Charging Main Battery from EHU?

[hoggle]

Hi folks, I'm hoping someone on here will be able to answer a question that i have. I spent the night in Aviemore last night, and the Van wouldn't start this morning. The main Battery had drained and there wasn't enough charge to start it. I got a jump start from a fellow Camper and made it home ok.
So, first of all. I hardly use the Van and the journey down to Aviemore is around 30 miles. So It's quite possible that the main Battery isn't getting charged properly.
I have a Victron blue smart charger to charge the leisure from EHU. I know It's function is it charge the leisure battery, but does it also charge the main battery too when It's connected to the EHU?
I also have a CtekD250SA Dc-Dc charger fitted between the Two batteries.

 

[Deaky]

Your charger will only charge the leisure battery on EHU. I wouldn’t expect the starter to be flat though. What type is your stater battery. AGM or MOLL?

 

[t0mb0]

A lot of people use a ‘Battery Master’ type trickle charger to keep the vehicle battery topped up from EHU/solar. Only about £25 usually. Some b2b or solar chargers have these built in.

 

[hoggle]

Hi Deaky, it's a Varta AGM.

 

[Dellmassive]

NO, as @Deaky mentioned.

the CTEK only reverse charges the starter from the Solar side :

The DC-DC only charges starter>Leisure . . .

The EHU only charges the Leisure . . . . . .

SO. . . . . . . .



D250SA

you could use a Diode based reverse charge box "standby charger" ( as @t0mb0 mentioned) like this: https://amzn.to/2v6FPdb





or you could use a second small trickle charger . . . just connected to the starter.

like this: https://amzn.to/3aug2Mf




heres a cheaper un branded version: https://amzn.to/38hxEIY




.

or



you could swap out your existing Victron for a multi-chanel version that can charge BOTH the starter and Leisure seperatly . . .

eg: 12v 20A 3chnl - https://amzn.to/2R8zqXi



.

If your on EHU a lot, a second small charger like above should do the job.

 

[hoggle]

Thanks Del for your in depth reply. I might go with a second charger connected to the starter battery. In Deaky's reply he mentioned that he didn't expect the starter to be flat, me neither. The Engine light had come on when travelling down to Aviemore, could that be the cause?

 

[Dellmassive]

Thanks Del for your in depth reply. I might go with a second charger connected to the starter battery. In Deaky's reply he mentioned that he didn't expect the starter to be flat, me neither. The Engine light had come on when travelling down to Aviemore, could that be the cause?

if your only doing short trips, ie 30miles and under.

then you may not be giving enough time to recharge what your taking from the battery (this time of year). . . . . so a good overnight EHU charge would be a good idea.

a yellow engine light could mean loads of things . . . best do a code scan and see what fault codes are logged.

Carista is cheap if you havent already got it? to scan for codes = https://amzn.to/2uhXwFT

Carista - How I Done It -





dont forget that the van interior lights etc are all fed from the starter battery . . . .

so every time when camping you open the door etc the van powers up and will start draining the starter battery.



i would also suggest you look at getting yourself a jump-pack / booster so you can get yourself started if this happens again - you were lucky to get a jump-start from that camper.

have a look at these:

NOCO GB70 Jump-pack - https://amzn.to/2EONYo8

NOCO GB70 Jump-pack Case - https://amzn.to/2EKK5jN

 

[hoggle]

I had the Carista delivered to my door yesterday when i was away. So i have just been out and plugged it in, there is 18 faults!
P20EE, which is SCR Nox Catalyst Efficency Below Threshhold Bank 1
Engine 31103, ABS 00128 08208 08216 08217 08338, Instument Cluster 13635840, Airbags 13635840, Parking/Steering Assit 13635840 13893632, Cental Electronics 00532 00446 04194, Infotaiment System 01537 01539. Wish i never looked now!!
And the jump pack is a great idea, i will be getting one of them...

 

[Pete C]

I suspect a lot of those errors were caused by your flat battery.

Pete

 

[Dellmassive]

Vcds And Carista Fault Codes

 

[hoggle]

Hope so, i might just book it into the VW Garage as it's still under warranty..

 

[Dellmassive]

might be worth taking a not of them codes,

then clear them all and drive about for a week and see if any come back?

as @Pete C said a flat battery will cause loads of dodgy fault codes....

 

[hoggle]

I have screen shot them. I will clear them and do as you suggest. And thanks for your help!

 

[DaveyB]

You’ll regularly have 1 or 2 listed, doesn’t mean there is a problem, it just means the ecu saw a value that it didn’t think was quite right.
If you’ve disconnected speakers to mount aftermarket ones that run off an amp, you’ll permanently get speaker circuit fault, because the van can’t “see” the speakers anymore.

 

[hoggle]

I'm hoping as Pete said, most of the codes are flat battery related. I will clear them and see if any reappear..

 

[Farnorthsurfer]

Not directly related but am planning to install my Victron EHU charger with the cables arranged so that I can disconnect the charger output plug and use a 2m extension cable and ring terminal link fitted to the main battery so that I can easily swap it on and do an emergency charge or trickle charge it if I leave the van home for extended periods.
Clearly this won’t work like the booster referenced but would help in a pinch and has the advantage of being cheap and easy.

 

[hoggle]

That's actually a good idea! I will have to have something sorted for the next time i go away.

 

[Dieseldonkey]

Both leisure and vehicle battery are negative earthed to the van. As I understand it, the voltage monitor is on the negative side. Anyone see any issue with simply running a jump lead from the positive leisure battery terminal, to positive terminal on the vehicle battery, if a jump start is required.

 

[Farnorthsurfer]

Both leisure and vehicle battery are negative earthed to the van. As I understand it, the voltage monitor is on the negative side. Anyone see any issue with simply running a jump lead from the positive leisure battery terminal, to positive terminal on the vehicle battery, if a jump start is required.

Sounds good to me, just using the juice straight from the leisure battery I guess.
Although my terminals would be pretty hard to get to as it will be 8mm bolts horizontally positioned right under the pax seat.
A side note is that the Renogy DC-DC is supposed to trickle the main batt after the leisure battery is full. Not sure what it does about keeping the 20% headroom for regeneration. Don’t have my head round that yet.

 

[Dieseldonkey]

Could be a little bit easier for me @Farnorthsurfer . Got some fairly substantial leads running to my inverter. Its located in some dead space behind the kitchen units. A wee advantage of a twin slider, is it gives you a service door. The positive terminal of the inverter is easily accessible to get a jump lead crocodile clip on the positive terminal. Its cover just unclips. However, the feed cable is protected by a 100amp fuse at the leisure battery end. Just wondering what current the starter motor will pull.