Leisure battery charging

[Topsy]

My GC leisure battery was showing 12.1 v this morning so I have run the engine on idle with the dashboard switch on for boast charge and the control panel is showing the battery as charging but after an hour the battery voltage has no changed (still showing 12.1v). I don’t have any solar. My previous GC would charge up the battery in this time. Any suggestions?

 

[GordonH]

1 is the 12.1V the reading from the control panel ?
2. What does the current (A) figure say ?
3. Is the battery state of charge % increasing and what is the number ?

 

[Topsy]

1 is the 12.1V the reading from the control panel ?
2. What does the current (A) figure say ?
3. Is the battery state of charge % increasing and what is the number ?

1. Yes the 12.1 v reading is from the control panel.
2.the current figure is -1 ( but when the fridge kicks in it goes up to -6).
3. The battery state of charge is 40% (although I was told by a dealer technician that is not always an accurate reading).

 

[GordonH]

If the current (A) is reading negative then the battery is discharging. Is the engine still running?

(Note : I have always found the the SOC % to be accurate, I have wired in a Victron shunt on my GC leisure battery as a comparison as when I first had my van I heard similar statements on the forums. I have found the control panel % always in close agreement with the Victron. I think these accuracy queries may be down to a misunderstanding around how state of charge is measured and how battery voltage is related to the state of charge. Voltage is not a particularly good measure of an AGM batteries state of charge unless the battery is and has been at rest for a period of time eg not charging or discharging. What is often a bit non sensical on the control panel is the hours remaining figure as it appears to use a very short time averaging period for the calculation)

 

[Topsy]

Sorry the ampage reading I gave of -1A was after I had turned the engine off. When I am running the engine and have the dashboard boost button on then the control panel is showing +111A

 

[Topsy]

Sorry the ampage reading I gave of -1A was after I had turned the engine off. When I am running the engine and have the dashboard boost button on then the control panel is showing +111A

Also the act Voltage reading is showing 14.1v when the engine is running and the boost button is on (it all appears to show it’s charging but when I switch off the engine the reading is still 12.1v)

 

[GordonH]

Sounds like plenty of charge going into the battery. How old is the battery and when was the last time you charged it?