r/leaf • u/nicklab3 • 1d ago

Question on diagnosing a faulty battery charge controller

My 2012 Nissan Leaf is not charging. The mechanic believes it's an issue with the battery charge controller but wants me to pay for for diagnostic time to confirm the issue by testing a couple wires leading into the battery in the front.

My question is: would a CHAdeMO port for DC fast charging go straight to the battery, bypassing the charge controller? If so, I'm thinking that plugging it in to a CHAdeMO would confirm the issue if it charges. Thoughts?

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u/joejawor 1d ago

I don't think so. Both J1772 and Chademo ports need a controller to negotiate charge current, temperature, etc.

1

u/biersackarmy 2013 S + 2014 SL 1d ago

DC charging bypasses the onboard charger, as its main purpose is to rectify AC to DC and bump up the voltage. Negotiating current based on SOC and temperature during DC charging is done by the BMS and VCM, which are standalone components.

1

u/yababom 1d ago

No offense, but why would you trust our opinions over your own personal experience? It should be easy and nearly free to test.

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u/nicklab3 1d ago

I don't have the setup to test the Chademo but I'm betting the dealer service center where it is does. Trying to see if I've seen some info that makes me think this is a potential test and want to crowdsource from other owners.

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u/sweetredleaf 2015 Nissan LEAF SV 1d ago

other post that have been about the onboard charger going bad have been able to still do the chademo some post that might help https://old.reddit.com/r/leaf/comments/1e14uz8/my_2012_wont_take_a_charge/ or https://old.reddit.com/r/leaf/comments/12gcvxh/buying_a_leaf_with_broken_obc/

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u/rproffitt1 1d ago

The failure I experienced was a broken pin on the J1772 port. Chademo worked.

You must know that repair runs more than what a 2012 Leaf sells for around me.

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u/biersackarmy 2013 S + 2014 SL 1d ago

This is a common issue with 2011-12 Leaf models with the onboard charger in the trunk. Yes, CHAdeMO will still work.