leaf 12 Battery Power usage

[voiceexp]

Hi, I am a Nissan Leaf owner. Can anyone tell me what the 12volt battery powers in the car?

I thought it powered the wind screen wipers but when driving in the rain the wipers used the lithium battery power.

Regards, Conrad

 

[MikeD]

My simplistic understanding is that the DC-to-DC converter which is powered by the lithium-ion battery pack constantly charges the 12v battery when the Leaf is in Ready Mode, and the power output from the converter increases when needed, drawing current from the battery pack (which shows in fluctuations in the "MENU/Energy Info. -- Other Systems" display in step with wiper activation). In a normal non-EV does one say the 12v battery powers the wipers or the alternator while driving? I think it is a similar situation as in an EV.

 

[TomT]

It powers basically everything except the motive drive system, AC and Heater...

Hi, I am a Nissan Leaf owner. Can anyone tell me what the 12volt battery powers in the car?

 

[Iowa92x]

Why does the LEAF need a 12v DC battery?

 

[DeaneG]

Why does the LEAF need a 12v DC battery?

So that Nissan could quickly develop an EV using existing technology (radio/nav, electric steering, etc) without also having to build and debug a low quiescent power consumption high-peak-power HVDC/12vDC converter. It's a choice.

It's not the coolest solution, but does let Nissan lever from their hybrid engineering experience, and incur the least development schedule risk and engineering resource usage.

 

[toasty]

how much does the solar cells on the roof, charge the 12v battery?

 

[JeremyW]

how much does the solar cells on the roof, charge the 12v battery?

5 Watts in direct sunlight. A pittance.

 

[DarkStar]

Why does the LEAF need a 12v DC battery?

It's for safety. Having a separate 12 volt battery allows the high-voltage traction pack to be typically disconnected unless certain functions are going on.

 

[Nubo]

Why does the LEAF need a 12v DC battery?

So that Nissan could quickly develop an EV using existing technology (radio/nav, electric steering, etc) without also having to build and debug a low quiescent power consumption high-peak-power HVDC/12vDC converter. It's a choice.

Yep, they can use a cheaper DC-DC converter. Also, a 12V battery gives you power in emergency situations, emergency flashers, etc., even if the traction pack or electronics are disabled or you have driven past Turtle mode and the main pack contactors have opened.

 

[toasty]

how much does the solar cells on the roof, charge the 12v battery?

5 Watts in direct sunlight. A pittance.

wow. only 5 watts?

has anyone put a multimeter to it to confirm?

 

[adric22]

Yeah. I think it is a good idea that everything runs on 12V except for those things which require the higher voltage. I suspect it is much safer and more cost effective. Can you imagine if they had to re-design every light bulb, wiper motors, computer systems, etc... to run on the higher voltage.