S Max Heated windscreen/ battery issues

[Tracy p]

I have a 66 smax and the heated windscreen keeps stopping working.   It has been back to the dealers twice and they say it is because of a low battery as every time they charge the battery it works.   They are saying that I dont do enough miles /long enough journeys to maintain the battery charge. I have pushed back and they are adamant.

Any thoughts? Anyone have the same problem?

Thanks 

[WES180]

I only do less than 4000 miles a year but use the car daily so my battery is probably getting a low top up from the alternator too but my HFS works fine.

It is hard on the battery over winter due to having everything running at once, HFS, heaters, lights, radio.

What sort of mileage are you doing daily?

Have you had the battery tested anywhere to see if it's faulty?

[Abbadon]

If you are doing only a few miles a day, like 2 or 3 school runs as my wife does some days, it can hammer the battery with almost no charge time between starts, so it isn't a ridiculous thing for them to say unfortunately.

However, the alternator should be specified to be able to supply the full amps needed to run the screen along with other systems, otherwise you would drain the battery at anytime its used, which I won't believe would be the case, and woukd be awful design. Even slow driving runs the alternator fast enough for a decent output, although engine idle won't give you full amps if you called for it, so if you turned on screen with car sat I guess it might decide the battery was needing charging more importantly than running the screen, so that could, I guess be the mechanism at play here.

Sent from my SM-G950F using Tapatalk