OK to leave leisure battery on permanent trickle charge between trips?
- Thread starter Sooty6.1
- Start date
I did the exactly the same thing as you have EHU then Ctec internally via 12v lower dash socket. Installed BM2 this afternoon onto a starter battery and it gave me a reading of 12.1, I thought wth? Victron powers leisure battery and it was on 13.2v float. So it appears that this method didn't do anything for my starter battery despite Ctek charger showing the complete cycle and it was on float (cycle 7). What's going on on my end then?
That sounds a bit convoluted @moomin-j
The ablemail is fed directly from my starter battery... its DC-DC.... so excess power from the starter battery is fed to it and used for charging the leisure batteries when needed...
But its smart enough to know not to drain the starter battery.... as it needs a high enough trigger voltage
If you look at the flashing LED on the ablemail it shows that when the starter battery has the charger connected (and starter battery is charged) the Ablemail LED indicates leisure batteries are charging (flashes green..) and my BM2's on leisure batteries are around 13.4V with very little current draw (just LED lighting on) not measured with the fridge on.... so would expect similar voltage drop to you with the fridge on...
When the starter battery is low and taking charge onboard the ablemail LED flashes amber indicating its not absorbing any charge...
Try yours and let me know if its the same....
Aha, will do in the morning. This is showing now as its charging via clamps directly into the battery.
Its the same principle as when you drive the van the alternator charges the battery which in turn charges your leisure batteries... but instead of the alternator putting the charge in its your mains charger in this case....
Clearly if your drawing excessive current then the EHU is a better option but if your just on standby and parked up keeping things topped up then its an easier solution.
Cheers - good explanation, I never really thought about it that way.
In the summer months it's probably easier to do it your way with little draw and solar keeping the leisure side of things topped up, but at the mo, I have a 240v radiator in Buster, keeping all things toasty so the EHU is, unfortunately needed, that will then give me the necessary 240v inside to plug into.
So looking from the front is this the bolt just underneath the battery. If it is the same bolt as I marked it on my photo, someone on the forum told me before not to attach anything on it?
Yes @EdH - Thats the one i use..... Some people will say its not an official VW OEM earthing point....
But then the one something is attached to with the yellow arrow below isn't either....?
However both points have the same ground potential..... so providing there is good contact through to the vehicle body will provide a good earth....
In your case I would say the one with the yellow arrow is worse unless you have removed some of the paint to make a better contact to the vehicle chassis.
But then the one something is attached to with the yellow arrow below isn't either....?
However both points have the same ground potential..... so providing there is good contact through to the vehicle body will provide a good earth....
In your case I would say the one with the yellow arrow is worse unless you have removed some of the paint to make a better contact to the vehicle chassis.
To be honest I haven't removed any paint from the headlamp bracket. Checked the bolt with voltmeter and its giving the ground. Auxiliary light earth connected there as you can see that little black cable, and I also attached BM2 there as well. Shame VW didn't place a decent earth clamp point close by. My friends brand new Seat Cupra has a large earth clamp point just below the wiper tray with a bolt as well.
@EdH - Everyone has there own method to be honest.... So long as its ground potential and a good contact you should be fine... If you wanted you could quite easily extend a proper earthing lead from the engine block earth point or similar....
Have a look at this thread which may be useful... https://www.t6forum.com/threads/battery-charging-main-battery-earth-point.10185/
Have a look at this thread which may be useful... https://www.t6forum.com/threads/battery-charging-main-battery-earth-point.10185/
@JasonW
I popped this question to the converter of our van.
Can you please let me know which 12v socket is powered solely by a starter battery and which one(s) is/are powered by a leisure battery? There are three 12v sockets in our van (one on upper dash and one on lower dash next to the gearstick, and 3rd in a little cupboard next to the sink). They all appear to be permanently live and I am not sure which ones are using which battery.
The reason for the question is that I attempted to charge/maintain the starter battery via 12v socket (van is currently plugged in via EHU to top up the leisure battery), I plugged my Ctec maintenance charger (connected via mains socket from inside the van) into lower dash 12v socket but it appears that it didn't charge the starter battery at all despite the charger showing that full charge is completed and it was on float program. It's a brand new smart charger (Ctek 3.8a) which works fine as tested on our Golf.
Van is not used at the moment and the starter battery is on the low side, so I was attempting to maintain both batteries at the same time via this method (EHU would charge leisure battery and internal mains socket via Ctek charger through 12v lower dash would maintain the starter battery).
So, I am trying to ascertain if the lower dash 12v socket is connected to the starter battery or not, as it was strange to note that the charger indicated full charge while the battery was quite low and indicated 12.0v when I tested it directly on a starter battery with a multimeter.
The Leisure battery was fully charged via Victron installed charger which showed 13.2v and on float.
Can you also confirm if the leisure battery was a factory installed?
They just provided the answer:
If it has under-seat battery then its a factory fitted item and the 12v socket on the top of the dash and the 12v socket in the cupboard are both fed from there (leisure battery) and are both permanently live.
