Leisure battery drain. Could a relay cause it? Or other issues

[j4ckal]

OK, this could end up a little long winded...
I have a 110(iirc)a/h leisure battery charged by a ctek ds250e going to a 12 way fuse box. It feeds, fridge permanent 12v, tap/in tank pump, ceiling lights, map reading lights, usb's, cig lighters.

I rewired my leisure electrics this year to add a main leisure battery cut off (via a heavy duty 200a relay) so i can fully disconnect it. I also added some small relays for the tap, shower pump and a fridge temperature controller (the fridge compressor main 12v feed is still direct from the fuse box, no switch).
These are now controlled by small rocker switches mounted in the overhead cubby hole, adjacent to which I've added a permanently live 12v led voltage readout/display.
The switch feeds (for the coils, ie. Pins 85/86) for the small relays are taken from the 12 way fusebox and the main heavy duty cut off relay switch feed is straight off the leisure battery with an oinline fuse.
Straight after the main relay I also added a maxi blade fuse box (that then feeds the existing 12 way fuse box and ctek) and also added an earth busbar - so I don't have to connect everything to the battery ie. just one main (+) and one main (-) coming off the batt terminals.

Before I did this I had no way of turning the leisure electrics off and mutliple wires coming off the battery terminals so it seemed a logical way to do it....

Prior to this work I'm sure the leisure battery would hold charge indefinitely, ie. 12.8 - 12.9v pretty much constant, so I'm guessing its something I've changed.

The voltage now seems to drop over a few days, I haven't used the van for a good 5 days and it is down at 12.1 volts, this is with nothing switched/running. If I isolate the leisure battery via the main relay then it will hold its charge, ie. when switched back on it will be around 12.8/12.9 volts no matter how long it has stood. The relay cuts the leisure battery off completely, i.e from the ctek as well.

-What is the current draw from the coil on the main relay? 12v planets relay guide suggests 150-200mA? (Should I have wired the relay as as NC ie. used a 5 pin relay so that the coil isn't drawing current all the time whilst the leisure battery is on?)
-The 12v led voltmeter, would this draw much current/mA? I am going to change this so it can be switched on or off, probably via a momentary switch, as its too bright at night whilst trying to sleep and I really only need ro check voltage occasionally.

If neither of those are causing that level of battery drain then I guess I have other issues. I can measure the current drain at the battery and pull fuses until it drops to isolate which circuit it is on?

Any advice welcome and if a diagram is needed I will try and get one drawn up, I have a very rough one somewhere in the garage.

Cheers.

 

[Pete C]

If the relay is energised “permanently“ and is drawing 150mA, then that would discharge the battery and drop the voltage as you describe, but I think we need to see a diagram.
The LED voltmeter will draw a lot less current. I have one too, but it is wired to a momentary switch as you describe.

Pete

 

[j4ckal]

If the relay is energised “permanently“ and is drawing 150mA, then that would discharge the battery and drop the voltage as you describe, but I think we need to see a diagram.
The LED voltmeter will draw a lot less current. I have one too, but it is wired to a momentary switch as you describe.

Pete

Cheers Pete.
My circuit diagram drawing skills aren't up to much but will try later.

Yes, the main heavy duty relay is energised permanently, ie. 12v feed going to the coil to switch leisure battery 'on'. Is that not the correct way?

Its wired as follows;

Batt>inline mega fuse>HD relay>midi blade fusebox

The 4 way midi blade fuse box then supplies the 12 way standard blade fuse box (for lights, usbs, shower pump, tap pump, cig, fridge etc) and ctek.

100a earth busbar is connected to chassis and negative post on leisure battery. This is also connected to the 12 way fuse box as it has its own negative busbar for the lights, usbs etc.

Does all that sound correct?

Cheers.

 

[Pete C]

I’m not 100% sure why you need a relay to disconnect the leisure battery.

What I did was run 2 maxi fuses off the leisure battery - one for the fridge, and one for everything else (it goes to a fuse box of smaller fuses). I put the 2 maxi fuses where they were accessible, so I could easily pull them out to isolate everything from the leisure battery. In reality, I have only needed to pull them out when working on the leisure electrics, even when leaving the vehicle for weeks.

Back to your situation. If you are going to leave the vehicle for some time, and you want to isolate the leisure battery with the relay, then you need to wire it so it isn’t drawing current. It should be energised, and connecting the leisure battery, when you have something charging the leisure battery, like solar, your alternator, or a hook-up.
One final point - an energised relay is a potential fire risk as you are passing current through a coil of wire for a considerable period when the vehicle could be unattended.

Pete

 

[j4ckal]

Cheers Pete.

