How long should batteries stay charged ?

[Karl]

Hi all. I replaced all 5 leisure battery’s with new 110amp 8 months ago. I’m not out on the cut as often as I would like but my question is this ! I have a wide screen 240v tv, sound bar and a 3kw Victron inverter. I have the tv on for few hours a day the 12v fridge was on all the time and 12v lights in as and when. I also leave the tv in standby  when not on and the victron on all night. When I get up in the morning the panel says 12.50v which isn’t enough to kick in the Webasto heating. Am I asking too much ? I know I should run the engine every day for an hour to give the batteries a boost. Is this right. When i’m not out I live aboard with mains hook up. Thanks.

[Alan de Enfield]

6 minutes ago, Karl said:

Am I asking too much ? I know I should run the engine every day for an hour to give the batteries a boost.

You will destroy the batteries very very quickly.

 

You should run the engine 3 hours per day and 8 hours at weekends.

 

 

[Keith M]

12.5 should be enough to start the heater 

I wonder if there is significant volt-drop on the cable suppling the heater?

[BEngo]

Your question has been answered on here a lot.  Have a search.  It is quite good these days.

Then:

 

Please read the battery charging primer.

Please do a power audit.

Summary:Your batteries are probably knackered.

 

You should charge your batteries as full as you can every day, and to really really full at least once a week.  If you do the batteries may last a couple of years .  If not they will last maybe a year. 

 

Some solar will help with the charging, and will pay for itself very quickly.

 

N

  

[mrsmelly]

It's a wind up. 

[WotEver]

18 minutes ago, Karl said:

Am I asking too much ?

Yeah.

[Alan de Enfield]

8 minutes ago, Keith M said:

12.5 should be enough to start the heater 

I wonder if there is significant volt-drop on the cable suppling the heater?

I'll be betting the batteries have lost a large percentage of their capacity and when the heater trys to kick in it drags the voltage down to 11'ish

[Tony Brooks]

10 minutes ago, Keith M said:

12.5 should be enough to start the heater 

I wonder if there is significant volt-drop on the cable suppling the heater?

That was my first thought - closely followed by "why would anyone running off limited batteries leave the inverter running all night plus the TV on standby".

 

12.5 V first thing should not be an issue as far as the batteries are concerned. That is about 3/4 charged but far more importunately for the OPs battery management it should be considered  half charged.

 

Alan may be correct but with the inverter and TV on all night so 12.5 is not the rested voltage I rather doubt he is.

Edited April 23, 2020 by Tony Brooks

[bizzard]

Get a small cheap 14' telly for when your not on the mains and don't leave it on standby. Fridges can be switched off at night during the winter. I turn mine on at about 11am and off again at about 11pm, and bundle my grub into my bottomless box out on the cold steel fore deck for the night. It's still pretty cold at night here.  Its a gas fridge you see  it's the extra lark of humping about gas bottles, not the cost

[OldGoat]

There's no mention of a battery charger (is the Victron a combi) - but the OP says he's in a marina.

I'm wondering whether he thinks solar in the winter is good enough - 'cos it isn't...

[Alan de Enfield]

2 minutes ago, OldGoat said:

There's no mention of a battery charger (is the Victron a combi) - but the OP says he's in a marina.

I'm wondering whether he thinks solar in the winter is good enough - 'cos it isn't...

I'm reading as "when in the marina no problem as I'm on the mains. but, when out cruising the voltage is too low to start the heater, I know I 'should' run the engine for an hour every  day"

[OldGoat]

4 minutes ago, Alan de Enfield said:

I'm reading as "when in the marina no problem as I'm on the mains. but, when out cruising the voltage is too low to start the heater, I know I 'should' run the engine for an hour every  day"

I'm obliged M'lud....

Foolishly I assumed he would be in a marina at the moment as he should not be cruising - but then there's mention of 'running the engone for an hour a day' which wouldn't be needed if he had a shore supply AND a battery charger.

 

As often happens there's insufficient joined up information....

[cuthound]

2 hours ago, Alan de Enfield said:

I'm reading as "when in the marina no problem as I'm on the mains. but, when out cruising the voltage is too low to start the heater, I know I 'should' run the engine for an hour every  day"

 

But if he is cruising, then the engine should be running and charging the battery as he goes along the cut.

 

I usually cruise 5-6 hours a day when out cruising, with the charger connected to a shoreline when at my home mooring and have not had any battery problems. Indeed my current set of high quality  Lifeline AGMs are over 12 years old (however I dont live aboard but cruise about 500 hours a year).

[Alan de Enfield]

1 hour ago, cuthound said:

 

But if he is cruising, then the engine should be running and charging the battery as he goes along the cut.

 

I usually cruise 5-6 hours a day when out cruising, with the charger connected to a shoreline when at my home mooring and have not had any battery problems. Indeed my current set of high quality  Lifeline AGMs are over 12 years old (however I dont live aboard but cruise about 500 hours a year).

My 'mistyke' - he does not say "cruising", he actually says 'when out on the cut' (maybe he goes and 'parks up' for a few days, hence the battery voltage dropping)

[cuthound]

17 minutes ago, Alan de Enfield said:

My 'mistyke' - he does not say "cruising", he actually says 'when out on the cut' (maybe he goes and 'parks up' for a few days, hence the battery voltage dropping)

 

Must be either that or a defective alternator. ?

[Bee]

In a nutshell the only time you can have a big telly and a fridge and all the other stuff that brochures say you can is in a house.  Back in the good old days many engines came with a hand start, lights were paraffin, the tv if there was one was a little black and white thing and after a few hours the tv picture would shrink. Since those times we now have alternators, solar and 10 times the electrical gadgets but most batteries are still much the same, they last about 3 years at best and need to be treated like precious jewels, spoken to politely, polished and kept warm and dry and only ever used for short periods.

[Col_T]

Quote

and only ever used for short periods.

and then charged for longer periods!

[Tony Brooks]

I still don't see any evidence that this is a lack of charge problem. 12.5 volts with the inverter standby load and TV standby load is still a well charged battery. the fact that the Webasto will not start at 12.5V  seems far more likely to be a volt drop problem - or the OP is not telling the truth. What have I missed?

 

I don't know the values but I am sure NMEA does. Could this be an automotive spec heater? They cut out at a higher voltage than marine units.

Edited April 23, 2020 by Tony Brooks