The latest….


Well its week 3 with the Nissan Leaf and all seems to be going well. Its a lot colder this week, and wetter, and darker. Bad grammar aside these things put a lot more strain on the battery since all the little niceties we completely take for granted with a fossil fuel car, such as lights, heaters and wipers use electrical power. Lights and wipers not that much, the first generation Leaf that I have, has LED headlights which use barely 40w, the wipers similarly use very little power. The heater on the other hand is a bit of a volt-guzzler.

The thing about cars with internal combustion engines (ICE) is that they are at best about 30-35% efficient, so even with a modern small diesel engine, around 2/3 of the fuel is not converted into movement, mostly it is converted into heat. On a cold day a small fraction of that heat is more than enough to keep the car warm, albeit after a short wait for the engine to warm up. In an electric vehicle (EV) this is not the case and my heater when first switched on uses 4kW of electrical energy, which noticeably reduces the range. From an 80% charge (which is the charge level recommended to maintain the best battery longevity) the range is around 77 miles, which drops to 63 miles with the heater on. This does improve as the car warms up, the heater reduces its energy usage to around 0.5-1kW. One small bonus is that the heat is practically instant.

However Nissan have thought of (almost) everything and one really fantastic feature is that the heater can be triggered to switch on using the web/phone app which communicates with the car, and since the car is at this point plugged in to the charger in my garage this does not use up useful range. You do have to run it for about 20-30 minutes though as initially the heater uses more power than the charger can supply and therefore nibbles away at a bit of battery before it settles and the battery tops-back up.

As for charging stations I am still using the portable charger or EVSE which nissan supply. This charges at 10A from a normal plug and is the slowest charging method. However I should soon have a 32A charger installed in my garage (free under a government grant) and I will be able to use 16A from this charger to charge in approximately 4 hours. I have gone with 32A as later EV’s have higher powered built in charge circuits and can utilise higher currents for faster charging. At work I was running a cable out of the back door and into the car, however since the only way I could do that was by parking in my boss’ space I started parking out the front and running the cable through a window. Now that its cold this doesn’t go down too well, so I have installed a socket in a little shed we have out the back which I can connect to, and it has the advantage that I can lock the lid with my EVSE charger inside so it doesn’t get stolen (they are about £450!). I have an RSD on the inside where it is plugged in, in case of water ingress or vandalism.


I have also hunted high and low for a replacement battery for the lead-acid auxiliary battery, which seems the most unusual feature of such a modern car. This battery exists to power up the car and safely connect/disconnect the main traction battery. Lithium Iron Phosphate batteries around 20Ah capacity range from £120 to £850. I obviously opted for the £120 option and received it today from Germany, with a plug in mains charger to condition the battery (since regular lead-acid chargers are only partially suitable for charging LiFePo batteries, the issue is that they switch to trickle charging when the battery is full, which for a lead-acid is fine since they gradually discharge, but a lithium battery does not and is not able to absorb excess charge without serious problems, so lithium chargers cut off completely when the battery is full and only click on if it discharges, which takes a long time).

IMG_20141009_164839IMG_20141009_164848IMG_20141009_165750IMG_20141009_165927The first image shows the Lithium replacement battery which is about 1/3 the size of the car battery it replaces (stanley knife thrown in for scale). The other thing that is striking is the weight of the replacement battery which is just 3.2kg instead of 12kg for the lead acid. In order to install it I will need to get some adaptors which make the terminals fit and make a waterproof enclosure for it, since it is going to live in the engine bay where the lead acid battery was originally. The lead acid battery will become the leisure battery in my camper van from now on.

I have also managed to find some lightweight wheels. This has again involved many hours trawling through the internet (its a chore that someone has to do). The reason this was not simple is that lightweight wheels are very expensive. I have managed to find 4 Toyota Supra Mk1 wheels which apparently weigh in at 6kg a piece (saving 4-5kgs on the standard wheels) and the best bit they are only £60 (£100 delivered). This should save me 20kg of rotating unsprung mass, which is the equivalent to 80kg saved from anywhere else on the car, the weight of a moderate-sized adult passenger. They are in need of a refurbishment but even once this is done they should still be a very good value set of wheels. Photos of them before refurb, afterwards and on the car will follow once its all sorted out.

Now all I need is to get the spoiler fixed (still waiting on the insurance from the car-wash, and I have a funny feeling I am going to be repeating that statement for a long time to come), and to move on to replacing the non-LED bulbs with LED’s where practicable.


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