Charging Questions re SPARK battery

[EVlearner]

Hi all,
I am a cousin EV owner here, of a FIT EV actually, and hope you may be able to provide me with some info.

I read on that the Toyota RAV 4EV and the Nissan Leaf are supposed to be charged ONLY up to 80% as normal charge, and up to 100% as extended charge (and only if you use it right away and do so on rare occasions). I also read that one should not charge a "hot" battery, presumably, a car that has been driven for X miles. Didn't say how long to wait before charging but I would guess at least 15 minutes. This is to lessen battery degradation.

The FIT EV manual says nothing about these two items. (Granted, the FIT EV is a test car so maybe Honda doesn't want to tell us what to do just to see what happens to the batteries over time).

Can you tell me if the SPARK EV has any direction in the manual when it comes to charging on these issues?

I think all of our cars use this lithium based battery so I assume the degradation factors may be similar? I'm going to also see if our Ford Focus cousins or Fiat 500e's have any info in their manuals.

Thanks in advance for any info, happy EV driving!

 

[TonyWilliams]

The LEAF is the ONLY car that somebody would suggest to wait to cool for charging. All the other EVs on the market have some sort of battery cooling that will operate while driving or charging, and in some cases when doing neither driving, nor charging (just parked).

The 100% charge guideline isn't for "rare" occasions... you can charge to 100% every time you charge, if you want. Just don't leave the battery parked that way. Charge it and drive it. No month long vacations with the car fully charged and parked.

If you going on a trip and leaving you lithium battery EV, I recommend leaving the battery at 50% and in a cool spot while parked.

The Spark EV uses nano lithium iron phosphate (LiFEO4) chemistry

Honda Fit EV uses Toshiba-made SCiB (super-charge ion battery), which employ a Lithium Titanate Oxide (LTO) anode

LEAF and Volt use Lithium Manganese Oxide (LMO) cells, however the Volt battery is from LG Chem, and the Leaf battery cells are from AESC, a joint venture between NEC and Nissan.

 

[EVlearner]

Hi
I really appreciate how knowledgeable you are.. Thank you again.. I find lots of useful discussion on the Toyota forum and enjoy reading your and others posts there. Anyway, I keep seeing the rav 4ev'ers distinguishing between charge to normal range vs extended range, so I got worried because I do charge to 100% (but use it right away). Ok I feel better now. I also found the online manual for focus electric and 500e, and you are right, they say nothing about the 80% or hot battery. And Spark too.
It occurs to me now that if I did have a rav4ev, I prob wouldn't need to charge to extended range all the time because my commute is 80 roundtrip.

 

[fengshui]

The spark EV manual recommends charging fully every time, and leaving the vehicle plugged in when not in use:

Plug-In Charging
This section explains the process
for charging the high voltage battery.
Do not allow the vehicle to remain in
temperature extremes for long
periods without being driven or
plugged in. It is recommended that
the vehicle be plugged in when
temperatures are below 0°C (32°F)
and above 32°C (90°F) to maximize
high voltage battery life.

In order to maintain maximum range
from the battery, fully charge the
battery at each charge event. It is
not recommended to partially
charge the battery.

http://www.chevrolet.com/content/dam/Chevrolet/northamerica/usa/nscwebsite/en/Home/Ownership/Manuals%20and%20Videos/02_pdf/2k14spark_ev.pdf

 

[gra]

IIRR, the LTO (anode) in the Honda Fit gives it a wider usable SoC range than either the graphite-LMO in the LEAF or the graphite?-LFP in the Spark. It also has good cycle and calendar life, and good high temperature tolerance. The downside is its low energy density (about half that of a graphite anode) and high voltage (it's the difference in voltage between the anode and cathode that determines potential) which further limits its energy density. A typical graphite anode has a voltage in the 0.0-0.1V range, while a Ti anode runs 1.0-2.0 volts. It's a case of TANSTAAFL - while the longest-lived and probably safest battery would be a LTO-LFP combo, they'd also have the worst energy density.

In general, don't try to apply the rules for one Li-ion chemistry straight across to another. Go by what the Fit's owner's manual says, but as Tony mentions its better not to leave the car at a high SoC for a long time, as that's inherent to all the Li-Ion chemistries. Of course, some manufacturers may be limiting their batteries to a lower max. voltage and SoC range than others, to protect them. Chevy does this with the Volt but I don't know if they do so with the Spark's different battery chemistry, nor do I know what Honda is doing with the Fit.

 

[EVlearner]

thanks fengshui and gra!

Interesting about charging battery until full for SPARK... that's what I thought I had to do with the FIT EV too just because it seemed logical but it was problematic when I couldn't always wait (and then I read about the 80% rule for LEAF and started worrying I was overcharging! :? )

Gra - wow, I am in awe of how much you know and what you wrote! These batteries, electricity, so complicated! Thank you for simplifying, it makes sense to me now that batteries not all the same even if lithium-based, because of all the other variables.

The FIT EV manual doesn't say much about charging, I think it does say what Tony recommends which is to not leave it at full battery if car isn't used for a while. Honda probably doesn't tell us lessees much by design so they could gather lots of varied data... I guess they may really be crushing these cars when they get them back

Thanks again! Happy Labor Day!

 

[drivefast]

common sense tells me that if the batteries were not safe to repeatedly charge to 100%, the default charging were set for 80% or whatever, and you would have to manually push it for 100% when needed. that, and the computer would probably had a counter of how many times you can fully charge to 100%, so that the manufacturer can blame it on you if you do it too often. (dont know much about chemistry, but i'm comfortable with how computers work )

 

[TonyWilliams]

... the computer would probably had a counter of how many times you can fully charge to 100%, so that the manufacturer can blame it on you if you do it too often. (dont know much about chemistry, but i'm comfortable with how computers work )

The Nissan LEAF has a counter for every DC quick charge and every L2 charge. I don't think it tracks how much time at a specified SOC%.

Don't worry, they will blame you anyway!!!

 

[TonyWilliams]

In order to maintain maximum range
from the battery, fully charge the
battery at each charge event. It is
not recommended to partially
charge the battery.

That's a little nutty. They seem to be saying to not partially charge for maximum RANGE. For maximum life of the battery, leave it closer to 50% SOC, and cool.

 

[fengshui]

That's a little nutty. They seem to be saying to not partially charge for maximum RANGE. For maximum life of the battery, leave it closer to 50% SOC, and cool.

They may be figuring that with a A123 battery, they're better off having AC power available for the TMS to do its job over being disconnected and having to use the battery power for TMS.

 

[TonyWilliams]

That's a little nutty. They seem to be saying to not partially charge for maximum RANGE. For maximum life of the battery, leave it closer to 50% SOC, and cool.

They may be figuring that with a A123 battery, they're better off having AC power available for the TMS to do its job over being disconnected and having to use the battery power for TMS.

Could be? I really have no idea what the parameters are for TMS on the Spark EV.