grnbrg
Posts: 2
Joined: Fri Aug 03, 2018 7:02 am
Delivery Date: 27 Jul 2018
Leaf Number: 313124
Location: Winnipeg, Canada

Re: Solutions to 12 Volt Batteries and Chargers Posted Here

Thu Aug 16, 2018 6:33 pm

Any thoughts on getting a 2A or 4A 12V battery maintainer that auto-switches between supply input of 120V or 240V as needed, and splice it into the L1 and L2/N wires, as close as possible to the J1772 socket?

This would provide a charge or maintenance boost as needed to the 12V battery, any time the Leaf is actively charging via the L1 or L2 charger. This should keep the aux battery charged under normal conditions, although there still may be issues with extremely infrequent vehicle use.

The hardest part of the process would be making a clean splice into what is likely 8 (or maybe even 6) gauge stranded wires. The "intelligence" of the charging system is done through the other three connectors in the socket. The L1 wire is always 120V AC, the L2/N is either 120V AC, out of phase with L1, or neutral, depending on what is supplied to the EVSE, and both conductors are disconnected until the vehicle requests charge. And tieing in a device designed to use less than an amp to cables carring up to 30A is safe enough, as long as the connection is properly fused.

Or am I missing something?



grnbrg.

baustin
Posts: 655
Joined: Tue Feb 24, 2015 1:23 pm
Delivery Date: 09 Mar 2015
Leaf Number: 402162
Location: North Las Vegas, NV

Re: Solutions to 12 Volt Batteries and Chargers Posted Here

Fri Aug 17, 2018 4:07 am

The Leaf is already setup to charge the 12v battery whenever a charging session is initiated. If you need additional charging, get one of the low amp maintainers and the separate cable with connector that attaches to the battery. Run the end of the connector into the bay with the J1772 connector. Plug in the maintainer when you plug in the charging cable. Much easier and safer than what you propose.
2013 Leaf SV - Cayenne Red - QC Port - LED Headlights

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RegGuheert
Posts: 6319
Joined: Mon Mar 19, 2012 4:12 am
Delivery Date: 16 Mar 2012
Leaf Number: 5926
Location: Northern VA

Re: Solutions to 12 Volt Batteries and Chargers Posted Here

Fri Aug 17, 2018 5:26 am

baustin wrote:The Leaf is already setup to charge the 12v battery whenever a charging session is initiated.
Yeah, it charges the 12V battery for about 20 seconds (at least on the MY2014s and earlier). Then it goes into float mode at 13.1V for the rest of the charging session (except in low temperatures that you likely never see in Las Vegas).
baustin wrote:If you need additional charging, get one of the low amp maintainers and the separate cable with connector that attaches to the battery. Run the end of the connector into the bay with the J1772 connector. Plug in the maintainer when you plug in the charging cable. Much easier and safer than what you propose.
That won't work. The LEAF draws more current from the 12V bus during charging than "one of the low amp maintainers" is capable of putting out. As a result, the 12V battery will be floated at 13.1V just as it normally is.

If you want to use a low-amp maintainer to charge the 12V battery in the Nissan LEAF, use the maintainer when the LEAF's main battery is NOT charging.
RegGuheert
2011 Leaf SL Demo vehicle
10K mi. on 041413; 20K mi. (55.7Ah) on 080714; 30K mi. (52.0Ah) on 123015; 40K mi. (49.8Ah) on 020817; 50K mi. (47.2Ah) on 120717; 60K mi. (43.66Ah) on 091918.
Enphase Inverter Measured MTBF: M190, M215, M250, S280

arnis
Posts: 899
Joined: Sat Jan 23, 2016 3:21 pm
Delivery Date: 23 Jul 2014
Leaf Number: 015896
Location: Estonia, Europe

Re: Solutions to 12 Volt Batteries and Chargers Posted Here

Fri Aug 17, 2018 1:43 pm

RegGuheert wrote:Yeah, it charges the 12V battery for about 20 seconds (at least on the MY2014s and earlier). Then it goes into float mode at 13.1V for the rest of the charging session (except in low temperatures that you likely never see in Las Vegas)


