Battery health during Coronavirus time

I have not driven my 2018 SL in 3 weeks due to the current situation.
When I was in the garage earlier I noticed one of the 3 blue charging lights was flashing. It went off after a few minutes.
I am pretty sure this means the 12V battery needed a charging and the traction battery was doing the work.
Is there anything we should do with our batteries to preserve good health to them since we will be driving less?

I saw the same thing the other day...yes...I think every ~24 hours or so, it charges the 12 volt battery if needed on the Gen 2 cars...like my 2019.

Keep the charge between 80%-20% would be my suggestion from the tons of reading I been doing

If you don't need 80%, then 50-60% would be better.

Baltneu said:

I have not driven my 2018 SL in 3 weeks due to the current situation.
When I was in the garage earlier I noticed one of the 3 blue charging lights was flashing. It went off after a few minutes.
I am pretty sure this means the 12V battery needed a charging and the traction battery was doing the work.
Is there anything we should do with our batteries to preserve good health to them since we will be driving less?

Click to expand...

General consensus seems to be a qualified "No" on the later models such as yours. Store the car longer term with roughly 50% charge on the traction battery. It should keep the 12v adequately, if not ideally charged by itself - the 12v charging algorithm seems to have been improved over the years to where many of us don't experience problems. Some have, however.

If you're looking for something to do, put the 12v on a "battery tender" - a small, smart charger that won't overcharge it. We've done that on both of our conventional vehicles, since we're not driving them, and they won't charge at all otherwise. Not too expensive, and useful. A "dumb" charger that just charges away without limits, however, will do more damage than good. Overcharging is just as bad as undercharging. Make sure your battery tender understands when to go into "float".

-b

Battery Tender Plus: I've used them for years. Easy to hard-wire to the 12V battery, and run the charging wire to come out in front with the other charging ports. I charge my 2015 every 2 months or so, and the AGM battery I've installed seems to be doing just fine.

The Battery Tender Jr. is a less expensive alternative. It only puts out 0.75A so it takes one forever to recharge a low 12 volt battery (although it will do it eventually) but it works fine as a maintainer. I've used them for years. One caveat, and it may apply to the bigger version as well: if you get an AGM battery, it may not work happily with it. I have three 100AH AGM batteries now, that I use for household power backup. Two of them stayed in bulk charge mode on the BT Jr, while the unit got hot and the batteries maybe got a bit overcharged. The third one works ok with the BTJ. Same brand and model batteries, too! This is a known issue with the Tenders.

Not going to do anything.
Appears that the battery algorithm will take care of things.
I will probably take it out once per week also

Baltneu said:

Not going to do anything.
Appears that the battery algorithm will take care of things.
I will probably take it out once per week also

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good idea...joy ride is needed sometimes

We are also not putting the Leaf on a battery tender. Only our conventional vehicles.

I've been worried about my Leaf, but haven't noticed any issues. We had decided that we would try to use my car more for short trips (local errands and such) since we can charge at home and keep my husband's ICE car reserved for longer trips to his job. However, we are pretty well stocked at home and he's just been stopping on his way home from work to pick up odds and ends so I haven't gone out. The only short distance trips we've been doing is to run across town to check in on family (usually drop offs of supplies). They don't need much so I haven't made that many trips. I think the longest gap was almost three weeks and I didn't notice any issues other than I need to replace the battery in my fob (it was due anyway).
I'm a little concerned about the long term impact this will have on the battery. I'm not sure what else to do besides keep it at most of a charge and try to drive it every once in a while. I guess it this somehow goes into the summer I'll worry about how I'm supposed to maintain it for the long-term then.

The consensus is that if you keep enough charge in the main battery, when the 12v battery needs a charge, the main battery will do its job. Enjoy your car.

I would personally keep my leaf SOC at 40% & absolutely use a high quality 12v maintenance charger if I was in your situation.

The leaf has very little if any meaningful parasitic drain on the main battery & 40% is a well known storage %. Think about the charge % when you buy a new cell phone & 1st turn it on.

I personally use a 1.5A "Smart Battery Charger" to periodically top off all of my 12V auto batteries.

A former co-worker whom was a Svc writer at a dealership for 2 decades had told me that a battery company rep advised him to do that monthly & his batteries would last 2-3x longer due to the sulfating that occurs over time on the lead acid plates when not at a full charge which ironically is opposite of best practice for all type of lithium ion.

My anecdotal evidence is that my build date of January 2013 Prius with 140K miles still has its original OEM 12V battery which is a known common & early failure part for that car & is still working just fine for me.

Bottom line: EVs survive "storage" situations better than any ICE ever did/would.
Follow the charge guidelines mentioned in this thread...don't leave it sitting around "full"...and don't worry about how much you do/don't drive it any given week. Current (intermittent) driving habits are what EVs were built for!

Baltneu said:

The consensus is that if you keep enough charge in the main battery, when the 12v battery needs a charge, the main battery will do its job. Enjoy your car.

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If there is any "consensus" at all, it is that the Leaf should charge the 12 volt battery periodically, but that it may not, in some circumstances, do a great job of it. My 2018 has been measured by me at about 12.3 volts, which is too damned low.

Why is 12.3 volts too low? It is a 12v battery.

Baltneu said:

Why is 12.3 volts too low? It is a 12v battery.

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Somewhere in the distant past, a big mistake was made: so-called "nominal" voltage was used to categorize the group of batteries now known as "12 volt." In fact, 12.0 volts is very nearly dead, and 12.3 volts is something like 45% charged. a "full" 12 volt battery will read just under 13.0 volts, and a "12 volt" AGM battery will read about 13.35 volts when fully charged.

I followed a Leaf FB discussion, one local left his 40kWh 100% charged for 6 weeks, when he booted it up and drove it SOH dropped by over 2%. It might bounce back, but still it felt bad for him.

It seems to be more important for 40/62kWh Leafs to make sure SOC is in the middle since these batteries charge to 4.20V/cell.

The older 24/30kWh packs only go to 4.13V, so "100%" SOC on these are not as bad.

Dala said:

I followed a Leaf FB discussion, one local left his 40kWh 100% charged for 6 weeks, when he booted it up and drove it SOH dropped by over 2%. It might bounce back, but still it felt bad for him.

It seems to be more important for 40/62kWh Leafs to make sure SOC is in the middle since these batteries charge to 4.20V/cell.

The older 24/30kWh packs only go to 4.13V, so "100%" SOC on these are not as bad.

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Wow that's unfortunate for that owner. No Lithium Ion battery should EVER be stored or left unused at 100% SOC. Ideally keep them around 40%. I only charge my handheld power tool packs to 50% until I need to use them for the same reason & get years & years of service out them.

I have multiple clients with Teslas & I have convinced them to set their daily charge to 65% to enable them much longer pack lifespans because 65% of a 75kwH pack is still over 200 miles & for local driving is TONS of range

Thanks. I was off on my memory of SOC equivalents, but 12.3V/70% is still well below good storage voltage for a "12 volt" battery.