Used Peugeot iOn review and buying guide (2010 to 2018): which one to buy and what to check

Which used Peugeot iOn should you buy?

Buy the iOn with the healthiest battery, whatever its year, because the pack decides whether the car's worth keeping. In 2019 Peugeot told one owner the only fix for his car's battery was a new battery at £12,000, which left the car effectively written off. He couldn't get the control codes to rebuild it from the cells that still worked, so don't count on a cheaper repair.

Rust is the other deciding point. The light body is prone to corrode along the front edge of the bonnet and on the rear wings after 8 to 9 years, and with the iOn gone from sale in 2018, every one you'll find is at least 8 years old. Favour a car with clean wings and bonnet edges, and treat bubbling paint there as rot that's already started.

Which Peugeot iOn battery and motor is the safer choice?

There isn't a safe or unsafe iOn battery, only a healthy or a worn one. Cars from before summer 2012 carry a 16 kWh pack of 88 cells; from summer 2012 Peugeot switched to a 14.5 kWh pack of 80 cells, while the Mitsubishi i-MiEV twin kept the larger one. An early car starts with more capacity, but that counts for nothing if its cells are tired.

The cells also changed to a revised LEV50N chemistry with an electrolyte that copes better with heat. Peugeot said at the time that range hadn't dropped because regenerative braking had got more efficient, though the new cells were the real reason. Nothing shows the later cells lasting longer in real use, so don't choose a later car on that basis alone.

The one drivetrain problem on record is a recall. On a small batch of cars built in 2011 and 2012, the engine control unit could malfunction and cut power, and the fix was a replacement control unit. If the car you're looking at is from those years, ask for proof the work was done.

What should you check when viewing a used iOn?

Check the battery before anything else. Ask the seller to have it fully charged when you arrive, then watch how quickly the charge gauge falls on a proper test drive, including some faster roads. A pack that drains fast isn't something to take on, since it's the expensive failure on this car, and a 2013 Citroen C-Zero, the iOn's sister under another badge, had its battery fail completely.

Get down and look along the front edge of the bonnet and at both rear wings for bubbling paint or rust. On a 2011 or 2012 car, ask for the paperwork showing the engine control unit was replaced under the recall, and on the drive, note any sudden loss of power.

One owner found their car slow, rattly, hard to demist and pushed about by side winds, and its windscreen cracked overnight on its own. Check the screen for cracks, run the demister and listen for rattles over bumps. That owner also found only a thin strut behind the rear bumper, so after any rear knock, look underneath for damage near the motor.

Paste the advert into the free check and it runs these against the listing, the MOT history and the DVLA record before you travel.