LeftieBiker
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Re: Replace small 12v battery to regular one.

Sat Apr 13, 2019 12:05 pm

Leaf and many modern vehicles charge 12V battery to very optimal state of charge, around 80%.
Lead-acid batteries like to be at 100% state of charge, or as close to it as possible. 80% may be good for a lithium battery, but 80% on a LA battery will cause gradual but significant sulfation.
Scarlet Ember 2018 Leaf SL W/ Pro Pilot
2009 Vectrix VX-1 W/18 Leaf modules, & 3 EZIP E-bicycles.
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arnis
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Re: Replace small 12v battery to regular one.

Sat Apr 13, 2019 1:35 pm

Correct. Though charging to this high state of charge results in excessive gassing (electrolyte loss - aka water boils out).
Salt deposition starts at around 60%.
Keeping charging voltage up to around 80% state of charge does not result in excessive gassing.
Ideal window is narrow though definitely doable.
Short range EVs <30kWh -- Medium range: 30-60kWh -- Long range: >60kWh
Charging: Trickle <3kW -- Normal 3-22kW -- Fast 50-100kW -- Supercharging >100kW

powersurge
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Re: Replace small 12v battery to regular one.

Wed Apr 17, 2019 6:28 am

I don't seem to see the need to worry about the 12V battery. After 4+ years and 55K miles, my battery is perfectly happy with good voltage numbers. I don't see the 12v battery to be a "maintenance" concern for most drivers. Also, if you put the battery on a "battery tender", then you really will not have issues......

BUT....... You should open the battery and check the water level on the cells regularly... That will kill the Bat.

arnis
Posts: 957
Joined: Sat Jan 23, 2016 3:21 pm
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Leaf Number: 015896
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Re: Replace small 12v battery to regular one.

Thu Apr 18, 2019 7:22 am

Only if cells can be opened. Valve regulated battery with 13.0V charging voltage will not let electrolyte to evaporate nor boil even in hot weather.
Short range EVs <30kWh -- Medium range: 30-60kWh -- Long range: >60kWh
Charging: Trickle <3kW -- Normal 3-22kW -- Fast 50-100kW -- Supercharging >100kW

LeftieBiker
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Re: Replace small 12v battery to regular one.

Thu Apr 18, 2019 1:02 pm

arnis wrote:Only if cells can be opened. Valve regulated battery with 13.0V charging voltage will not let electrolyte to evaporate nor boil even in hot weather.
The North American Leaf 12 volt batteries use flooded cells that can (and should, annually) be opened.
Scarlet Ember 2018 Leaf SL W/ Pro Pilot
2009 Vectrix VX-1 W/18 Leaf modules, & 3 EZIP E-bicycles.
BAFX OBDII Dongle
PLEASE don't PM me with Leaf questions. Just post in the topic that seems most appropriate.

powersurge
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Re: Replace small 12v battery to regular one.

Mon Apr 29, 2019 10:25 am

arnis wrote:Only if cells can be opened. Valve regulated battery with 13.0V charging voltage will not let electrolyte to evaporate nor boil even in hot weather.
The only "sealed" 12v car batteries I have seen were the tiny GM with the little green sight glass (green when it was fully charged) in the 1970s.. All "NORMAL" 12 volts have either individual screw top plugs, or the have 2 sets of square covers that you pry open with a screwdriver...

Either way, you got to open up the plugs to clean the top of the battery and check the water levels every once in a while..

powersurge
Posts: 1414
Joined: Wed Oct 21, 2015 10:24 am
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Location: Long Island, NY

Re: Replace small 12v battery to regular one.

Mon Apr 29, 2019 10:26 am

powersurge wrote:
arnis wrote:Only if cells can be opened. Valve regulated battery with 13.0V charging voltage will not let electrolyte to evaporate nor boil even in hot weather.
..
The only "sealed" 12v car batteries I have seen were the tiny GM batteries with the little green sight glass (green when it was fully charged) in the 1970-80s.. All "NORMAL" 12 volts have either individual screw top plugs, or the have 2 sets of square covers that you pry open with a screwdriver...

Either way, you got to open up the plugs to clean the top of the battery and check the water levels every once in a while...

GerryAZ
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Re: Replace small 12v battery to regular one.

Mon Apr 29, 2019 9:32 pm

AGM and VRLA (absorbed glass mat and valve-regulated lead acid) batteries are sealed, but have a pressure relief valve to release excess pressure if they are overcharged. If they are overcharged frequently, they eventually lose electrolyte and fail because there is no realistic way to refill them. They generally last much longer than conventional batteries if they are never overcharged.
Gerry
Silver LEAF 2011 SL rear ended (totaled) by in-attentive driver 1/4/2015 at 50,422 miles
Silver LEAF 2015 SL purchased 2/7/2015; traded 8/10/2019 at 82,436 miles
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