twice): not only the Victron but the isolation switch was goosed too.

 

 

Hmmm. 

 

Are you sure it wasn't just the isolation switch?