| FBH Operating Parameters Question | |
Hi all, another FBH question:
In short, what is the lower V cutoff for the FBH? Vehicle manual does not say.
I’ve had mine set to come on for the normal 30 mins at about 0545. It’s been 3-4 degrees below zero here overnight so well in scope for operating. The heater is coming on but cutting out after about 15-20 mins, not managing to complete the cycle. There’s plenty of fuel, the vehicle is stone cold having not been started for many hours, so all I can think of is that the voltage hits the minimal threshold and cuts out.
I have a cheap battery monitor and the graph from this morning is below:
You can see the voltage is a reasonably healthy 12.3V, drops to something like 11.6-11.7V whilst FBH runs, manages just over 15 mins, then goes back to about 12.2V
Before anyone says that starting V is too low, I have contributed to many other threads on this topic and am convinced this is quite normal and within BMS parameters. I have a battery less than 1 year old, a new Denso alternator less than 8 months old, and monitor the battery V very regularly. Due to the way BMS operates, it is very rare that I see 12.4V or above before starting the vehicle, especially in winter.
Therefore if the cut off is something like 11.6, this seems a little high. Can anyone add any detail on this threshold?
Many thanks in advance as ever! 🤣 Andy
2010 4.4TDV8 Vogue SE in Santorini Black with Ivory interior
2017 Audi SQ5 3.0 V6T Quattro in Volcano Red
2001 Audi Allroad 2.5 TDI manual with low-range in Highland Green. Currently SORN whilst undergoing some serious restoration!
|
24th Jan 2023 11:40am
. So its not about battery voltage I suppose, something else cut it of.
