Speak EV - Electric Car Forums banner

1 - 12 of 12 Posts

·
Registered
Joined
·
8,106 Posts
Discussion Starter #1
I spoke to Trevor Hill this morning. Trevor runs the MyAmpera helpline.

We had a very interesting discussion about range and how to get the very most from the Ampera.

He suggests that we use HOLD mode when on faster roads like motorways. In HOLD mode the petrol generator generates the power for the motor and on faster roads it can come on and stay on meaning it is running at its most efficient.

The logic behind this is that EV mode works at its very best in town and low speed, stop start situations. So, if you know that you will have some driving at slow speed later in your journey then using hold mode allows you to utilise the battery for that part of your journey using the petrol generator for the faster parts when it can run continuously reducing the stop-start aspect which is what it would do if you used all the battery on the faster part of the trip leaving the petrol generator to take over on the slower part.

Clearly this may not be possible or it might not be easy to assess but as a principle it looks sensible.

Also, what does seem to be an overriding imperitive is that each time you fully charge you start with an empty battery. That way you can be sure that you have maximised the use of EV mode on each full charge.

Topping up does not count. It just topping up then that can be done at anytime. It is only at each full charge (i.e. charge to 100%) that you should try to have used all the battery and used the least petrol.

I shall try to put this concept into practice and see how it works out. If it doesn't then I might be posting again to disagree but for now it seems to make a lot of sense :)
 

·
Premium Member
Joined
·
11,244 Posts
Of course, in an ideal world the car would use the navigation data for your journey and your speed to select the best mode for each mile of your trip. With the current Nav not even supporting full UK postcodes, I guess I'll be waiting a while for that ;-)

First, let's remind any newbies reading that 'Hold' was designed to keep battery power for entering (ZE) zero emissions areas which are (most likely) coming to some parts of EU cities. The concept is that in ZE areas there will be emission monitors and if your car is found to be non-ZE you will get a fine [a stick to go with the carrots].

To use Hold for anything other than this we need to think it through carefully. If you leave home fully charged and press Hold immediately, then you will not be able to store any regenerative energy. For example the energy used for slowing down from 70 to 50 on the motorway due to a bit of traffic would be lost.

I guess we could drive a few miles on EV and then engage Hold, but I am prone to forgetfullness so could easily see me getting to my hotel or friends (where I can charge) with an almost full battery :-( The other risk is that I'd hit a stop-start motorway jam and forget to switch back (I might hear the engine in this situation but perhaps not if the Bose was turned up loud...)

My only regular long journey is almost all motorway, so I can't conduct a useful test at present. I'll be interested to hear what difference others achieve [Disclosure: I'm sceptical it will make that much difference in a proper like-for-like test]

While I remember, in Range Extender (RE) mode on my M4 journey back yesterday I dropped my speed from 70 to 65 and it didn't really make much difference to my MPG, the average over 40+ miles was still 45-46 MPG. Driving slower that 65 is too boring to even test, so I'll be back driving at 70 next week!

Regards

Paul R
 

·
Registered
Joined
·
8,106 Posts
Discussion Starter #3
proddick said:
Of course, in an ideal world the car would use the navigation data for your journey and your speed to select the best mode for each mile of your trip. With the current Nav not even supporting full UK postcodes, I guess I'll be waiting a while for that ;-)
Very true. This was a surprise to me. The Leaf supports full postcodes so I kind of assumed the Ampera would too. Silly me!

To use Hold for anything other than this we need to think it through carefully. If you leave home fully charged and press Hold immediately, then you will not be able to store any regenerative energy. For example the energy used for slowing down from 70 to 50 on the motorway due to a bit of traffic would be lost.
Very good point. I suppose it depends on your journey profile but yes, it is a bit silly not to use some batetry right from the start to give you headroom for regen. Perhaps there is a sensible modification to all this such as only engage HOLD mode once at least one or two bars of battery capacity is used?

I guess we could drive a few miles on EV and then engage Hold, but I am prone to forgetfullness so could easily see me getting to my hotel or friends (where I can charge) with an almost full battery :-( The other risk is that I'd hit a stop-start motorway jam and forget to switch back (I might hear the engine in this situation but perhaps not if the Bose was turned up loud...)
I think I would be rather forgetful in that way too.