Please, if you don't like efficiency mode, disconnect current sensor and
battery charging algorithm will stay in "non efficient always excessively charging 14.x V something mode" ;)
That is the only reason why Leaf has a current sensor. Add it to Arnis' DIY mod list :lol:

PS: Yesterday, I had one deeply discharged battery from another ICE. Battery was at 6V for a month. Connected it to Leaf's battery terminals. It took 2-3A for 10-30 minutes and then self-revived to healthy state. Took 50-60A for an hour. Then started to drop again. Leaf kept it at 14.4V for hours and then dropped back to maintenance level of 13.1V something after current dropped to few amps. Leaf's onboard DC-DC apparatus is ideal for lead acid battery charging, not on 2011-12 models as some say.
So disconnect current sensor plug.
Or, if you really want to see current data at LeafSpy, disconnect one of the pins and stick in a fixed resistor to trick charging system thinking battery is cold and needs more zap :)
Short range EVs <30kWh -- Medium range: 30-60kWh -- Long range: >60kWh
Charging: Trickle <3kW -- Normal 3-22kW -- Fast 50-100kW -- Supercharging >100kW

BrockWI
Posts: 652
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Delivery Date: 28 Mar 2014
Leaf Number: 423875
Location: Green Bay, WI.
Contact: Website

Re: Solutions to 12 Volt Batteries and Chargers Posted Here

Fri Aug 17, 2018 4:22 pm

Where is the current plug, anyone have a picture?
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2003 VW TDI 180k miles - 52 mpg lifetime
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arnis
Posts: 899
Joined: Sat Jan 23, 2016 3:21 pm
Delivery Date: 23 Jul 2014
Leaf Number: 015896
Location: Estonia, Europe

Re: Solutions to 12 Volt Batteries and Chargers Posted Here

Fri Aug 17, 2018 10:16 pm

This small thingy right at the negative 12V battery terminal.

Looks like this:
Image

Plug connection might look downward or away from battery, depending on the year AFAIK. Doesn't matter. Few thin wires go to that plug.
Short range EVs <30kWh -- Medium range: 30-60kWh -- Long range: >60kWh
Charging: Trickle <3kW -- Normal 3-22kW -- Fast 50-100kW -- Supercharging >100kW

BrockWI
Posts: 652
Joined: Fri Mar 28, 2014 6:28 am
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Leaf Number: 423875
Location: Green Bay, WI.
Contact: Website

Re: Solutions to 12 Volt Batteries and Chargers Posted Here

Sat Aug 18, 2018 6:36 am

That one, ok, I disconnected it on mine to see if this helps, I have had 3 dead 12v battery situations in the last two weeks. I believe something is staying on and drawing power, but this should at least help when it is "on" it charges the 12v more. While charging the traction battery the 12v was at 13.1 and disconnecting the shunt meter it went to 13.9v, I will watch it while driving and see where it is then.
3 kw solar pv - XW6048 - eight L16's
4 ton GSHP
2003 VW TDI 180k miles - 52 mpg lifetime
evse level 2 - Clipper Creek HSC-40
2013 S model with QC package Mar of 2013
@70k miles - 56.56Ahr - 86 SOH - 82.55 Hx - 245 GID

arnis
Posts: 899
Joined: Sat Jan 23, 2016 3:21 pm
Delivery Date: 23 Jul 2014
Leaf Number: 015896
Location: Estonia, Europe

Re: Solutions to 12 Volt Batteries and Chargers Posted Here

Sat Aug 18, 2018 9:12 am

Be sure not to leave any adapters in OBD port.
Also report back in a week or so. Higher voltage should help with
bad battery.
Short range EVs <30kWh -- Medium range: 30-60kWh -- Long range: >60kWh
Charging: Trickle <3kW -- Normal 3-22kW -- Fast 50-100kW -- Supercharging >100kW

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