frontrangeleaf
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Location: Denver Area

Re: DIY 12v Battery Change

Wed Apr 08, 2020 8:58 am

One note: a 12v battery replacement on a BEV capable of starting a charge session from the traction battery to the 12v is a different animal from a conventional vehicle - we don't normally replace a starter battery on a conventional vehicle with it running and the alternator providing a charge.

If the OP's instructions are true regarding a 12v charge session possibly starting unexpectedly, the "off-on-off" sequence to disable said charge for an hour might be of interest. At least as an edge case. I don't think there's enough amperage to be a concern, and 12v isn't enough to push a current through your body barring extenuating circumstances (hands wet, standing in a puddle) but it is a difference to the norm most folks know.

I would say, don't make this harder than it is. Disable the 12v charge option as described, swap out your battery with a suitable replacement, make sure your terminals have a good connection, and consider a coating with a dielectric as suggested above. No biggie.
Empty-nesters - NW Denver-Boulder Area

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lorenfb
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Re: DIY 12v Battery Change

Wed Apr 08, 2020 10:21 am

powersurge wrote:
Wed Apr 08, 2020 4:24 am

Remove the black negative cable and then the red positive cable.
It doesn't matter, i.e. the electrons don't care.
#1 Leaf SL MY 9/13: 76K miles, 47 Ahrs, 5.0 miles/kWh (average), Hx=70, SOH=73, L2 - 100% > 1000, temp < 95F, (DOD) > 20 Ahrs
#2 Leaf SL MY 12/18: 10.3K miles, SOH 109Ahrs/115Ahrs, 5.2 miles/kWh (average), DOD > 20%, temp < 105F

goldbrick
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Re: DIY 12v Battery Change

Wed Apr 08, 2020 10:29 am

It matters only in that the car body is grounded to the negative terminal of the battery. If the wrench hits the body of the car while disconnecting the positive cable end before the negative cable is disconnected, it will short out. If the negative terminal is disconnected first this isn't a problem. If the wrench hits the body of the car while disconnecting the negative cable first it is is also fine. So it's a bit safer to disconnect the negative terminal first.

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mwalsh
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Re: DIY 12v Battery Change

Wed Apr 08, 2020 11:14 am

lorenfb wrote:
Wed Apr 08, 2020 10:21 am
powersurge wrote:
Wed Apr 08, 2020 4:24 am

Remove the black negative cable and then the red positive cable.
It doesn't matter, i.e. the electrons don't care.
Not true. Old school wisdom - disconnect earth lead first, reconnect last. Only place lead color applies is on the rarity that is the positively earthed vehicle (ie: MGs before 1968).
2011 Blue Ocean SL with 86,000 miles
2015 pack on 12/30/15
Tinted windows
Bosch AGM 12v
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LED shifter
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Altima illuminated door switches

lorenfb
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Re: DIY 12v Battery Change

Wed Apr 08, 2020 8:41 pm

mwalsh wrote:
Wed Apr 08, 2020 11:14 am
lorenfb wrote:
Wed Apr 08, 2020 10:21 am
powersurge wrote:
Wed Apr 08, 2020 4:24 am

Remove the black negative cable and then the red positive cable.
It doesn't matter, i.e. the electrons don't care.
Not true. Old school wisdom - disconnect earth lead first, reconnect last. Only place lead color applies is on the rarity that is the positively earthed vehicle (ie: MGs before 1968).
Laughable, that's mentioned! If one is incapable of properly using tools, take it to a Nissan dealer. Besides some have a problem
determining the positive from the negative terminal (no red cable or poorly marked posts), resulting in damage to the vehicle's
electrical system when installing the replacement battery.
#1 Leaf SL MY 9/13: 76K miles, 47 Ahrs, 5.0 miles/kWh (average), Hx=70, SOH=73, L2 - 100% > 1000, temp < 95F, (DOD) > 20 Ahrs
#2 Leaf SL MY 12/18: 10.3K miles, SOH 109Ahrs/115Ahrs, 5.2 miles/kWh (average), DOD > 20%, temp < 105F

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mwalsh
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Re: DIY 12v Battery Change

Thu Apr 09, 2020 3:40 am

lorenfb wrote:
Wed Apr 08, 2020 8:41 pm

Laughable, that's mentioned! If one is incapable of properly using tools, take it to a Nissan dealer. Besides some have a problem
determining the positive from the negative terminal (no red cable or poorly marked posts), resulting in damage to the vehicle's
electrical system when installing the replacement battery.
I don't know what's laughable about it - I'm saying that in some (admittedly rare) instances you aren't going to see a black cable at the negative terminal and a red one at the positive terminal. You've as much as said the same yourself right here.