My only regular long journey is almost all motorway, so I can't conduct a useful test at present. I'll be interested to hear what difference others achieve [Disclosure: I'm sceptical it will make that much difference in a proper like-for-like test]
Yup... I'm rather skeptical too. Trevor did think it was worthwhile as he has driven the Ampera all over the country and has solid experience. I am sure it does make a difference if done carefully but is it worth all the thinking effort? Probably not in my view. Just an interesting discussion on Ampera efficiency I suppose ;)
 

·
Registered
Joined
·
138 Posts
It was exactly this tecnique that enabled me to get at least 41 miles from a charge (with a very small bit left when I arrived home) so I can endorse the recommendation. The logic seems pretty sound to me

I will admit that the stretch of motorway that I drove along in hold mode also had a 50 MPH limit for roadworks so it remains to be seen what "regular" motorway useage delivers when I have the opportunity to compare like with like.

Accept the issue of remembering to turn back to Normal mode but while it's still a novelty I'm sure it won't slip your mind!

Big Paul
 

·
Premium Member
Joined
·
11,244 Posts
On my longer "M4" journey my aim is to complete it at the lowest cost driving at 70 mph. As the cost to charge the car is low (free if I stay at the hotel) my aim is to use it all up - I don't want to arrive back home/hotel with any! The variable cost for my journey is "how much fuel did I use"

I obviously respect Trevor's extensive experience with the Ampera, but we all drive differently on different roads so I'll still reserve judgement on the effort vs. benefit of using Hold until I try the approach in my semi-controlled test.

There is an alternate route I can take to my "M4" customer where I come off the motorway earlier and take slower A and B roads for the last part. I will take this route twice to try both approaches and see how much petrol is used.

For my journey, the better result is the one that uses the least petrol - how many miles I do on EV doesn't matter.

Regards

Paul R
 

·
Registered
Joined
·
8,106 Posts
Discussion Starter #6
Paul, Trevor is in total agreement with you on that as am I... I think I made that point in my original post, specifically:

Make sure you use all the battery by the time you next fully charge.

To get the most financially out of the Ampera it is important that the battery is used as much as possible as it is the cheapest way of travel. However, it doesn't matter whether you use all the battery at the start or at the end. The point Trevor made is that providing you do use up all the battery before you next fully charge it makes sense to use the battery at times when you it is most sppropriate i.e. slower speeds, stop start etc. I am certainly not suggesting that you rigidly use ER mode on motorways and battery off. It will depend on your particular journey and if your journey is 30 miles motorway and 1 mile off then you should use all of the battery up before you next fully charge and in that case you would drive in EV mode on the motorway.

However, if you did have a trip that was 50 mile motorway and 20 mile off then it might be cheaper to save half the battery (or perhaps under to make sure you have zero battery before the end) and use that battery power on the 20 miles... where it is most suited.
 

·
Registered
Joined
·
54 Posts
Hi- just my method of a longer journey
I've had to drive to London a few times over the Christmas break ( you don't want to know) It's about 130 miles return. Northampton to London
1 Electric to the M1 about 2 miles
2 Hold until I get to slow traffic - usually Luton
3 electric until through congestion- usually when I get passed m1/ m25 junction
4 hold until north circular ( bottom of M1)
5 London bit and back to m1 in electric
6 hold until I reach traffic (Luton )
7 electric through the congestion
8 hold until the remaining range lets me use up the battery about j13/14

Does this make any sense - I've been pub

Thx
 

·
Registered
Joined
·
3,308 Posts
Hi- just my method of a longer journey
I've had to drive to London a few times over the Christmas break ( you don't want to know) It's about 130 miles return. Northampton to London
1 Electric to the M1 about 2 miles
2 Hold until I get to slow traffic - usually Luton
3 electric until through congestion- usually when I get passed m1/ m25 junction
4 hold until north circular ( bottom of M1)
5 London bit and back to m1 in electric
6 hold until I reach traffic (Luton )
7 electric through the congestion
8 hold until the remaining range lets me use up the battery about j13/14

Does this make any sense - I've been pub

Thx
That is pretty much what I would do too, unless I knew I was charging in London. :)
 

·
Registered
Joined
·
1,338 Posts
Hi- just my method of a longer journey
I've had to drive to London a few times over the Christmas break ( you don't want to know) It's about 130 miles return. Northampton to London
1 Electric to the M1 about 2 miles
2 Hold until I get to slow traffic - usually Luton
3 electric until through congestion- usually when I get passed m1/ m25 junction
4 hold until north circular ( bottom of M1)
5 London bit and back to m1 in electric
6 hold until I reach traffic (Luton )
7 electric through the congestion
8 hold until the remaining range lets me use up the battery about j13/14

Does this make any sense - I've been pub

Thx
Yep makes good sense.
 

·
Registered
Joined
·
455 Posts
Whoa! Took me right back to the beginning, May 2012, happy days. I knew even less then but haven't regretted a single EV moment. Roll on the New Year. Back to the cupboard now to drain another 2015 left over bottle of whatever. All in the interests of glass recycling don't you know!!
 
1 - 12 of 12 Posts
Top