LED light strobe

beantins

I have an 08 vectra and the dips are absolutely brutal. I fitted a set of osram nightbreakers and also a set of halfords led side lights to try brighten things up. The leds are canbus compatible and not showing any warning lights. The only problem is that when i switch the car off and lock it they strobe ie blink every few seconds for a minute or two. They stop then but im jst wondering are they still consuming power and will they kill battery? On googling i seen it mentioned that its the car doing checks after shut down but it doeant say whether or not it will kill the battery. Much appreciated if somebody with more knowledge could help me out. Thanks

Alanstrainor

The LEDs as side lights wont brighten anything by much surely? I would't bother with them at all to be honest. It is obviously using some juice, but I wouldn't think there's enough there to cause any significant drain on the battery. They're probably 1watt or something.

beantins

Osram nightbreakers being the main upgrade. Just not sure whether they stop using power after the strobing stops or use power all night

Miscreant

If the LEDs are CANbus compatible then they might have a small capacitor on them that is causing this flashing as it discharges. The car should not be providing power to the bulbs once it is off in any case so I doubt that the battery would go flat in a minute or two.

ironclaw

Miscreant wrote: »

If the LEDs are CANbus compatible then they might have a small capacitor on them that is causing this flashing as it discharges. The car should not be providing power to the bulbs once it is off in any case so I doubt that the battery would go flat in a minute or two.

Capacitor won't cause a flash on its own. To flash something, you need to charge and discharge. So the capacitor would need to be charging and discharging fairly rapidly within an RC circuit.

What you are seeing OP is the car doing a check on the canbus for blown lights. It sends a few bursts of power down the line and measures the resistance. By measuring the resistance it can determine if a bulb is blown. It's why when you put in LEDs that are not canbus compatible that you get a blown blub warning, the car figures the resistance is too low and triggers an alert. You combat this by putting a resistor in the LED light, which gives the impression of a normal blub.

To answer your question, no, it won't drain your battery for two reasons 1) It only does a very brief check and stops and 2) LEDs don't consume a lot of power, so even if it did go on all night (which it won't), your battery would barely take a dint. Further remember that most cars are pretty smart with respect to battery drain. If they detect a drain, they'll shut down that circuit to avoid the battery going flat.