T6.1 Battery low warning

[lambo]

If the stop start doesn’t work it could be doing a regen to clean the DPF especially if it’s been sitting about and not doing long runs. I would take it for a run with stop start turned off and don’t use it in the winter when you have a lot running.
it doesn’t sound like you have the correct battery if it’s just a normal wet battery.

It's a VARTA 5TA 915 EFB battery. So not a normal flooded but not a fancy AGM either. Somewhere in between from my limited google-based knowledge...

 

[AussieMick]

A good smart charger and using it when van is not used much, ends up much cheaper than having to replace the battery, not to mention the van will start and run more reliably. Batteries like to be kept charged for a longer life.

 

[EdH]

Is Ctec charger 3.8 any good for charging t6.1 main battery? Not using a van at all now. Wales in lockdown now for while I think. We went camping last weekend, some 45 miles from home, and start-stop didn't kicked at all and only after we reached our campsite. I got one of those cigarette lighter voltage monitors, an I could see amps jumping up to 15v when going downhill and on occasions when braking, so it's charging but obviously not enough. Had a look earlier through the window, resting amperage is showing 12.3-12.4v.

I don't know if my 70 plate campervan main battery is AGM (it has a fuse box on the top, installed by the converter, I can se it's Exide brand). Looked under the passengers seat for a leisure battery which is clearly marked AGM Varta 75amp, which appears to be a VW factory fitted (factory fitted swivel seats).

 

[Pete C]

Yes, just leave it on for decent amount of time, as it is a fairly low current device.

Pete

 

[AussieMick]

Sounds like you need a decent smart charger, a run of 45 miles wont do much charging. If not using your van much then it will need regular charging to prolong the life of your battery.. Someone with a CTEK 3.8 may post here to let you know if its big enough, probably fine to leave hooked up for charging over long period. Your little cigarette lighter voltage monitor is measuring volts not amperage , amps is current .
If not using the van for long periods leaving the little volt monitor plugged in is helping to drain the battery , better to just stick it in to get a voltage reading then remove it.
If you are charging a battery ,leave it on charge until charger tells you its fully charged or 24 hours as a battery wont charge in an hour or so . It would be good for you to know what your starter battery is as this needs a charger to match its type, you may need to carefully , temporarily remove whats obstructing the battery information.
Just saw post above by Pete C

 

[Samro]

It's a VARTA 5TA 915 EFB battery. So not a normal flooded but not a fancy AGM either. Somewhere in between from my limited google-based knowledge...

It sounds to me like

Dies seem odd doesn’t it? I charged it up with my entry level charger (luckily my battery is entry level not Agm!). Went for a drive auto stop start works. Cool. On the way home so in theory more charge - doesn’t work, get the icon with the line through the A when I stop. There may be more to it than that but looks suspicious

It sounds to me like the charge that you've given your battery is insufficient or you've got more going on. (in the form of the leisure battery stealing power from the starter battery through the D.C.-D.C charger.)

If you charge any battery properly, the battery will receive a bulk, then absorption, then float charge. If you disconnect the charge before the charger has completed its absorption charge phase then the battery voltage will naturally discharge faster than expected.

If it's not this then assuming that you've charged your starter battery for long enough and it is fully charged then when you are going for a drive, your leisure battery will load the starter battery to receive a charge through the D.C.-D.C charger. This will probably be enough to give the issue which you refer to.

Are you sure that you've not got a load on the leisure battery when parked? This will give you the exact symptom that you describe as the leisure battery will be stealing as much voltage from the starter battery as your D.C-D.C charger will allow.

Limiting the disconnection voltage could solve your issue if you need to leave loads on when the vehicle is parked. Take a look at Battery Protect - Victron Energy

 

[Phil_G]

If you're going to be parked up for extended periods when the van isn't being used then like others have said... get yourself a good charger... Something like this is quality bit of kit and money well spent... NOCO 10A

That type of charger is fine for treating flat batteries but you really shouldnt let it get to that state. The idea of a maintenance charger is that it is left on. That way it can monitor self discharge and choose an appropriate charge profile. Most of the time it will be floating with is the optimum for long battery life. Habitually letting the battery drain then fast charging at 10+ amps is not ideal for longevity. If your van is laid up for a length of time a smart maintenance charger like the 3.8 is ideal provided you leave it connected and let it do its thing

I once tried a CTEK 3.8 on mine... It got there eventually... but took over 36 hours to get a decent charge into it...

A smart maintenance charger will take a long time to bulk charge from flat, thats not its intended purpose
My suggestion is that something like the 3.8 is ideal if you want to look after your battery in a laid-up van
Cheers
Phil

 

[Samro]

I beg to differ . The idea of a maintenance charger is that it is left on. That way it can monitor self discharge and choose an appropriate charge profile.
Most of the time it will be floating with is the optimum for long battery life. Habitually letting the battery drain then fast charging at 10+ amps is not ideal for longevity. If your van is laid up for a length of time a smart maintenance charger like the 3.8 is ideal provided you leave it connected and let it do its thing

I agree you @Phil+G, as a quality charger will maintain the starter battery voltage, but for the sake of establishing why @lambo 's start-stop issues are present, he really should check that his problem is not due to his leisure battery discharging when his van is stored.

If a quality charger is used to maintain the starter battery his issue may not be fixed and he may also find that the leisure battery has an incredibly short lifespan. There is no detail on what kit is fitted to his vehicle and its worth a check.

It is worth noting that if the input voltage of a DC-DC charger isn’t set to a sensible voltage and the leisure battery is flat; then it is likely that the vehicle will throw up a low voltage warning until the leisure battery is charged and the starter battery voltage can increase to a suitable level...... this could take ages!

 

[Dilbert]

Don't forget to connect any charger to the battery positive and a chassis point on the vehicle. Otherwise your van will not know how much charge has been put in to the battery (due to battery management software monitoring in the battery negative return current). Do not connect the charger directly to the battery negative terminal.

 

[EdH]

I got cigarette lighter plug (never used it before) as well with my Ctec charger and I could connect my van via EHU, and then internally use vans electric socket to plug the charger into lower dash 12v. This way would maintain both leisure and starter battery. Is this viable method of charge (starter battery), or would I be better off plugging the charger into the battery directly (negative on chassis point of course) and let it to do its job?

 

[CAB]

I got cigarette lighter plug (never used it before) as well with my Ctec charger and I could connect my van via EHU, and then internally use vans electric socket to plug the charger into lower dash 12v. This way would maintain both leisure and starter battery. Is this viable method of charge (starter battery), or would I be better off plugging the charger into the battery directly (negative on chassis point of course) and let it to do its job?

I have my Ctek 5.0 plugged in this way, it seems happy enough like that.

 

[Noddy996]

Me too!

 

[lambo]

Where would be a good place to attach the negative charger wire? When you say chassis do you mean bare metal within the engine bay? Is there an obvious point?

 

[Pete C]

The bonnet hinges mounting bolts are right beside the battery.

Pete

 

[AussieMick]

I had 0 ohms between both side bonnet bolts to each other, but 60 ohms between them and engine block main ground lead so might pay to check resistance reading with a multimeter . My panels must somehow be insulated from main frame.
It played havoc with my battery charger till I found a bolt that was 0 ohms to main ground point

 

[Martymuffin]

Where would be a good place to attach the negative charger wire? When you say chassis do you mean bare metal within the engine bay? Is there an obvious point?

Hi Lambo, did you ever find the reason for discharge. Thanks Marty.