And the reason you disconnect the earth lead first is so that you don't accidentally short the other terminal to the car body while the battery is still grounded. Not only do you short your battery out, but you end up welding whatever metal object you dropped between the two to that panel. And I didn't notice this until just now, but goldbrick says the same thing.

But, you know, you take care of your shit the way you want and I'll do likewise.
2011 Blue Ocean SL with 86,000 miles
2015 pack on 12/30/15
Tinted windows
Bosch AGM 12v
Ecopia 422+ tires
L1 EVSE upgrade
FIAMM horns
Superbright LED lighting
2013 sun visors
LED shifter
Heated seats
GT-R map lamp lenses
Altima illuminated door switches

LeftieBiker
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Re: DIY 12v Battery Change

Thu Apr 09, 2020 3:54 am

It's sound advice to disconnect the negative cable first in negative ground vehicles. Some people just have trouble admitting a mistake.
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PLEASE don't PM me with Leaf questions. Just post in the topic that seems most appropriate.

lorenfb
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Re: DIY 12v Battery Change

Thu Apr 09, 2020 9:29 am

LeftieBiker wrote:
Thu Apr 09, 2020 3:54 am
It's sound advice to disconnect the negative cable first in negative ground vehicles.
For some that typically use the wrong tool for the application! Also not helpful for those that can't correctly identify the negative terminal.
Last edited by lorenfb on Thu Apr 09, 2020 10:07 am, edited 1 time in total.
#1 Leaf SL MY 9/13: 76K miles, 47 Ahrs, 5.0 miles/kWh (average), Hx=70, SOH=73, L2 - 100% > 1000, temp < 95F, (DOD) > 20 Ahrs
#2 Leaf SL MY 12/18: 10.3K miles, SOH 109Ahrs/115Ahrs, 5.2 miles/kWh (average), DOD > 20%, temp < 105F

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mwalsh
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Re: DIY 12v Battery Change

Thu Apr 09, 2020 10:06 am

lorenfb wrote:
Thu Apr 09, 2020 9:29 am

For some that typically use the wrong tool for the application!
Oh, give it up. You can try to justify it all you want. But your "advice" is bullshit.
2011 Blue Ocean SL with 86,000 miles
2015 pack on 12/30/15
Tinted windows
Bosch AGM 12v
Ecopia 422+ tires
L1 EVSE upgrade
FIAMM horns
Superbright LED lighting
2013 sun visors
LED shifter
Heated seats
GT-R map lamp lenses
Altima illuminated door switches

lorenfb
Posts: 2428
Joined: Tue Dec 17, 2013 10:53 pm
Delivery Date: 22 Nov 2013
Leaf Number: 416635
Location: SoCal

Re: DIY 12v Battery Change

Thu Apr 09, 2020 10:13 am

mwalsh wrote:
Thu Apr 09, 2020 10:06 am
lorenfb wrote:
Thu Apr 09, 2020 9:29 am

For some that typically use the wrong tool for the application!
Oh, give it up. You can try to justify it all you want. But your "advice" is bullshit.
Typical for some, an ad hominem!
#1 Leaf SL MY 9/13: 76K miles, 47 Ahrs, 5.0 miles/kWh (average), Hx=70, SOH=73, L2 - 100% > 1000, temp < 95F, (DOD) > 20 Ahrs
#2 Leaf SL MY 12/18: 10.3K miles, SOH 109Ahrs/115Ahrs, 5.2 miles/kWh (average), DOD > 20%, temp < 105F

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