I have a Clarity plug in 2018 with about 60,000 miles. I am using level 2 charging. I am getting fully charge message but the range is keep dropping. It is now at 36 miles. I took it to two different dealerships but they could not find the cause. The battery has a 10 year’s warranty but they did not point to possible battery. They have no clue. I even called the Honda corporate but they just refered me to my local dealership.
I would appreciate your inputs.
What you're reporting seems pretty normal, for this time of year.
Lithium batteries have a widely known issue when operating at low-temperatures. They effectively temporarily lose capacity when the cells are cold. Their ability to provide (discharge) and accept (charge) energy at low temperatures is also reduced.
In addition, the heating system is not very efficient. (It's not a heat pump.) To keep warm in winter, we typically uses the cabin heater much more.
So, in cold weather, we get the double-whammy of reduced effective battery capacity, and high energy use to keep the cabin warm. The result is often a 10-40% hit on electric range, depending on how cold the weather is. This isn't just an issue with the Clarity batteries. Battery electrics (BEVS) take a significant hit in range when it's cold. I also drive a Bolt, and those with Bolts in the North (where temps are often below freezing) commonly report a 40% range hit.
There are other issues that can affect range as well:
- Changing the tires to a non-LRR type. The OEM tires on the Clarity were specifically picked (designed?) to minimize rolling resistance, and thus maximize efficiency. Changing to winter tires will probably reduce range, and in fact, changing to any tires that are not the same as the OEMs will probably decrease range.
- Rain and snow. The tires are pushing water or snow out of the way when rolling. This can significantly reduce range.
Others here have also reported range losses as the batteries age. This, too seems to be pretty normal, but I suspect that most of your issue is with the cold.
Also, if you're depending on the GOM (Guess-O-Meter) to give accurate results...there's a reason it's called a "Guess-O-Meter". It's a guess, based on previous driving style.