Battery charging from cig socket

[roadtripper]

Is it the sockets turning off or is it the charger timing out.

I know on my CTEKs if the battery voltage/current doesn't behave as expected in the right time for the charging phase it times out and shuts down. It does put up an error light though.

Which charger are you using?

 

[roadtripper]

Shows you have to treat the diagrams (and advice given) with caution and take note of the “rough guide” disclaime

Thanks for the update, glad it's not just me that ends up with the diagrams and pictures of the actual fuse boxes like some police investigation diagram trying to relate them

 

[Samro]

Is it the sockets turning off or is it the charger timing out.

I know on my CTEKs if the battery voltage/current doesn't behave as expected in the right time for the charging phase it times out and shuts down. It does put up an error light though.

Which charger are you using?

I am sure that this is a case of the socket not allowing the battery to charge.

When connected via either socket, the charger starts off normally and runs fine for an hour. The charger then ends up showing as being in absorption at 14.4v (viewed via Bluetooth) and yet the starter voltage just falls back to a resting voltage.
I have a Victron Blue Smart 25/12 charger and it charges the battery fine if connected to the battery properly. (IE-not via cigarette socket, but still in low mode at 10A)
See below screenshot from attempted charging via cigarette socket:
Start of charge at 1846 shows bulk charge, then as you'd expect the charge to reduces to float by about 1915.


All is well until about 2000 or so in and the charge just stops:


By contrast, using the same charger connected directly to battery, it can be seen that charger was started at 1910, briefly bulk charged, entered absorption and then float charge at around 2am, which is exactly what I'd expect:


Until charge was disconnected at 730 am.


So charger is charging exactly as expected, unless charged via a cigarette socket.

What is bothering me is I know for a fact that the cigarette socket is live as if I leave a usb charger plugged into it and observe the LED glowing for hours on end!

It is though there is some sort of diode installed to prevent charging from the sockets and this diode takes an hour or so to decide to kick in!
Maybe VW have designed it like this so that they can keep a van alive long enough for maintenance, but not long enough to allow continuous charge?

I remain a little confused over what is going on.

 

[roadtripper]

I do wonder at this point is something doing some form of thermal management or possibly discharge protection.

Because an hour at 10A is generally where you'd expect the socket to be getting a bit warm.

Or given that something measuring the current in the van will have no idea of direction it's seeing a high load without the engine runnings so cutting it off to save discharge (not realising it's a charge current)

Do you have a less meaty charger you could try?

 

[Samro]

Do you have a less meaty charger you could try?

No I don't. I'm happy to buy one, but until I identify what is causing the disconnection I didn't want to waste my money.

 

[archersam]

Pretty simple solution - if you are happy to use this charger AND want it inside the cockpit, just run an appropriate pair of cables from the battery, tuck it away somewhere like the glovebox and use a quick release connector. I did this in my old TT many years back with an Optimate and have the same in my Westfield in the footwell using something like this:

https://www.amazon.co.uk/OptiMate-SAE-Weatherproof-Eyelet-Lead/dp/B0022ZZULK/ref=sr_1_15?keywords=sae+battery+connector&qid=1701336201&sr=8-15

I haven't looked back to see your skills, however I am sure as you are in here running a cable from the battery into the van shouldn't be too challenging

Or maybe mount it on something with something like this:

https://www.amazon.co.uk/Connector-Linkstyle-Weatherproof-Sidewall-Generator/dp/B0C6M77V4F/ref=sxin_18_pa_sp_search_thematic_sspa?content-id=amzn1.sym.431c6c06-e77e-44d9-a42c-721ab4612e9e%3Aamzn1.sym.431c6c06-e77e-44d9-a42c-721ab4612e9e&cv_ct_cx=sae%2Bbattery%2Bconnector&keywords=sae%2Bbattery%2Bconnector&pd_rd_i=B0C6M77V4F&pd_rd_r=8843e1e4-b0ab-4953-8211-784c6321e869&pd_rd_w=RuNkF&pd_rd_wg=nVgzF&pf_rd_p=431c6c06-e77e-44d9-a42c-721ab4612e9e&pf_rd_r=J6CAR2ABNSQ5QNG61FE0&qid=1701336201&sbo=RZvfv%2F%2FHxDF%2BO5021pAnSA%3D%3D&sr=1-3-ad3222ed-9545-4dc8-8dd8-6b2cb5278509-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9zZWFyY2hfdGhlbWF0aWM&th=1

 

[Samro]

I found an old Ctek M100 charger at work and so I bought a cigarette socket adaptor and gave that a go.
This charger is a 7A (Max) output and I used this overnight last night and all was well.
I guess this proves that in addition to fuses, there is some overload/overheat protection on the factory fitted sockets and I'd be interested if anyone knows how this works?

 

[roadtripper]

I found an old Ctek M100 charger at work and so I bought a cigarette socket adaptor and gave that a go.
This charger is a 7A (Max) output and I used this overnight last night and all was well.
I guess this proves that in addition to fuses, there is some overload/overheat protection on the factory fitted sockets and I'd be interested if anyone knows how this works?

I think it cuts off after about an hour....?



On a serious note glad you got it sorted, one for the forum knowledge base certainly.

 

[Daniel_R]

Thanks for all the excellent guides and threads on starter battery charging/maintenance.

With this method of charging the starter via the cigarette socket, are there any precautions to take charging the starter from a socket in the van when on EHU (or just straight from the mains for that matter) where starter and leisure are a different chemical composition? My set up (though I've yet to try the NOCO):

- NOCO Genius 5 plugged into the 'always live' cig socket (t6.1)
- Victron controllers: blue smart, orion tr smart non isolated dc/dc, smart solar mppt 75
- Roamer LiFePO4 105ah (BMS)
- MOL EAB starter (lead acid I believe)

Should I disable charging on the victron dc/dc when charging or maintaining the starter?

Cheers

 

[roadtripper]

Nope they are totally separate, just set your charger for the chemistry of the battery you are charging

I suspect you mean EFB (not EAB) which you can charge as an AGM.

On a side note I'm surprised to see a MOLL in a 6.1 - they are very prone to failure it seems and you might want to keep an eye on it.

 

[Daniel_R]

Nope they are totally separate, just set your charger for the chemistry of the battery you are charging

I suspect you mean EFB (not EAB) which you can charge as an AGM.

On a side note I'm surprised to see a MOLL in a 6.1 - they are very prone to failure it seems and you might want to keep an eye on it.

Great, ta.

Noted re. the MOLL, I thought that might be the case. The EAB bit confused me too, my best guess was that "absaufen" is German for flooded.....