Ok to charge 12V battery while still installed in LEAF?

I had an experience where the 12v discharged all the way. Normally on a gas car one would just hook up a charger. However, I notice on the leaf that there are many different types of cables hooked up to the 12v (all connecting to one lead), and I'm wondering if it's safe to just hook up a charger or should I disconnect the 12v to charge it? Probably a dumb question but I figured better safe than sorry! :roll:

bthatfield said:

I had an experience where the 12v discharged all the way. Normally on a gas car one would just hook up a charger. However, I notice on the leaf that there are many different types of cables hooked up to the 12v (all connecting to one lead), and I'm wondering if it's safe to just hook up a charger or should I disconnect the 12v to charge it? Probably a dumb question but I figured better safe than sorry! :roll:

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There's no problem charging it while connected.

I've done it. However, Ingineer advises that the negative cable should not be connected directly to the battery. He suggested clamping to the big cable that connects to the DC/DC converter, but any grounded place on the car away from the battery should work fine.

(The 2013 will look different under the hood but this is what it looks like on a 2012.)

Does the above advice still hold true given what the poster at http://www.mynissanleaf.com/viewtopic.php?p=388540#p388540 experienced?

I might be buying a used '13 Leaf SV soon and I have no idea what sort of condition the 12 volt is in. I do have a TecMate Optimate 4DUAL charger that I could use. I use it to charge and maintain the 12 volt on my 06 Prius.

I've connected the charger directly to my battery, with no apparent issues from doing so. It is safer to connect the positive cable first, and then connect the negative to a ground point away from the battery.

If you do get the 2013 Leaf, it will likely have the original battery. I would recommend popping off the caps and checking the fluid level in the cells. If they are low, top them off with distilled water. It will extend the life of the battery. Be careful not to get any dirt or debris in the cells.

cwerdna said:

Does the above advice still hold true given what the poster at http://www.mynissanleaf.com/viewtopic.php?p=388540#p388540 experienced?

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I think Ingineer's original recommendation to not charge direct to the battery posts is still correct.

When you charge direct to the posts, the LEAF negative lead current sensor is bypassed. That is undesireable for the LEAF knowing the 12V charge level.

When the other person hooked up charger and pulled a surge out of the 12V battery tripping their GFCI, the LEAF did the correct thing to charge the 12V back up.

But in any case it probably doesn't make a lot of difference, because the LEAF doesn't monitor the current all the time.
That is why it misses a lot of non-operating low level load on the 12V and tends to fail to keep it charged properly.
Particularly OBDII adapters pull quite a bit.

From my experience: (1) Hook up the remote de-energized ( unplugged) charger set at 2A trickle charge, positive or negative first, it doesn't matter, just make sure you have a GOOD connection direct to the 12V battery posts. THEN plug in your remote charger and check with a meter. The voltage will creep up from say 12.3 volts to 13.2V gradually and hopefully hold at that level after about 12 hours of charging at 2A setting.

^^^
Yes… my charger’s instructions (IIRC) basically to connect in this order: positive, negative (to the frame or unpainted bolt (I connect to a strut bolt on my Prius)), THEN connect the power.

And, for disconnecting, go in reverse order.

I’ve NEVER powered on my charger first then started connecting.

2 amps? IIRC, my Optimate 4DUAL doesn't go higher than 0.8 amps.

Is it ok to run my smart charger desulfate mode which outputs ~ 14.6 some-odd volts while the battery is hooked up to the leaf?

thx

vwDavid said:

Is it ok to run my smart charger desulfate mode which outputs ~ 14.6 some-odd volts while the battery is hooked up to the leaf?

thx

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Yes. 14.6V is ideal for charging the LEAF's 12V battery.

I've even gone as high as about 15.8V, which is what some desulfators on the market use. I don't recommend this, as desulfation can be accomplished in other ways without going above about 14.6V. At 15.8V, the battery will bubble a fair bit.

Above about 17V, you are risking damage to some of the equipment in the car.