EHU and charging - I've read the threads and need advice

[Grumpywhelk]

Hi all, My van has a leisure battery fed by the vans' normal charging system, with the switch to prevent overcharging etc. The problem is, in the winter with all the lights on and heater going, after a day, I need to start the van up and recharge the leisure battery as the EHU on sites merely gives me 240v power to standard 3 pin plugs fitted in the van...no charging. My plan...subject to what anyone advises is to :
Buy a bog standard trickle charger
Plug it into one of the 3 pin plugs at 240V from the EHU
On the dc side of the charger fit a male/female connector in line and this would link to + and - ring terminals on the leisure battery. i can then leave the battery end connector in situ. It sounds simple to me BUT....questions....
1. I will only charge with the van "off"...I am concerned that I will muck up the current charging system which works fine.
2. Will charging from another source (charging the leisure battery from 12v van battery whilst running and when not, charging as I've described above) muck any electrics up?
I hope that makes sense. Tim

 

[Pete C]

What you have described will work. If you are flattening the leisure battery in a day, then get a decent 10A battery charger, and make it an intelligent one that can act as a power supply, and which will keep your battery healthy.

You shouldn't have a problem if you accidentally start your van, but that depends on what the device is that charges your leisure battery from the alternator/starter battery.

Pete

 

[Grumpywhelk]

Pete, thanks very much. I am pretty sure the set up I have incorporates a relay to close when optimum charge is reached. .usually around 12.6v. I was just worried that having two charging points to the leisure battery would maybe reverse current in some way and blow something

 

[Pete C]

Yes, sounds like you have a standard relay charging mechanism. This will never be as good as a decent DC-DC charger, which is partly why your leisure battery discharges so much - it isn’t being fully charged in the first place.

Pete

 

[Bigsidavies]

I have a Victron blue smart charger wired into the 5amp feed from the 240v consumer unit. That goes to the leisure battery.
So when on EHU it charges the leisure battery (15A).
I also have a ctek dc-dc charger, but never operate the 2 together as I wouldn’t start the van if I’m on EHU.
That’s a pretty normal set up, so add something similar and you’ll be fine.
But as Pete says, sort a dc-dc charger and a decent leisure battery or you’ll never be able to survive without EHU.
Before solar I’d manage 2-3 days off grid with fridge and lights and diesel heater running etc. so something isn’t quite right.

 

[Grumpywhelk]

I have a Victron blue smart charger wired into the 5amp feed from the 240v consumer unit. That goes to the leisure battery.
So when on EHU it charges the leisure battery (15A).
I also have a ctek dc-dc charger, but never operate the 2 together as I wouldn’t start the van if I’m on EHU.
That’s a pretty normal set up, so add something similar and you’ll be fine.
But as Pete says, sort a dc-dc charger and a decent leisure battery or you’ll never be able to survive without EHU.
Before solar I’d manage 2-3 days off grid with fridge and lights and diesel heater running etc. so something isn’t quite right.

Hi, Sorry to be newbie like. so at the moment, the van battery has a system to charge the leisure battery. (relays and stuff). All works well. BUT, in winter, my plan is to have the EHU do the charging when on site. I am guessing that the Victron does that?. T

 

[Bigsidavies]

Hi, Sorry to be newbie like. so at the moment, the van battery has a system to charge the leisure battery. (relays and stuff). All works well. BUT, in winter, my plan is to have the EHU do the charging when on site. I am guessing that the Victron does that?. T

That is exactly what it does.
But if you have a system fitted already then you need to post up what you have. It may be that you already have this function.
Have you used EHU at all yet?
Also, it’s also a good idea to plug it in at home occasionally to ensure that the leisure battery is properly charged and maintained.
I always plug my EHU in at home before I go away in the van.

 

[Grumpywhelk]

Thanks so much. I've used the hook up in the UK and France. It only provides power to the 3 pin plug bank. I shall look at fitting the Victron. Cheeers, Tim

 

[jimc91]

if you buy the victron charger it comes with 2 quick attach leads, one with crocodile clips (I use this for charging a battery on a bench) and one with eyelets. Use the one with eyelets to connect to your leisure battery then buy a second eyelet lead and leave it permanently connected to the vans starter battery. This way its very quick if you need to swap your charger on to the starter battery