quick question about the 12 volt battery in the PHEV cargo area...
what does it do ? I have an 2018 HEV and it does not have one because it is placed next to the full battery under the back seat.
Thanks.!
It does everything that a 12V would do in a normal car. virtually every switch or piece of electronics in the world for a car is 12v so the car needs to have a 12v power source. In the HEV version a first ever integrated 12v lithium ion 'battery' (which is just a partition of the big battery) is there but on the phev they wanted all the lion battery space for range. All other hybrids and EVs up to now have always had a 12v battery separate from the main battery.
A big revolution in electronics is happening though in cars. 48v hybrids are coming. Several are already rolling out in things such as US made pickup trucks. Huge advantages and cost savings for these 'mild' hybrids. Why?
1. 12v systems are being stretched to the max as far as power supplied as more and more stuff becomes electronic.
2. The extra power available via 48v systems allows numerous things to be done that will create higher efficiency at a low price point. e.g. electronic superchargers, electronic oil and water pumps, smart alternators/regen that provide about 15HP boost at low RPM which is a double whammy increase to power/efficiency because this also means during acceleration, the parasitic losses from belt/mechanical driven items is removed and run off stored power...water pumps, oil pumps, etc. Same thing for electrical loads (hvac, headlights, etc) during acceleration. So remove parasitic losses (several horsepower) while adding in 15-20hp of boost by switching to motor not generator (and even more torque) is a huge net plus which allows smaller engines as well as different engine cycles (such as Atkinson cycle) and leaner fuel mixtures. But wait....isn't that the same principal as a regular hybrid? yes but......
3. 48v systems are not considered 'high voltage'. A 'regular' HEV is considered high voltage. As such numerous special precations are taken by regulation which add large amounts of expense and weight. For example the cabling in high voltage is much heavier. 48v systems can provide a tamed down hybrid without the weight and price penalties associated with high voltage systems.
4. the increased power from the 48v systems can make for much smoother start/stop systems. The motor replaces the standard starter and can spin up the engine quicker/more smoothly and combined with the power assist make a seemless launch whereas start/stop systems to date have been annoying at best.
There are several coming on the market in 2019. The articles from the LA auto show are a bit fuzzy on details but it looks like the new Mazda 3 later in the year will combine this with also first ever compression ignition to get a car that is as efficient as a Prius without having a full blown hybrid. The articles are a bit contradictory sometimes though and some speak of i-eloop which is an ultracapacitor system previously used and in other places the articles refer to the new lithium ion light hybrid 48v system. It's not obvious to me if the car will have both or whether the 48v hybrid is the replacement to the i-eloop. Both would be cool.
I've read that a 48v hybrid system gets you about $500 net increase in cost but can add a very large amount to combined mileage. Top bang for the buck.