On 19/10/2017 15:55, harry wrote:
On Thursday, 19 October 2017 13:44:07 UTC+1, Bill Wright wrote:
On 19/10/2017 09:03, T i m wrote:
On Thu, 19 Oct 2017 08:21:49 +0100, "Brian Gaff"
wrote:

What happens if he needs the heater and the wipers etc as well though?

On my EV there is no heater and the wipers and lights etc run from an
independent auxiliary battery so wouldn't affect the range as such,
especially in the dry and daytime. ;-)

Cheers, T i m

So on a long journey in the rain the wipers and lights would pack up?
What's the capacity of the aux battery? Normal wipers draw between 5 and
10A at 12V so you'd need a big ass battery to keep then working all day
long.

Bill

It's charged from the traction battery.
It's a tiny battery. (No starter motor)
If it goes flat, the car can't be charged, run or anything.


But you can then recharge the 12V battery as normal with a normal car
charger and recover the situation.

The one thing that I will say is the biggest weakpoint at the moment in
EV's IS the 12V battery.
In a Zoe (yawn) the 12V battery is normally replaced every 3 years as
part of the service schedule to prevent being caught out with a failed
battery. As I have said elsewhere if the battery is functioning normally
it is normally continuously being recharged from the traction battery
via a DC/DC converter.

Current (no pun) lead acid batterys used in EV's are standard legacy
vehicle type batterys, and tend to fail early as the lead plates
sulphate up over time - an EV does not have a high current starter motor
being used several times a day to cause the plates to self clean.
Hence the battery fails in lesser time than you would expect.

The 12V battery is there to brovide a keep alive voltage for the cars
main contactor - the 400V traction battery is normally completely
disconnected when the car is 'turned off'.

The 12V supply being used to power the main 400V traction contactor on
startup, and power light/radio and othe low power stuff when the
'engine' is off