Start/Stop with Car Audio Upgrade Fear

Cocksure

I would be very grateful if someone could put my mind at rest in regards start/stop and amp drainage on the battery.

My VW T6 van has start/stop but I am afraid to use due to the fact that I have 3 power amps in the vehicle and I fear the battery being drained of too much power when the engine isnt running in start/stop mode.

The amps will drain the battery to below enough power to start the engine in about 15 minutes if they are the only thing on, but add in lights on, wipers running etc and I would imagine it is much quicker (enough to worry me).

I'm I right to be concerned or do vehicles have a built-in safety device that will auto start the engine if the drain on the battery is too much whilst in stop mode of start/stop. All the guides about start/stop are with OEM equipment, so having aftermarket makes me wonder.

PSM1

The start/stop system will monitor the output from the battery and if it drops below a certain level it will switch the engine back on or if it is below the threshold it will not stop the engine. I will find on my car that the stop/start will not operate if I have a lot of things on the car on like stereo, heated front and rear screen and heated seats all on at the same time. So the system will not allow the battery to drop to a level where the engine can not be restarted.

nvingo

Likewise, when we were playing with the OE 'toys' in my dad's new Ford Edge, we were warned of low battery (entertainment system started shutting down) before it dropped too far.

Cocksure

That’s what concerned me the most as it doesn’t shut down but instead just drains the battery.

I’ve had a few times when the battery is too low for the start stop to engage, but I’ve also had it kick in in the middle of the night with wipers fully on etc, however assuming I’m reading @PSM1 right I need not worry as the system monitors the battery level and will restart the engine if the drain is too much on the battery?

PSM1

Correct, the system will monitor the battery and will restart the engine before it drops too low and will not stop the engine again until the battery level returns to a 'safe' level.

Cocksure

Lovely, many thanks for the posts and putting my mind at rest

Start/Stop here I come

John7

With such a high power draw form your 3x amps, I'd be inclined to fit a dedicated secondary battery of suitable capacity. I understand the T6 has the provision for installing a secondary battery so you might want to look into that.

What is the Ah rating of the battery you have?

Cocksure

VW dealership refuses to do it as it didn't come with one and instead said that I need to go elsewhere. Have thought about having another battery fitted, but due to the fact that I have a smart alternator (DC to DC charger needed) and given the fact that I have been told (T6 Forum) that alterations need to be made in the vehicle VCDS system for it to work correctly I'm not keen on doing this via a 3rd party when the van is only 6 month old. If VW would do it then I would like a shot, 3rd party...

Thankfully the alternator is 180 amps so it does provide enough power (no flashing headlights etc), probably close to its limits, but it does cover it. Not sure what the AH of the battery is and can't check as the van is back at the dealership with a clutch fault which is its 2nd major fault in 6 months. Still love the van though

Desmo

I was never a fan of start/stop so turned it off most of the time anyway.

tommitch

As mentioned previously, I believe certain requirements need to be ment before it activates Start/Stop. I always leave it on in my car but it doesn't actually activate every time I stop.