Batteries depleting.

[Karen Louise]

Spending my first night on board my new home. Everything seems in order but I can't work out my battery % has dropped to 89 when I am connected to mains power. Not my area of knowledge so any help would be much appreciated : )

[Tony Brooks]

Just now, Karen Louise said:

Spending my first night on board my new home. Everything seems in order but I can't work out my battery % has dropped to 89 when I am connected to mains power. Not my area of knowledge so any help would be much appreciated : )

 

That % reading is almost certainly a lie and they may be discharged well below that. Has your shore line tripped out? There has been enough rain to get into shoreline sockets and trip the breakers on the bollard.

 

A good rule of thumb is use rested voltage to assess state of charge and tail charging current to decide when the batteries are a sfully charged as you will get them

 

Any state of charge reading on a solar controller is almost certainly a lie.

 

Study the Charging Primer that is pinned in the Maintenance section.

[Journeyman36]

There are so many possible causes and issues for this one.

 

You mention that your batteries percentage is dropping, how are you measuring/monitoring that? As a basic measurement you'll need the voltage when the batteries are at rest.

How many leisure batteries do you have and what capacity are they, as in, Ah (110Ah, 225Ah etc)

By 'connected to mains power' do you mean you switched on the inverter? Or you've plugged into a shoreline source?

As it's your new home I'm guessing you aren't very familiar with much of the setup yet, any idea on the age of the batteries? As with all things they'll have an effective lifespan - much affected by how well they were looked after. So many batteries die due to undercharging!

[Tony Brooks]

I would lay odds the batteries are badly sulphated so they do not hold much electricity and may have internal shorts, if so the shorts could blow the output fuse on the charger so they are no longer being charged. What is the voltage shown on the thing that gave you the %. Buttons may need pressing to change the display.

[Karen Louise]

I am connected to a shoreline. There are 3 leisure batteries. 

[Rob-M]

Do you have a battery charger switched on, when we first purchased our boat we initially didn't realise the previous owners had taken the battery charger so plugging in to shore power wasn't charging the batteries and 12v pumps and lights still discharged the batteries.

[Journeyman36]

3 minutes ago, Rob-M said:

Do you have a battery charger switched on, when we first purchased our boat we initially didn't realise the previous owners had taken the battery charger so plugging in to shore power wasn't charging the batteries and 12v pumps and lights still discharged the batteries.

Good point. The shoreline will of course not power any 12v fixtures on board, thereby draining the batteries.

[nicknorman]

8 minutes ago, Karen Louise said:

I am connected to a shoreline. There are 3 leisure batteries. 

Shoreline provides mains power to mains powered devices. But a lot of devices on a boat are 12v from the batteries. In order to replenish the batteries when on shore power, you need some sort of battery charger or Combi inverter charger. Think of it as bridging the divide between these two totally different types of electricity. So you need to determine what, if any, battery charging devices you have and why they are not working. Might just not be switched on / plugged in!

[blackrose]

6 hours ago, Rob-M said:

Do you have a battery charger switched on, 

 

Yes that was going to be my question. Just because the shoreline is plugged in doesn't necessarily mean the battery charger is switched on - assuming there is a battery charger. 

 

This is the first question that needs addressing before going on to look at whether any mains breakers have tripped on the boat which connect the battery charger. I think battery sulphation comes quite far down on my list of issues to be checked. Even fairly knackered batteries will power a small 12v system if a battery charger is switched on, assuming the power drawn doesn't exceed the charger output. I had an old set of knackered batteries that showed 100% just because they were on charge all the time but they were well sulphated with reduced capacity. In fact I'd say that most boats that never move sitting in marinas on shore power have knackered batteries but the owners just don't know it because they never disconnect from the mains.

Edited January 5 by blackrose

[Tony Brooks]

The last few posts are why I asked for the voltage. I agree with what has been said and expect the % reading is fictitious.

[rusty69]

It Is likely that at a bare minimum, the non mains loads will be pumps (water, waste water, bilge, toilet flush, heating ) and lights. You may also have some 12V sockets,and possibly a heating device. 

Edited January 5 by rusty69

[jonathanA]

where are you reading '89%' ?  There are a number of cheap chinese voltmeters, (often coupled with 12V car type cigar lighter sockets) that also give a 'battery charge' indication as a % (based on the voltage).   if its one of those just ignore the %age reading altogether.    

[Paul C]

3 hours ago, rusty69 said:

It Is likely that at a bare minimum, the non mains loads will be pumps (water, waste water, bilge, toilet flush, heating ) and lights. You may also have some 12V sockets,and possibly a heating device. 

