Comment by MBCook
15 days ago
Do they?
I was under the impression most EVs cut off the connection to the high voltage battery almost all the time they’re not in use.
They rely on a 12 V battery or a 48 V battery like a normal car.
The only thing I’m aware of that special is that if that low voltage battery gets low enough the car will detect it and recharge it from the high voltage battery, temporarily connecting it for that purpose.
> They rely on a 12 V battery or a 48 V battery like a normal car.
Which leads to "fun" situations when that battery runs out, like not being able to get into your car or start it. However not much power is needed, so a tiny portable jump pack is enough to get things going.
Both me and my sister has experienced this, me a Nissan Leaf and her a VW ID.4, good times.
Both my old Bolt and Ioniq 5 had alternate key entry systems in the door handles.
Fair enough, at least my Leaf had that too, and I guess the ID.4 as well. However for the Leaf and my current car it's just the driver side, and you still can't get the car started, or turn on the heat say.
The latter can be an issue as my sister got stranded in the mountains during winter. Battery ran flat while they were on a long ski trip, and they couldn't get it fired up when they got back. Took a few hours before rescue vehicle arrived and gave them a boost.
I have too. Mach-E.
Well that was what I meant - the battery pack meaning the entire system of batteries, be it 1 or 2 or 3.
That really enables them to have a continuous state of power supply for a long long time. This cannot be achieved by ICE cars and not even hybrids for that matter.
In theory. In practice, a lot of EVs (and hybrids, which could do the same thing to a more limited extent) ship with the same cheap flooded lead acid 12v batteries that ship with ICE cars and don't handle constant charging/discharging well.
This puts a cap on how much the "smart" systems can do because it dramatically increases cycle count and thus the risk of the 12v battery losing the ability to produce enough voltage to start the car, leaving the driver marooned somewhere.
It could also result in a noticeable "vampire" drain on the high voltage battery which looks bad and could put you at a disadvantage vs. competitors.
My EV also has an extra-tiny 12V battery because it doesn’t need to crank anything over.
So extra drain would be an extra big problem.