After our disastrous experiences with charging point unreliability over the holidays (just before and on Christmas Day) we had a significant loss of confidence in the public charging infrastructure. When it came time to drive to the airport for a trip abroad for New Year we had some soul searching to do.
I decided to go ahead with taking the ZOE, but with a very different approach to charging since the previous one had been so unsuccessful. Previously I assumed a typical range of 80 miles and looked for one or more chargers close to the point at which I would be running low on charge.
The new strategy was a two-pronged approach:
- Given that charging could not be relied on, always drive in Eco mode and as carefully as possible so as to maximise range, and to maximise the amount of charge remaining at all times (i.e. ‘assume the worst’, that it may be necessary to go hunting for chargers). To make this work meant leaving earlier than we otherwise would so we could travel more slowly and consistently without worrying about being late for our flight.
- Plan ‘opportunity charging’ – i.e. don’t just charge ‘at the far end’ but charge at each fast charger passed on the way there. This idea I think of as ‘farblue charging’ as it was suggested by farblue, a member of the forum, in writing about his ‘big adventure to London’.
- In general accept whatever charge is provided, even if it’s not what you want. In other words, if a fast charger (43kW) only gives you a medium charge (22kW) then use that rather than go on further to the next fast charger – ‘a bird in the hand’ approach.
We set off from Northampton at 0825 on 28 December headed down the M1. Our flight to Vienna was from Heathrow at 1230. By 0845 we were at Newport Pagnell South services, still with 75% charge, just to get an opportunity charge at the Ecotricity 43kW fast charger. On the first attempt the charger reported an ‘anomaly’. On the second attempt it started charging but with one hour predicted until completion. Given that the car didn’t need much charging this implied that it was charging at a very low rate, probably 7kW, which was too slow in the circumstances. We used the facilities, unplugged at 0905 (with just 10% charge gained) and headed south again.
Following the same approach we stopped at the next services, Toddington. Here we found a ZOE owner named Terry trying unsuccessfully to charge, and concluded the charger was broken. After using the facilities, and just before heading out on the road, we decided to test the charger ourselves anyway. Oddly enough it worked, though not at maximum power (perhaps 22kW). We took advantage of it anyway and charged from 0940 to 1020, increasing the charge from 66% to 97%. I cut it short since the last few percent always take disproportionately long.
The original plan included contingency to continue along the M1 past the fast chargers at Edgeware and IKEA Wembley. However, since we now had plenty of charge, and time was getting on, we drove straight to the airport. We arrived with a couple of hours to go before the flight which was not as much as we would have liked (by the time we got through security there wasn’t time to eat) but was good enough that we weren’t worried about being late for the flight.
We returned on 2 January and picked up the car (I had deliberately chosen long term parking where you don’t have to hand over your car keys as I was concerned about having someone new trying to drive the ZOE). Although we still had about 30 miles of range, the first order of business was to fill up. Ironically there is a fast charger at Heston services on the M4 just a few miles from Heathrow but you have to drive all the way into London to pick up the start of the motorway and head back out again in order to get to it (there is no westbound charger). Anyway, that’s what we did.
As before it seemed to charge at about 22kW but after a hot chocolate and a break we were ready to go on. Our plan was to return to Northampton via Kidlington (due to a family birthday) so we headed up the M25 and M40. Following the same strategy we called in at the 22kW chargers at Waterstock just outside Oxford on our way. They worked fine, after which we had plenty of charge to get to Kidlington and then back home to Northampton.
The ‘little and often’ strategy had worked out well for us. However, there are costs to this strategy that are important to consider:
- You will likely charge more often, and there is a time cost to doing so (pulling into services, connecting up, etc.).
- You will spend more of your usable range detouring to charge.
- Charging will be slower – charging an empty battery can be more than twice as fast as for a full battery, so overall you will get more charge per minute when filling an emptier battery.
In conclusion, however, the new strategy worked well as we had none of the panic or disrupted plans that result from finding not working a charger you are relying on. I will therefore continue to use this strategy until I feel the charging infrastructure is good enough to rely on.