If the fridge is 12V.........

[rusty69]

4 minutes ago, Paul C said:

If the fridge is 12V.........

Ah, yes. Forgot that one. Thanks.

[manxmike]

Did the OP ever respond?

[Alan de Enfield]

44 minutes ago, manxmike said:

Did the OP ever respond?

 

I think the two threads got mixed up.

 

Thank you. Have had an engineer out at considerable cost but finger's crossed am sorted.

 

 

Hi. Most of the connections were lose which isn't ideal and the settings were not configured to Lithium batteries.

Loose

 

 

[Tracy D'arth]

It sounds as though the mains connections under the Victron combi were loose as I suspected. Those terminal blocks are not the best for the currents involved. I have had quite a few burn off completely.

[blackrose]

48 minutes ago, Tracy D'arth said:

It sounds as though the mains connections under the Victron combi were loose as I suspected. Those terminal blocks are not the best for the currents involved. I have had quite a few burn off completely.

 

Are those terminal blocks part of the combi or something separate connected to it?

Edited February 23 by blackrose

[Tracy D'arth]

15 minutes ago, blackrose said:

 

Are those terminal blocks part of the combi or something separate connected to it?

They are soldered to the pcb, which is another problem, getting the screws tight without damaging the connection on the pcb. They have a solder pin, maybe 2mm, soldered in a hole a bit bigger and they get brittle fracture in the solder.

[blackrose]

Victron. Need we say more...

[Bee]

Batteries are horrible things. If only they had a lid so you could open the top and have a look to see if they were full or empty. What most of us don't realise is just how long it takes to charge a couple or three batteries. On Bee we have 2 x 110 AH batteries - or that is what they were 4 years ago, it takes 4 or 5 hours to charge them from the engine and no doubt you could squeeze a bit more in from a decent charger. We look after them and don't flatten them or they will play tricks like saying they are charged when in fact they are scrap. We now have a bit of solar (not much, just one panel of 30 watts????) and I think it is brilliant, it saves batteries from death and although it cannot power the boat it works all the daylight hours. This summer I will add another one. 

[bizzard]

A simple £4 digital volt meter wired in will tell you all you need to know about state of battery charge. But will take a little while to learn it.

[blackrose]

1 hour ago, Bee said:

We now have a bit of solar (not much, just one panel of 30 watts????) and I think it is brilliant, it saves batteries from death and although it cannot power the boat it works all the daylight hours. This summer I will add another one. 

 

I installed 2x 455w panels about 18 months ago, along with a 60 amp MPPT controller. It's one of the best installations I've done on the boat. Like everything else it took me much longer than a professional as I'm a plodder. I take advice and make sure I know what I'm doing and then bit by bit I do the installation. The main benefit is I get exactly what I want and I know how it all works. Anyway, I'm amazed at just how good it is. In summer I'm completely off grid (liveaboard), and that includes running a washing machine a couple of times/week. In winter I think it's about 50% off grid, although I've only done one full winter so I need to see what it really is over several winters. I think I spent about a grand all in so it won't take long to recoup the outlay in saved electricity payments.

Edited February 23 by blackrose

[nb Innisfree]

1 hour ago, Bee said:

Batteries are horrible things. If only they had a lid so you could open the top and have a look to see if they were full or empty. What most of us don't realise is just how long it takes to charge a couple or three batteries. On Bee we have 2 x 110 AH batteries - or that is what they were 4 years ago, it takes 4 or 5 hours to charge them from the engine and no doubt you could squeeze a bit more in from a decent charger. We look after them and don't flatten them or they will play tricks like saying they are charged when in fact they are scrap. We now have a bit of solar (not much, just one panel of 30 watts????) and I think it is brilliant, it saves batteries from death and although it cannot power the boat it works all the daylight hours. This summer I will add another one. 

A few hours to replace power used maybe, but it takes a minimum of 24hrs to fully recharge so in reality if batts are used they will never reach a full charge, at best just a slow deterioration. 

[MtB]

34 minutes ago, nb Innisfree said:

A few hours to replace power used maybe, but it takes a minimum of 24hrs to fully recharge so in reality if batts are used they will never reach a full charge, at best just a slow deterioration. 

 

Quite. 

 

ISTR reading the Trojan battery instructions and they say something to the effect of "Recharge the battery after every discharge".  Utterly impractical in the real world as putting back the top 1% of charge your fridge just took out of the batteries, takes hours.

 

And full recharging is not going to happen before the fridge needs to run again, so that instruction is rarely likely to be met on a boat in regular use, especially not a liveaboard.