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garygid
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Re: How is the 12V battery recharged? Max amperage?

Sun Mar 11, 2012 9:29 am

What does the LEAF do at the 50-minute mark if the 12v battery has been disconnected for charging?

Probably nothing, since most of the control electronics ...
has no 12v power, so it cannot time the 50 minutes?
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TonyWilliams
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Re: How is the 12V battery recharged? Max amperage?

Sun Mar 11, 2012 9:53 am

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garygid
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Re: How is the 12V battery recharged? Max amperage?

Sun Mar 11, 2012 12:02 pm

Basically these instructions seem to say that after the LEAF is:

1. turned OFF
2. not connected for charging
3. not doing Climate Control
4. with all doors and hatch shut

Wait 5 minutes.

Then, disconnect the 12v battery anytime in the next 50 minutes.

No caution (IMO) about leaving the 12v battery disconnected for a "longer" time.
See SOC/GID-Meter and CAN-Do Info
2010 Prius, now for sale
2011 LEAF, sold in 2015
2018 Tesla Model 3
2014 Tesla S, Model 3 in 2019
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TonyWilliams
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Re: How is the 12V battery recharged? Max amperage?

Sun Mar 11, 2012 1:53 pm

garygid wrote:No caution (IMO) about leaving the 12v battery disconnected for a "longer" time.


Only caution is that it may charge, even when the car is off and all the requirements met to remove the battery. So, does that mean the 12 volt lead is "hot" from the DC/DC converter at the post hour mark from "Off", while the traction battery is trying to charge the missing battery?

Not really clear.

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garygid
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Re: How is the 12V battery recharged? Max amperage?

Sun Mar 11, 2012 11:05 pm

Once the 12v power is removed, and stored charge (on capacitors)
is gone, it is unlikely that the car can come "alive" enough to be able
to operate the DC-to-DC converter.

So, I suspect that a certain minimum voltage on the "12v buss"
is required for the LEAF to do anything, even try to charge the 12v battery.
See SOC/GID-Meter and CAN-Do Info
2010 Prius, now for sale
2011 LEAF, sold in 2015
2018 Tesla Model 3
2014 Tesla S, Model 3 in 2019
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DaveEV
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Re: How is the 12V battery recharged? Max amperage?

Mon Mar 12, 2012 12:21 pm

garygid wrote:Once the 12v power is removed, and stored charge (on capacitors)
is gone, it is unlikely that the car can come "alive" enough to be able
to operate the DC-to-DC converter.

So, I suspect that a certain minimum voltage on the "12v buss"
is required for the LEAF to do anything, even try to charge the 12v battery.

Yep. Once you've removed the battery (between 5 min and 60 min after having turned the car on/off and not opening any doors) you don't need to worry about hooking the battery back up within an hour.

The precautions are around removing the 12v battery while it may be trying to charge the 12v battery. As long as the 12v battery is removed the car, the car is effectively dead. The high voltage battery isn't used for anything in that state and is effectively disconnected until the 12v battery is reconnected.

CWO4Mann
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Re: How is the 12V battery recharged? Max amperage?

Mon Mar 12, 2012 6:12 pm

garygid wrote:The 12v battery is only "charged" when the LEAF is ON. Then the high-voltage (300 to 500 volt?) DC to 12 volt (nominal) DC converter might be capable of supplying 100 amps (or so).

However, that would be "using the LEAF's (main) battery" as a "power source", which is listed by Nissan as a "prohibited" (or "not covered"?) use.



And you would, of course, tell the dealer's service manager that "Dern, I sure did done voided the warranty yesterday .. hooked up the whole neighbor hood to my Leaf and watched the spark fly".

I am hoping -- no, praying -- that we have not gotten so far into cringing correctness that we feel forced to "tell the truth". I for one wouldn't tell the dealer the time of day if it were high noon, there was a solar flare and the building he was in was next door to a Chinese Firecracker Factory with a failed OSHA record.

If you are attaching the inverter using the existing battery nuts and bolts, there won't even be any scratches form the alligator teeth of the clamps.

Dealer axe me "why your battery all melted and stuff?" I say, dang, I don't know .. I was watching porn on the Carwings Screen.
Ira est potens et pertinax.
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ht2
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Location: Silicon Valley, CA

Re: How is the 12V battery recharged? Max amperage?

Mon Mar 12, 2012 7:12 pm

garygid wrote:The 12v battery is only "charged" when the LEAF is ON. Then the high-voltage (300 to 500 volt?) DC to 12 volt (nominal) DC converter might be capable of supplying 100 amps (or so).

However, that would be "using the LEAF's (main) battery" as a "power source", which is listed by Nissan as a "prohibited" (or "not covered"?) use.


When the Leaf is ON, DC-DC converter is always on and supplying 13.5V or Turn on only when 12V battery is low?

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TonyWilliams
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Re: How is the 12V battery recharged? Max amperage?

Mon Mar 12, 2012 7:22 pm

ht2 wrote:
garygid wrote:The 12v battery is only "charged" when the LEAF is ON. Then the high-voltage (300 to 500 volt?) DC to 12 volt (nominal) DC converter might be capable of supplying 100 amps (or so).

However, that would be "using the LEAF's (main) battery" as a "power source", which is listed by Nissan as a "prohibited" (or "not covered"?) use.


When the Leaf is ON, DC-DC converter is always on and supplying 13.5V or Turn on only when 12V battery is low?


Automatic charge control does not start until approximately one hour after car is turn OFF, per the note from the Nissan Service Manual posted several posts up.

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DaveEV
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Re: How is the 12V battery recharged? Max amperage?

Mon Mar 12, 2012 8:10 pm

ht2 wrote:When the Leaf is ON, DC-DC converter is always on and supplying 13.5V or Turn on only when 12V battery is low?

Yes, when the LEAF is on it will always supply ~13.5v to make sure the 12v battery is charged.

Edit: Actual voltage is closer to 13.0V, not 13.5V.
Last edited by DaveEV on Sat Apr 18, 2015 8:30 pm, edited 1 time in total.
Reason: Corrected voltage.

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