I just thought it seemed a good idea to be able to disconnect the leisure system at the flick of a switch, for maintenance or when leaving the van parked up. Like yourself though, in reality, I dont really use it.
I may swap the relay out for an actual battery cut off switch something like so (or it means making new battery cables up);

 

[scotia]

hello, older thread but @Pete C & @j4ckal do you have any pics of your install? im re-doing my under the seat mess and trying to work it into something neat. I'd like to include a switch for my leisure electrics (just usb, lights and 12v sockets) and i'd like inspiration if possible..

at the moment i have 1 cable from each batt post but my maxi/midi fusebox only has 4 positive outlets and im stuck..

 

[Dellmassive]

hello, older thread but @Pete C & @j4ckal do you have any pics of your install? im re-doing my under the seat mess and trying to work it into something neat. I'd like to include a switch for my leisure electrics (just usb, lights and 12v sockets) and i'd like inspiration if possible..

at the moment i have 1 cable from each batt post but my maxi/midi fusebox only has 4 positive outlets and im stuck..

Got a few pics of your setup?

 

[drinfinity]

I’m planning latching relays for lights and high power chargers. This will reduce the load for the coils, and also make it easier to have multiple light switches.

 

[Pete C]

Under my drivers seat I have just a battery, a DC-DC charger and 2 fuses, both accessible without removing the seat.

Just bear in mind that the more you put under there, the more that could go wrong, leaving you having to remove the seat to (say) change a small fuse.

Pete

 

[scotia]

@Pete C i totally agree - I've had up till now everything available fuse wise from either the front or the back of the seat.
@Dellmassive here are a couple of shots.

basically i have a victron solar mppt (not shown) and victron shunt that i'd like to house on a central board close to the battery i think, similar to one of your previous setups.
at the front of the seatbase i have a 4 way +ve with common -ve (i saw the same thing in your pics on the other thread). I feed the battery +ve into this and then supply my 12v lights and usbs/12v at the rear. I also come in with the solar and a victron charger which is under the other seat.

What i'd like to do is power a dometic fridge for which i need to use at least 10mm2 (why is there nothing between 10mm and 16mm?!) as the run goes to the back of the lwb, and to an outside anderson socket at the back of our sliding door (for when we camp we would like to remove the fridge.)

This means that I've run out of +ve supplies on my fusebox, but i really want to isolate my 12v usb/12v socket panel at the back of the seat...

any tips?

thanks a million.

edit - i have the battery covered with the vw rubber boot so the terminals are normally protected.

edit 2 - so i have 6 sockets - 2 usbs of 2x 2.1, 2 usbs 2.4 and 1.2 and then the 2x12v sockets.
the leisure battery (110Ah AGM) is currently fused to 50A. Solar panel 250W swaytronic.

 

[scotia]

@Dellmassive would this be any good (coupled with a std negative busbar) 7 Way MIDI Fuse Box

 

[Dellmassive]

Possibly....

But have a look at this thread, and the parts list further down it ..

You may see something more suitable...

12v Lithium Leisure Battery Box 138Ah 1766Wh -- How I Done It --

12v Lithium Leisure Battery Box 138Ah 1766Wh -- How I Done It -- It's about time that I got this long-overdue project sorted out. The missing parts are on order and completion is in sight . . . . . . . . ready for the Post Pandemic 2020 Camping Trips (Hopefully) This is where it started. p1...

www.t6forum.com

Like this?

 

[scotia]

Possibly....

But have a look at this thread, and the parts list further down it ..

You may see something more suitable...

12v Lithium Leisure Battery Box 138Ah 1766Wh -- How I Done It --

12v Lithium Leisure Battery Box 138Ah 1766Wh -- How I Done It -- It's about time that I got this long-overdue project sorted out. The missing parts are on order and completion is in sight . . . . . . . . ready for the Post Pandemic 2020 Camping Trips (Hopefully) This is where it started. p1...

www.t6forum.com

Like this?

View attachment 170044

yep thats the guy i have at the front of the seatbase - thats where my battery feeds into. But i need a couple more inputs thats why i was looking at the 7way one?

 

[Dellmassive]

Gotcha.

Yes you can fit the 7way one.

Or just fit a second fuse box next to your existing one.

Midi fuses are normally for big power items.

I show four different fuse boxes in that thread.

 

[scotia]

Ok - or can I take another positive cable out of that 4way fusebox (opposite the positive input) I have to feed another midi 3or4 way for the fridge? Or is it best to have two separate feeds from battery to seperate fuse boxes?
And to install a switch for my "leisure" stuff - can I just use a battery kill switch on the positive input to my blade fusebox at the back of my seat?

 

[Dellmassive]

Yes you link fusebox es,

Provided the main cable and fuse from the battery to the first fusebox is fat enough to take the entire load of both fuse boxes and kit.

If not, either upgrade that cable and fuse, or run the second fusebox back to the battery via a separate cable and fuse.

Yes you can fit a kill switch on any of the POS lines, to shut off any loads down stream of that switch.