Posts: 78
Joined: Mon Oct 30, 2017 6:45 pm
Delivery Date: 07 Oct 2017
Leaf Number: 305601

Solution to 12V SLA Battery Going DEAD? Direct Charge Cable.

Thu Oct 29, 2020 1:09 pm


My 12V battery decided to drain itself again for some reason. :oops: It has happen at random a handful of times over 3 years. Yes I have the 3-g telematic update. It's very annoying. Fortuitously it has always been at home and never caused me an issue. LEAF is a 2nd Car....

Solution: I connected direct to battery (with a 5 amp inline fuse) and routed it to the nose hatch to charge the battery w/o popping the hood. There is a gap in the corner. So wire routing is easy. The connector is a FLAT 2 POLL connector similar to utility trailer. It connects to an extension, to a trickle charger. I measured current when charging. It drew about 1/2 Amp when charging a partially drained (60%) battery. Obvious advantage is not having to pop hood and clip onto battery. I hope this does not cause an issue if charging the battery while charging the drive battery pack.

Solution: Also I monitor the battery voltage. I NOW[ have a battery monitor in the Lighter Socket. I can keep an eye on it when driving. No surprise battery is always under charged or in low charge state. Typical volts I see driving around is 12.8 to 13.1 volts, basically nominal charge of battery. In ICE cars their electrical system typically is at 13.8 to 14.5 volts.
  • If it works (I use it) I will put a hard mounted receptacle so I don't have to use two hands to plug in and unplug.
  • I may move the connector to the lower side grill so I can plug battery charger in without opening the nose charge door.
Last edited by gmcjetpilot on Thu Oct 29, 2020 2:55 pm, edited 2 times in total.

Posts: 15806
Joined: Wed May 22, 2013 3:17 am
Delivery Date: 30 Apr 2018
Location: Upstate New York, US

Re: Solution to 12V SLA Battery Going DEAD? Direct Charge Cable.

Thu Oct 29, 2020 1:35 pm

The connector is probably an SAE connector, and lots of us have done this. I drilled a hole in the charge port compartment and then plugged it when I turned the car in. This time I plan to drill a hole, use a rubber grommet, and keep a rubber plug handy if we turn the 2020 Leaf in. There is no harm in charging the auxiliary battery along with the main pack.
Scarlet Ember 2018 Leaf SL W/ Pro Pilot
2009 Vectrix VX-1 W/18 Leaf modules, & 3 EZIP E-bicycles.
PLEASE don't PM me with Leaf questions. Just post in the topic that seems most appropriate.

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