Battery charging

[Patrick T]

So, how often do people connect in to the mains at home to keep the battery charged ? Or is it seen as sufficient to rely on the drive to wherever you are going to do the job ? We don't use it on a daily basis so it does sit for a few days at a time.

 

[WelshGas]

So, how often do people connect in to the mains at home to keep the battery charged ? Or is it seen as sufficient to rely on the drive to wherever you are going to do the job ? We don't use it on a daily basis so it does sit for a few days at a time.

Monthly for 12 to 24 hrs As stated in handbook.

 

[AlanC]

Hi Patrick,

It all depends on how often you use the van and for how long. As it sits for only a few days, then the batteries will probably be fine and not need mains top up.

However, if you leave it parked up for a month or more, then it is wise to plug it into the mains, probably once a month, for up to 24 hours to top up all of the batteries.

When you disconnect the van, switch off the control panel. It only draws a small current but will contribute to the batteries discharge over time, if the van is not driven.

Alan

 

[Hotel California]

Hi Patrick,

It all depends on how often you use the van and for how long. As it sits for only a few days, then the batteries will probably be fine and not need mains top up.

However, if you leave it parked up for a month or more, then it is wise to plug it into the mains, probably once a month, for up to 24 hours to top up all of the batteries.

When you disconnect the van, switch off the control panel. It only draws a small current but will contribute to the batteries discharge over time, if the van is not driven.

Alan

Correction on the above :

Even if you use the Cali daily plug it in a mains 220v socket to top the lesure batts and the engine bat up to max as the alternator does not do this the full 100%
Do this on a monthly base for at least 12h in a row.

This is no must but it helps giving all the three batts. a longer life...
All the tools are in the Cali ....a simple plug in ....nothing more needed.

 

[sidepod]

Forum Search function anyone?

 

[campandfly]

switch off the control panel.

How do you do that? I thought it timed out and turned off the backlight.
Also if I was leaving my Cali for a while I would have thought the small amount of energy it used would keep the damp away.

 

[Freeley]

Press the off button not very complicated! We keep ours turned off now when not in use since we had it replaced

Sent from my Galaxy S6

 

[Alan]

What's the latest thoughts on over charging on hookup?
If that's possible!

Alan

 

[Hotel California]

What's the latest thoughts on over charging on hookup?
If that's possible!

Alan

You should think the system got a built in security that swiches things off when fully loaded?
But that is why i never just leave it plugged in at all time , as said before use a timer or plug it in each weekend , on regular base....
Thats what my VW dealer told me!

 

[2into1]

Does anyone know the 'why' behind the the assumption that the alternator can't fully charge the batteries? Is it something to do with the sophistication of the mains charger being able to do fancy things as the charge nears full (that an alternator obviously can't)?

 

[TwentyOneThirtyFive]

Mine is plugged in all the time it is on my drive and hasn't burst into flames yet. Batteries seem healthy at 4 years old.

And that's with the original 25 year old charger, I'm assuming modern chargers are even more effective.

Regarding the alternator charging, I think you are correct Peter. All you get is a bunch of amps chucked in until the VSR hits a set voltage (14.4v?) Chargers have all sorts of tricks to get more in. I keep thinking about a B2B charger instead of the split charge VSR, but can't help liking the simplicity of the relay.

 

[snowy55]

You should think the system got a built in security that swiches things off when fully loaded?
But that is why i never just leave it plugged in at all time , as said before use a timer or plug it in each weekend , on regular base....
Thats what my VW dealer told me!

When plugged in initially the central control unit will show say 5amps going into the leasure batteries then after a few hours as the batteries become charged the reading will drop to zero amps going in. This all depends on how discharged the batteries are.
Last weekend mine showed 3.8amp charge to start with this dropped to zero after 4 hours and it reminded at zero for the rest of the weekend. When looking at the ccu with the door lights on it showed 0.2 amp charge, presumably this is what the ccu and lights were using.
So yes the charger does turn itself down when it detects the batteries are fully charged, therefore avoiding over charging.

 

[Hotel California]

When plugged in initially the central control unit will show say 5amps going into the leasure batteries then after a few hours as the batteries become charged the reading will drop to zero amps going in. This all depends on how discharged the batteries are.
Last weekend mine showed 3.8amp charge to start with this dropped to zero after 4 hours and it reminded at zero for the rest of the weekend. When looking at the ccu with the door lights on it showed 0.2 amp charge, presumably this is what the ccu and lights were using.
So yes the charger does turn itself down when it detects the batteries are fully charged, therefore avoiding over charging.

Thats what one expect to get on a +50.000euro verhicle , quality equipment ....
Thanks for checking that out!

 

[AlanC]

What's the latest thoughts on over charging on hookup?
If that's possible!

Alan

No it is not possible, the mains charger is designed to measure what the state of charge is and adjust the charge current to suit. When the batteries are fully charged, the charge current will drop to just a few milliamps as a maintenance trickle charge.

So it is not possible to over charge the batteries, unless the charger has developed a fault, of course.

Alan

 

[Blackwell]

Correction on the above :

Even if you use the Cali daily plug it in a mains 220v socket to top the lesure batts and the engine bat up to max as the alternator does not do this the full 100%
Do this on a monthly base for at least 12h in a row.

This is no must but it helps giving all the three batts. a longer life...
All the tools are in the Cali ....a simple plug in ....nothing more needed.

Deffinately IS a must! Nothing kills batteries quicker than being left in any other state than 100% charge.

 

[Blackwell]

Does anyone know the 'why' behind the the assumption that the alternator can't fully charge the batteries? Is it something to do with the sophistication of the mains charger being able to do fancy things as the charge nears full (that an alternator obviously can't)?

