Is there any reason not to charge your EV battery all the way to 100%?
Ford includes a buffer in the battery. Charging from 0 to 100 only uses 10 kWh of the 12 kWh capacity.
Amara said:
Ford includes a buffer in the battery. Charging from 0 to 100 only uses 10 kWh of the 12 kWh capacity.
I think it’s 14 kWh, but yeah, the most I’ve seen go in is 11.5 kWh.
Short answer: it’s fine. When the display shows 0% or 100%, the car actually charges to around 91% and drains down to 17% to preserve battery life. Long answer: EV batteries perform best when charged between 40% and 60%, but if you only used that range, you’d need a much larger battery. Ford’s design is a balance between battery size, cost, range, and longevity. So, you can charge and discharge as needed. Just avoid leaving it at 100% for a long time, like weeks, without driving.
In some cases, charging to a lower limit might be better. If you don’t drive much, say less than 20 miles daily, charging to 80% could be more efficient, as the car works better in stop-and-go traffic with less than 80% charge. Also, charging up to 90%-95% is cheaper and more efficient since the rate slows down at the end. For long-term storage, the car should be at 50%. If you’re driving long distances like I do daily, it’s better to just charge to 100%. The car’s 100% is actually around 90% of the total battery charge.
@Ava
Why is the car more efficient at a lower state of charge?
Hayley said:
@Ava
Why is the car more efficient at a lower state of charge?
Well, the efficiency comes from regenerative braking. When the battery is at 100%, no regeneration happens. As the charge drops below 100%, regeneration kicks in more effectively. In some driving conditions, like stop-and-go traffic, you’ll recover more energy from braking, which is why it’s more efficient to charge less. But if you’re driving on highways, like I do, regeneration doesn’t make much of a difference.
@Ava
I see, so you’re saying regeneration only makes a big difference in stop-and-go traffic?
Hayley said:
@Ava
I see, so you’re saying regeneration only makes a big difference in stop-and-go traffic?
Exactly. In city traffic, where you stop and start often, regeneration can really help save energy. But for most other types of driving, it’s a small factor. It’s important to know that regeneration can never recover as much energy as it consumes, but it’s still better than using friction brakes. For someone with a short commute in traffic, they might actually use less energy by charging to 80% instead of 100%.
@Ava
That makes sense. I was confused about how regen works, especially with hybrids.
Hayley said:
@Ava
That makes sense. I was confused about how regen works, especially with hybrids.
Hybrids are a bit different. When their battery hits a certain level, the engine kicks in to burn off the excess energy. But with EVs, they only regenerate power if the battery isn’t full. Between 80% and 100%, the car allows more regeneration in steps, and it opens up more as the battery charge drops below 80%.
Nope, it’s fine to charge to 100%.
TLDR; it’s probably fine to charge to 100%. Charging to 90% or higher can reduce regenerative braking, and the battery might degrade faster, but the effect is small in the long run. If you’re worried about battery life, charging to 85% might be better, but it’s not a huge deal. Charging above 90% reduces regen, but the battery’s actual charge is only about 92%. Ford has a buffer to lessen the degradation. My personal advice is to charge to 85%, unless you really need the full 100%. For daily driving, I usually charge to 85% and top it off to 100% in the morning when I need to.
@Gregory
Regen is already limited above 80%. Above 95%, it’s nearly nonexistent. Only below that does it make a significant difference.