Battery PreConditioning - Battery Life

I am a 5 year i3 owner. I have just seen a post on another forum that suggests that battery pre-conditioning is essential to battery long term life. I will put my 'hands up' and say that most of my 60Ah i3 journeys were runs out locally. If range wasn't an issue, then I would take the car cold. When I sold my first i3 after 4 years, the summer range was little changed from new. Have I missed out on a vital part of my i3 education?

New 2017 i3 owner here, I have had the car for 2 months.

This is a good question indeed. I assume you live in a cold weather area.

I'm in Illinois and have been wondering if one needs to do conditioning year around? I of course, do it on cold days here because it's nice to have the car warm.
Does it need to be done (conditioning for battery health) when the temp is 60 degrees plus?

Hengus said:

... a post on another forum that suggests that battery pre-conditioning is essential to battery long term life.

Click to expand...

Care to cite that source? I'm not agreeing or disagreeing, but the sharing of information is good. My general understanding of it is that high temps will degrade a battery, which in use is a chemical reaction. At low temperatures, the reaction process slows, and batteries become inefficient i.e. lower driving range, but I haven't seen anything claiming this has an adverse effect on overall life.

More the opinion of a poster than a reliable source. He was annoyed that his very clever charging point can cope with him setting a cheap ToU 30 minute* cost to charge his i3 but cannot cope with battery pre-conditioning which, in his opinion, is vital to long term battery life. I confess that this was a new one on me.

*In the UK, one supplier is offering what is known as an Agile tariff with 30 min prices. For the past 2 days, with reduced electricity demand due to CV19, and sun plus wind, customers are being paid to use electricity at certain times of the day. The smart charger takes in 30 minute price/kWh data from the supplier, and the end user can set a maximum price. The car will only charge when the price is below the set level.

Just so there isn't any confusion, conditioning the batteries does not mean preconditioning the cabin. They can be done in the same operation, but each can be done separately (although you can't use the menu to precondition the cabin separately)...

It's harder to move electrons when the battery is cold, so to achieve maximum range, it's good to prewarm them. Depending on the ambient conditions, that can take over 3-hours whereas, conditioning the cabin will only run for about 30-minutes, and at the end of the battery warming cycle, if you've selected that. If your goal is maximum range and comfort, then precondition the batteries and the cabin so the batteries can move those electrons easier and you aren't using power from the battery to warm the cabin when you start.

Should you need the maximum warming, that heater is a 1Kw device, and could be running the full 3-hours. Often, it won't be that long, but it could be.

When conditioning the batteries and warming the cabin, I've seen my EVSE pulling over 20A, or at 240vac, about 4800W. Now, it's not doing that the entire time. So, there's an energy cost to that extra range and comfort. Depends on your needs whether it's worth it. Since you're literally starting with less usable capacity when it's cold out, you're more likely to get your final SOC lower, which may affect longevity. IMHO, it's not the fact that it's cold, but the ultimate SOC you have when you're done, and it's lower if you don't set a departure time and condition the batteries. The more often you get the SOC low, the more wear on the battery. If you can limit that by preconditioning them, you won't have as deep a discharge on the same trip. Probably makes no difference in your typical summer, but if it's cold where you live, it could.