Battery and electrics explained

[Voodoo_Pirate]

Good morning,

New to the forum and new to owning a new to me T6.1 camper.

Please go lightly, but could someone clarify the battery and electrics situation in the most simplest terms.

I ‘think’ it works like so…. I have a Rayne automotive EHU point which feeds the Rayne automotive 8A mains charger which charges the leisure battery when plugged in.

I have a CTEK250se DC-DC charger which uses the alternator to charge the leisure battery while driving once after also topping up the starter battery?

Now I get that plugging in via EHU on camp site or driveway etc is going to power the van and charge the leisure battery.

And by fitting a Noco Genius charger this would effectively trickle charge the starter battery from the leisure battery when the van is plugged in via EHU?

I probably have this all completely wrong. Just trying to get my head around what is what and how it all works so after the first trip away I don’t end up with flat battery’s!

Thank you!

 

[Ninj43]

Welcome! There are obviously many ways to wire up a system and without seeing what's going on with yours it's a bit of a guess, but in general:

I ‘think’ it works like so…. I have a Rayne automotive EHU point which feeds the Rayne automotive 8A mains charger which charges the leisure battery when plugged in.

Yep

I have a CTEK250se DC-DC charger which uses the alternator to charge the leisure battery while driving once after also topping up the starter battery?

Usually just the leisure battery

Now I get that plugging in via EHU on camp site or driveway etc is going to power the van and charge the leisure battery.

Yep

And by fitting a Noco Genius charger this would effectively trickle charge the starter battery from the leisure battery when the van is plugged in via EHU?

Will charge whatever you connect it to, but not usually the starter battery via the leisure battery. You've got your Rayne charger doing your leisure battery, so the Noco would be better used to trickle the starter battery if you're not driving the van much

 

[Voodoo_Pirate]

Welcome! There are obviously many ways to wire up a system and without seeing what's going on with yours it's a bit of a guess, but in general:


Yep


Usually just the leisure battery


Yep


Will charge whatever you connect it to, but not usually the starter battery via the leisure battery. You've got your Rayne charger doing your leisure battery, so the Noco would be better used to trickle the starter battery if you're not driving the van much

Thanks Ninj43! Big help!

The thinking around the Noco or similar would be more for when on camp sites etc not wanting the battery to be dead after 2/3 days as from what Iv read the starter battery can drain quite quickly from the opening/unlocking of doors etc.

The van also won’t move much as it’s purely for trips away!

Or is there a better way to constantly keep the starter battery also topped up while idle but plugged into EHU?

 

[step]

Ablemail AMT12-2 Battery Maintainer is the usual go to trickle charger. Fit and forget and the starter battery gets topped up from leisure in small amounts when needed

Ablemail AMT12-2 Battery Maintainer

<p><span style="font-family:arial,helvetica,sans-serif;"><span style="font-size:14px;"><strong>Article No. AMT12-2</strong></span></span></p> <p...

www.roadpro.co.uk

 

[Voodoo_Pirate]

Ablemail AMT12-2 Battery Maintainer is the usual go to trickle charger. Fit and forget and the starter battery gets topped up from leisure in small amounts when needed

Ablemail AMT12-2 Battery Maintainer

<p><span style="font-family:arial,helvetica,sans-serif;"><span style="font-size:14px;"><strong>Article No. AMT12-2</strong></span></span></p> <p...

www.roadpro.co.uk

Cheers step,

Does this work when the van is plugged in via EHU? Or also when completely idle not plugged in at all? Or both?

Also, people who have these fitted, where is the best/most likely place to fit?

I’m starting to learn quickly there is a fair few variations of what people have set up wise in their vans!

 

[Anakin]

The Ablemail is just between the leisure battery and the starter battery, it’s nothing to do with the EHU. It trickle charges the starter battery, if the leisure battery is in good health. It’s useful as most systems focus on topping up the leisure battery (solar for example) and your obviously in trouble if you flatten the starter battery when camping. It’s a tiny unit that sits close to the leisure battery (for example under the drivers seat) and only needs a few small wires to connect, as it carries low current.

Cheers step,

Does this work when the van is plugged in via EHU? Or also when completely idle not plugged in at all? Or both?

Also, people who have these fitted, where is the best/most likely place to fit?

I’m starting to learn quickly there is a fair few variations of what people have set up wise in their vans!

 

[Voodoo_Pirate]

If it trickle charges the starter battery from the leisure battery will this not risk running the leisure battery flat when sitting idle?

 

[Anakin]

It has a cutoff value, so only tops up the SB if the leisure battery is above a certain voltage. For example, my LB is topped up with solar, so the Ablemail then keeps the SB trickle charged when the LB is in a healthy state.

 

[Voodoo_Pirate]

ok this makes sense. How and when would this trickle charge take place if I don’t have solar? When I’m plug in via EHU?

Side note…. How much of a ball ache is it upgrading from AGM battery to lithium? I believe my current smart charger will also need upgrading from an 8a charger to a 10a charger.

 

[Ninj43]

If you're plugged into EHU and from it are charging the leisure battery with your Rayne charger, the Ablemail will offer a very gentle trickle to help make sure you don't flatten your starter battery.

Charger needs to be compatible with Lithium although most are. Charge current depends on the size of the lithium and how much you're expecting to be pulling out of it.
If everything is 12v and you are using the EHU just to to replenish the battery you need more juice. If however you are just running say the fridge on 12v and and the odd light, everything else on 240v, you don't need so much charge.