6 ms·
If you don't have a way of charging the battery, it's less efficient than if it were gas-only.
by kenhwang 3y ago
If you don't have a way of charging the battery, it's less efficient than if it were gas-only.
- hunter2_ 3y agoBraking is a way of charging it that everyone has.
- MBCook 3y agoOver time you can never get more energy from braking than you spent accelerating. A larger battery won’t do you any good if charged by regeneration unless you’re somehow always driving down a big hill. There’s a reason hybrids like the non-PHEV Prius models have tiny batteries.
- omgwtfbyobbq 3y agoIt helps a fair bit. The regen in my first Gen Insight is worse than in my second Gen Prius, which is worse than the regen in my first Gen plug-in Prius, which is worse than my Model 3. At some point, the extra weight cannot be offset by more/better Regen and better fuel efficiency on gas where applicable, but going from a few kWh hybrid to a 10-20 kWh hybrid will usually be a net positive even with additional weight, all other things being equal.
- adgjlsfhk1 3y agoReally? Why? adding a plug adds a couple pounds but other than that, the plug is neutral and the battery is a win since regenerative breaking is really useful.
- kenhwang 3y agoBatteries are heavy, and even the weight for a modest sized (15-20kWh) one used for a PHEV is heavy enough (+500-700lbs) to impact the fuel economy enough where it is a net negative even accounting for regular hybrid recharging/regen braking. You're better off with a significantly smaller regular hybrid battery (1-2kWh) or none at all instead of lugging around the weight of a discharged PHEV battery that'll never reasonably be close to charged from regular driving (unless your regular driving includes ~200 miles only steep downhill braking to fully charge the PHEV battery).
- greesil 3y agoBut wouldn't aggressive regenerative braking negate the weight penalty? The hybrid Toyotas I've driven are pretty weak here, but the Chevy Bolt I drove had very strong regenerative braking. As for cost, well, that's what the subsidies are for.
- kenhwang 3y agoA Prius Prime has a 161HP/120kW electric motor and a 13.6kWh battery. Regen braking is usually able to capture 15-30% of the motor's output power. You'd have to be at full regen for about 22 minutes to fully charge that battery. That's not a realistic driving pattern for a significantly large majority of people.
- omgwtfbyobbq 3y agoPHEV batteries aren't that heavy these days. The Prius Prime has ~14kWh battery and weights ~290lbs. https://www.sae.org/news/2023/04/2023-toyota-prius-prime-drive https://www.sae.org/news/2023/04/2023-toyota-prius-prime-dri... Even with an extra 200+lbs, having a bigger battery is better for Regen and offsets the additional weight to some extent. If someone is a super conservative/disciplined driver, they can get the same mpg from a hybrid with a smaller pack, but most people don't want to hypermile their cars.
- jacquesm 3y agoThat is a lot of weight to add to a vehicle, don't forget that every time you accelerate you need to accelerate that weight too.
- adgjlsfhk1 3y agosure, but 90% of a car's energy goes towards fighting air resistance which doesn't change at all. (and ~20% of the ~10% energy penalty for accelerating gets returned when you brake)
- 3y ago
- tshaddox 3y agoPHEVs have much larger batteries than HEVs.
- culopatin 3y agoSo if I put the engine of a Prius connected to a manual transmission you say that over 100 miles of mixed use I’ll get better gas mileage? Why?
- timbit42 3y agoThat is false. A Prius is a HEV and can't be charged and mine uses 40% less fuel than a similarly sized gas vehicle. Additionally, a PHEV typically gets at least 30% better fuel economy than a gas vehicle.