The one on the front lower part of the dash is fed from the vehicle battery and is not permanently live, it’s ignition fed.
The customer won’t be able to maintain the vehicle battery using the 12v sockets, it’s recommended to connect directly to the battery itself.
so, it appears that the lower 12v is starter battery connection, but then how come 12v usb/voltmeter is always lit-up when I was checking the battery level and the van is locked? Does the above answer make sense to you?
I popped this question to the converter of our van.
Can you please let me know which 12v socket is powered solely by a starter battery and which one(s) is/are powered by a leisure battery? There are three 12v sockets in our van (one on upper dash and one on lower dash next to the gearstick, and 3rd in a little cupboard next to the sink). They all appear to be permanently live and I am not sure which ones are using which battery.
The reason for the question is that I attempted to charge/maintain the starter battery via 12v socket (van is currently plugged in via EHU to top up the leisure battery), I plugged my Ctec maintenance charger (connected via mains socket from inside the van) into lower dash 12v socket but it appears that it didn't charge the starter battery at all despite the charger showing that full charge is completed and it was on float program. It's a brand new smart charger (Ctek 3.8a) which works fine as tested on our Golf.
Van is not used at the moment and the starter battery is on the low side, so I was attempting to maintain both batteries at the same time via this method (EHU would charge leisure battery and internal mains socket via Ctek charger through 12v lower dash would maintain the starter battery).
So, I am trying to ascertain if the lower dash 12v socket is connected to the starter battery or not, as it was strange to note that the charger indicated full charge while the battery was quite low and indicated 12.0v when I tested it directly on a starter battery with a multimeter.
The Leisure battery was fully charged via Victron installed charger which showed 13.2v and on float.
Can you also confirm if the leisure battery was a factory installed?
They just provided the answer:
If it has under-seat battery then its a factory fitted item and the 12v socket on the top of the dash and the 12v socket in the cupboard are both fed from there (leisure battery) and are both permanently live.
The one on the front lower part of the dash is fed from the vehicle battery and is not permanently live, it’s ignition fed.
The customer won’t be able to maintain the vehicle battery using the 12v sockets, it’s recommended to connect directly to the battery itself.
so, it appears that the lower 12v is starter battery connection, but then how come 12v usb/voltmeter is always lit-up when I was checking the battery level and the van is locked? Does the above answer make sense to you?
The 12v socket on our panel van is permanently live. The one in the dash is ignition fed.
On some VAG vehicles, ignition fed 12v sockets and USB outlets can go live when the car is unlocked, and stay live for some time until after they are locked - could this be the case with yours ? It might explain what you are seeing.
Pete
On some VAG vehicles, ignition fed 12v sockets and USB outlets can go live when the car is unlocked, and stay live for some time until after they are locked - could this be the case with yours ? It might explain what you are seeing.
Pete
That seems a bit vague from the converters @EdH
So I assume you have your BM2 connected to the starter battery now....
Did it start charging when you connected the CTEK to the other 12V socket... like we discussed..?
You may need to go through each 12V socket in turn and see which one makes your Starter battery BM2 react and show a positive change in charge.
It could be as Pete says and the socket is only live for a short period after the car is locked again....
But you need to leave it connected overnight and see what affect its having through each 12V socket
So I assume you have your BM2 connected to the starter battery now....
Did it start charging when you connected the CTEK to the other 12V socket... like we discussed..?
You may need to go through each 12V socket in turn and see which one makes your Starter battery BM2 react and show a positive change in charge.
It could be as Pete says and the socket is only live for a short period after the car is locked again....
But you need to leave it connected overnight and see what affect its having through each 12V socket
The usb would be indicating voltage level in the morning without me not unlocking the van whole of the night, which leads me to believe that this 12v socket is permanently live.
Ha, I attempted that but the charger already charged the starter battery (via clamps) to the 100% percent so the BM2 did not then sense additional charge. The same thing happened with the rest of the sockets (top dash and one in small cupboard, which are apparently connected to the leisure, which is also full by being charged with Victron in-built charger through the EHU). Starter has now dropped to 98% since last Sunday when the charge was completed. So I might be in position to test your method.
What added to the confusion was that the Ctek charger was showing completed proces of charging after 24hrs via 12v lower socket and then measure via multimeter indicated much lower voltage. Hence for days I thought that the charger maintained the battery on float (lights indicating this) but it wasn't the case.
Haven't run the van since last Sunday. It has been connected to the EHU and still connected. Currently all 3 12v plugs indicating the same voltage via usb thingy showing 13.4v.
BM2 didnt flinch when I plugged the charger into lower and upper dash 12v. Strange.
Now connected via permanent ctek dongle thingy like yours directly to the battery and BM2 has indicated the charge. None of 12v sockets haven't noticed the charging and have remained on 13.4v. Hmmmm, this almost looks like that the ehu is trickling some voltage into the lower dashboard 12v through the leisure battery hence it's not registered any power from the ctek charger.
Well strange, it's such a shame that this method of charging is not working for my van, as it would be well handy to charge the both batteries at the same time.
