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Re: How fast does the 12 volt battery charger charge?

Posted: Thu May 09, 2013 8:11 am
by EVDRIVER
electrifeyed wrote:Here's a question: could you replace the original 12-v battery in Leaf with a larger deep-cycle one (assuming you could make it fit in the space)? (Or would this do more harm than good, since car recharges this from the traction battery?


There is really no reason to do this. If you don't abuse your battery there should be no issues.

Re: How fast does the 12 volt battery charger charge?

Posted: Thu May 09, 2013 8:28 am
by Stanton
electrifeyed wrote:Here's a question: could you replace the original 12-v battery in Leaf with a larger deep-cycle one (assuming you could make it fit in the space)? (Or would this do more harm than good, since car recharges this from the traction battery?


If you're looking for more "run time" on your hi-fi (or accessories), consider replacing the 12v lead-acid with a 12v Lithium; I've been very happy with mine. Search for my thread or read my MNL blog entry ("Get the Lead Out").

Re: How fast does the 12 volt battery charger charge?

Posted: Thu May 09, 2013 9:03 am
by Nubo
EVDRIVER wrote:
electrifeyed wrote:Here's a question: could you replace the original 12-v battery in Leaf with a larger deep-cycle one (assuming you could make it fit in the space)? (Or would this do more harm than good, since car recharges this from the traction battery?


There is really no reason to do this. If you don't abuse your battery there should be no issues.


From the point of view of a lead-acid battery, this car abuses the 12V battery as a matter of course. My OEM was on the way out after a year's duty. I wouldn't consider my habits abusive, although I commonly leave the car plugged into the EVSE on days where I don't drive it. This increases the dark-current load on the 12V battery and, perversely, inhibits the car from charging it. Thus the LEAF's battery experiences deep cycling by its design.

I replaced the 12V with an AGM deep-cycle, which is so far holding up quite well. viewtopic.php?f=27&t=11094&p=257210

Re: How fast does the 12 volt battery charger charge?

Posted: Wed Jul 06, 2016 7:56 am
by mr23
Ingineer wrote:WARNING: NEVER connect anything directly to the negative post of the Leaf's 12v aux battery! This is a current sensor and doing so will disrupt the charging system! (Connect all accessories to the body ground, or, if high-current, the black wire screwed to the top of the DC-DC JB. (Behind the inverter)

-Phil


I just looked my Leaf over, and while I agree you shouldn't connect anything directly to the negative post, clamp or screw, it is fine to connect to the post/nut where the chassis negative cable connects. The current sensor is in between that point and the battery post clamp.

Re: How fast does the 12 volt battery charger charge?

Posted: Wed Jul 06, 2016 9:22 am
by TimLee
^^^ Correct.
As clearly stated by Phil in the jump starting instructions.
See viewtopic.php?f=9&t=6707&hilit=jump+start&start=10#p148133.

Re: How fast does the 12 volt battery charger charge?

Posted: Wed Jul 06, 2016 2:11 pm
by LeftieBiker
I don't think that anyone answered the critically important question of whether or not the car charges the 12 volt battery while off, because of the possibility of adding large drain accessories. The car does charge the battery every few days, but not enough for any additional loads! In fact, it often isn't enough for expected loads, like having the charging cable connected while the car isn't charging. I short, don't add any car-off loads.

Re: How fast does the 12 volt battery charger charge?

Posted: Wed Jul 06, 2016 4:11 pm
by knightmb
LeftieBiker wrote:I don't think that anyone answered the critically important question of whether or not the car charges the 12 volt battery while off, because of the possibility of adding large drain accessories. The car does charge the battery every few days, but not enough for any additional loads! In fact, it often isn't enough for expected loads, like having the charging cable connected while the car isn't charging. I short, don't add any car-off loads.

If the vehicle is in ACC mode (just the radio works) then it will run the 12 volt battery to shutdown, no recharge, you'll need a jump to get the vehicle working again. If the vehicle is off, you can run the battery down also, no charging will activate.

If the vehicle is in Standby mode (dash active, radio active, but not drive-able), it will activate the 12 volt system when the battery gets down to 10.5 volts to charge it back up. This is the mode I use to power up my house for emergency power (so the vehicle can't be driven off by accident). But I keep the charge mode active non-stop by keeping a load of at-least 50 watts going so that the battery never tops off and it stops charging.

Finally, if the vehicle is in drive mode, the 12 volt system is active all the time until you drain the traction battery to shutdown.

Re: How fast does the 12 volt battery charger charge?

Posted: Wed Jul 06, 2016 4:53 pm
by jjeff
knightmb wrote:
LeftieBiker wrote:
If the vehicle is in Standby mode (dash active, radio active, but not drive-able), it will activate the 12 volt system when the battery gets down to 10.5 volts to charge it back up. This is the mode I use to power up my house for emergency power (so the vehicle can't be driven off by accident). But I keep the charge mode active non-stop by keeping a load of at-least 50 watts going so that the battery never tops off and it stops charging.

I take it your powering a 120v inverter off the 12v Leaf battery and what is it's wattage? On a link somewhere at MNL I saw where it was possible(or maybe a future thought) to power a mains outlet directly from the traction battery. The vehicle in question was a eNV200 and was meant to provide mains power to construction job sites where a noisy smelly generator wasn't wanted.
Personally thats the type of power I'd want, something I could run my house off of for a limited amount of time during a several hour power outage. Of course not the central air or things like a stove or dryer but things like the TV, lights, refrigerator/freezer and maybe water pump for those with a well. Maybe someday it will be reality......

Re: How fast does the 12 volt battery charger charge?

Posted: Wed Jul 06, 2016 4:55 pm
by TimLee
The LEAF has a wonderful DC to DC for charging the 12V.
But the software for its use does a poor job of keeping it anywhere near fully charged.

Using high power demand devices will make things worse.

At least in drive it will hold the 12V near 13V.
But you will need to frquently put a battery tender on it if you expect it to hold up long term.

Re: How fast does the 12 volt battery charger charge?

Posted: Wed Jul 06, 2016 7:45 pm
by Marktm
jjeff wrote:Personally thats the type of power I'd want, something I could run my house off of for a limited amount of time during a several hour power outage. Of course not the central air or things like a stove or dryer but things like the TV, lights, refrigerator/freezer and maybe water pump for those with a well. Maybe someday it will be reality......


It's been done by many with the Prius traction battery - up to 4-5 kw peak. Two major differences;
1. The Prius will recharge the (smallish) traction battery indefinitely as long as the tank has gasoline
2 . The Prius traction battery voltage is ~ 200 VDC - there are a number of commercial quality inverters that operate in that range and that have commercial quality transformers to produce the needed 240 VAC split phase.

I am not able to find any such equivalent inverter/transformer combinations that match the ~ 400 VDC requirement. There is an 8 kw inverter that operates at 400 VDC, but requires a center (battery) tap at 0 VDC (+/-200 VDC) that appears to direct connect to the 240 VAC "neutral" output - which likely disqualifies it for any use except a self-contained battery system - not being an EE, I'm not sure. I'll bet that soon there will be a V2H system that has such an inverter designed for 240 VAC split phase - can I justify it? Probably not.