Battery charging through regenerative braking.

[mmi]

• Engine start at 30 s.
• Start of downhill at 100 s - foot off the throttle. Slight touch on the throttle at 108 s.
• Again foot off the throttle at 180 s, at 200 s, and very briefly at 220 s.

In this case regenerative braking gained approx. 5 Amps more charging during 100-160 seconds. Unfortunately the benefit further down the route will be less and less as the battery fairly soon has catched up the discharge from starting (below).

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[dubber36]

Either way, clever alternators, coasting and stop/start save bugger all fuel in the real world.

 

[DaveD]

Either way, clever alternators, coasting and stop/start save bugger all fuel in the real world.

Agreed, the added complexity isn't worth the tiny annual saving on fuel IMO, as with everything in vehicles these days it's all about emissions testing.

 

[Pete C]

There's another dimension to this. People talk about taking the van out for a drive to charge the battery, but the best % charge you are likely to achieve under normal circumstances is 80%.
For us, this is important, as our van is a camper and may not be used for a month or so. This is why we always charge it fully with a battery charger before we take it down the yard. This has meant that it has never failed to start, even after being left for 6 weeks in the depth of winter.

Pete

 

[t0mb0]

There's another dimension to this. People talk about taking the van out for a drive to charge the battery, but the best % charge you are likely to achieve under normal circumstances is 80%.
For us, this is important, as our van is a camper and may not be used for a month or so. This is why we always charge it fully with a battery charger before we take it down the yard. This has meant that it has never failed to start, even after being left for 6 weeks in the depth of winter.

Pete

My starter is trickle charged from the solar panel and given it sits on our drive it means the starter basically lives at 100%.

 

[Skyliner33]

Actually no, the regenerative braking takes place only when engine braking takes place - so foot off the throttle when moving - manual gearbox gear engaged or DSG coasting function off.
Just the heater blower at 2 or higher - you'll get the minimum 13.4 Volts, or depending on battery's state of charge even up to 14.8 Volts (the same as at regenerative braking).

Interesting, I wonder of this is partly the reason the coasting function has been removed now?

 

[Skyliner33]

So if VW are stating in the Vehicle Handbook to leave the AC running at all times that would tend to mean that the blower is on 2 or more as well. In which case the 80% economic battery charge is void?

Why dos having AC running mean the blower 2 or more, why cant the fan be set at 1?

 

[DXX]

Why dos having AC running mean the blower 2 or more, why cant the fan be set at 1?

I guess it could be set at 1, but this seems to be a known cause of resistor pack failure.
In a van without a bulkhead setting 1 isn’t really moving enough air to make a difference.

 

[Salty Spuds]

Running the AC disables stop/start....

Not sure about that. Our AC is permanently on, yet the stop/start works as normal.

 

[Tsixty]

Not sure about that. Our AC is permanently on, yet the stop/start works as normal.

Same here

 

[Jez8543]

It doesn't

Not on mine