It is fact that a standard alternator cannot fully charge a lead acid battery. This due to the crude nature of the regulator inside the alternator and the need to protect the battery from over charging. An alternator will typically have an output of 14.4 volts and a battery needs to reach an absorption voltage of 14.6 to be able to charge fully. Intelligent mains chargers can do this. You can also fit external multi stage alternator regulators to do the same, or, as stated before, a b2b charger instead of a basic split charge relay. TBH, unless you are wild camping all the time these alternatives would be cost prohibited. A regular charge from the mains is good enough.

 

[Kaydee]

Mine is plugged in all the time it is on my drive and hasn't burst into flames yet. Batteries seem healthy at 4 years old.

And that's with the original 25 year old charger, I'm assuming modern chargers are even more effective.

Regarding the alternator charging, I think you are correct Peter. All you get is a bunch of amps chucked in until the VSR hits a set voltage (14.4v?) Chargers have all sorts of tricks to get more in. I keep thinking about a B2B charger instead of the split charge VSR, but can't help liking the simplicity of the relay.

I do the same,spends its life plugged in,never had a problem and the batteries are fine at 6 years old,cant really think of a good reason not to.I only unplug it if we are away on holiday but leaving the van at home on the driveway....that doesnt happen often !

 

[Patrick T]

Ok so I get the need to have it plugged in sometime during the month, but for an electrical idiot, can someone explain the figures being shown on the panel ? Mine currently shows 14.4V & 3.6 A ? What do these represent ?? Are there maximum and minimum levels that should be achieved ?? Have studied the Cali supplement but it doesn't really explain the why's and what's .
Ta

 

[Hotel California]

Have you tried to read some older posts on battery charging ....?
There are so many treads already on how to ...how frequent ....what is...regarding battery charging ....
Just picked one using the search function....
Tree pages of reading to start with:
http://vwcaliforniaclub.com/threads/battery-maintaince-charge.9288/

 

[Kaydee]

Patrick,I can understand your interest in these things,I sadly do not.I feel it is sufficient to know that the batteries are at 100% ,now clearly if we are off hook up the leisure batteries will drain quicker and its handy to know how low they are getting.The battery icon in the bottom right corner shows the state of the leisure batteries,it will be either hook up symbol,Generator symbol ,or battery showing a % charged figure.if its on hook up it doesnt matter.if you are off hook up you might want to run the engine a bit if its low.The figures are I think indicative of the voltage the battery is putting out and the amps is the power being pulled out of it by the fridge,lights ,heater etc.As to the precise values and the importance of each,I dont really spend enough time looking at the display !

 

[AlanC]

Ok so I get the need to have it plugged in sometime during the month, but for an electrical idiot, can someone explain the figures being shown on the panel ? Mine currently shows 14.4V & 3.6 A ? What do these represent ?? Are there maximum and minimum levels that should be achieved ?? Have studied the Cali supplement but it doesn't really explain the why's and what's .
Ta

Hi Patrick,

With a voltage of 14.4 volts and a current of 3.6 amps would indicate that you are charging your batteries.

The maximum voltage will not change while on charge, staying steady at 14.4 volts. The current will slowly drop as the batteries become fully charged.

When not on charge, the voltage will start at 12volts, and slowly drop as the batteries are discharged. The current will indicate a minus number and vary depending on what is drawing current from the batteries.

Alan

 

[Patrick T]

Hi Patrick,

With a voltage of 14.4 volts and a current of 3.6 amps would indicate that you are charging your batteries.

The maximum voltage will not change while on charge, staying steady at 14.4 volts. The current will slowly drop as the batteries become fully charged.

When not on charge, the voltage will start at 12volts, and slowly drop as the batteries are discharged. The current will indicate a minus number and vary depending on what is drawing current from the batteries.

Alan

Great, that simplifies things a bit thanks Alan

 

[Californiaman]

In simple terms the 14.4 is what is in the battery (or going into the battery if on charge) and the 3.6amps is how quickly it is going in (or coming out). So, if you are 12v and 0amps, you have achieved stasis!

I think...

 

[Patrick T]

In simple terms the 14.4 is what is in the battery (or going into the battery if on charge) and the 3.6amps is how quickly it is going in (or coming out). So, if you are 12v and 0amps, you have achieved stasis!

I think...

Mmmm...... Just can't get my head around electricity, gets me every time ! Maybe I'm worrying about nothing !!

 

[AlanC]

In simple terms the 14.4 is what is in the battery (or going into the battery if on charge) and the 3.6amps is how quickly it is going in (or coming out). So, if you are 12v and 0amps, you have achieved stasis!

I think...

Not quite. The terminal voltage of a fully charged Lead Acid battery at rest, i.e. the voltage measured between the two posts, while not on charge and sitting on the bench with nothing connected to it, will be 12volts DC.

The terminal voltage of 14.4 volts DC measure across the posts, is only as a result of the charger applying this voltage to charge the battery up when connected to it.

If you have zero current being measured when on charge, then the battery is fully charged, but the terminal voltage will still be 14.4 volts because the charger is connected.

It will drop to 12 volts with no current draw, once the charger has been disconnected, then you get stasis, assuming nothing is turned on.

The important thing to remember about Lead Acid batteries, which are the type fitted to most vehicles (I say that advisedly as Hybrid vehicles do have different battery systems fitted) including the Cali, is that they must be kept fully charged at all times, if they are to have a long life. The alternator will always recharge any engine battery as soon as the engine is running. In the Cali it will also top up the leisure battery too.

If you are not using your van at this time of the year, hook it up regularly.

Alan