Silverfish
Posts: 28
Joined: Thu Jun 21, 2018 10:32 am
Delivery Date: 21 Jun 2018

Re: Charge a little each day, or longer charges every few days?

Fri Jun 22, 2018 1:44 pm

davewill wrote:
powersurge wrote:I wouldn't charge to 80% in your case since the car would be at this level permanently.

The battery lasts the longest if you leave it constantly at 50%. So I would leave it at 40%-60%, and you have at least 20 miles of solid range at any time.

then charge the car with a timer back to 60% (unless you want to go farther). On those days, charge the car up to 100% and go,....

And if a situation comes up where you want to go more than 20 miles away, but you didn't know that the night before? Keeping the battery that low is a ridiculous waste of effort for a very questionable return.


I should have mentioned that we have a gas car too, so we can just switch vehicles if longer distances are called for. Otherwise, yeah, I'd keep the Leaf charged up all the time.

Leaf15
Posts: 46
Joined: Sat Jun 09, 2018 6:51 am
Delivery Date: 09 Jun 2018

Re: Charge a little each day, or longer charges every few days?

Sun Jul 01, 2018 6:44 am

I commute to work average 20 miles a day, so I charge every 2-3 days depending on errands. Very rare I do it next day, because of too many miles driven. I think it is beneficial to get battery to low state once a month - it allows low charge state balance of cells and I usually charge L2 to 100% during night hours (with timer) when temperature is low. We know Nissan only charges to 90% of the real capacity. Also, we know that charging last 10% to reach real full capacity would take way too long, possibly the main reason why all EV manufacturers to limit it to 90% of real capacity. But when you fully charge it - it allows cells to balance in high charge state. Partial charge will not allow this to happened as battery do not reach saturation point. The Leaf battery is relatively small so loss of regen effectiveness during a few first miles on full battery is not a big of a deal.
Leaf 2015 SV CPO

Silverfish
Posts: 28
Joined: Thu Jun 21, 2018 10:32 am
Delivery Date: 21 Jun 2018

Re: Charge a little each day, or longer charges every few days?

Sun Jul 01, 2018 10:08 am

Leaf15 wrote:I commute to work average 20 miles a day, so I charge every 2-3 days depending on errands. Very rare I do it next day, because of too many miles driven. I think it is beneficial to get battery to low state once a month - it allows low charge state balance of cells and I usually charge L2 to 100% during night hours (with timer) when temperature is low. We know Nissan only charges to 90% of the real capacity. Also, we know that charging last 10% to reach real full capacity would take way too long, possibly the main reason why all EV manufacturers to limit it to 90% of real capacity. But when you fully charge it - it allows cells to balance in high charge state. Partial charge will not allow this to happened as battery do not reach saturation point. The Leaf battery is relatively small so loss of regen effectiveness during a few first miles on full battery is not a big of a deal.


When you say get the battery to a low state, do you mean to 30%, at the Low Battery Warning? Or do you mean even lower than that?

Thanks.

Leaf15
Posts: 46
Joined: Sat Jun 09, 2018 6:51 am
Delivery Date: 09 Jun 2018

Re: Charge a little each day, or longer charges every few days?

Sun Jul 01, 2018 7:10 pm

Silverfish wrote:
When you say get the battery to a low state, do you mean to 30%, at the Low Battery Warning? Or do you mean even lower than that?

Thanks.

I meant Low Battery warning that kicks in at 15 miles of range left. I usually drive a few miles at this point to get home. I never got below that (like in turtle mode) , it would be too daring. Interesting observation, I usually disable Eco mode at low battery and drive it like I stole it for a few miles, because of I know I could get home just in time. Try to go accelerate uphill in Eco mode and then half way turn off Eco mode. It would create an effect like somebody drops a sledge hammer. There is no way you can modulate this quickly with accelerator, the Eco On/Off is instant. This help to remind me this car is no slug at all. So when you get home with less than 15 miles left, let it sit for a while - this will allow cells to rebalance in low state. I plug the L2 charger, but charging (timer #1 configured this way) starts at 1:00AM and stops at 6:00AM. Someone also mentioned after this low to 100% charge cycle, let it sit for a few hours and then re-connect charger to top it off to complete the cell balancing.

There was a discussion how to keep battery healthy for a long time and there was one post about how one owner keeps battery in good shape for long time and this was suggested. Unfortunately, I could not find this post, but just remember the procedure. Anyway, being a mechanical engineer, I found it very reasonable suggestion. This is not every charge cycle, it was suggested to do it once every 2-3 month. I would do it when opportunity presents itself, so 2-3 month is plenty time to catch those moments.
Leaf 2015 SV CPO

be236
Posts: 79
Joined: Sun Jul 15, 2018 9:13 pm
Delivery Date: 07 Jul 2018
Leaf Number: 309258
Location: Seattle, WA

Re: Charge a little each day, or longer charges every few days?

Sat Jul 21, 2018 3:00 pm

So, I'm still don't not clear on the consensus for the original question...

Basically, if I only drive a few miles each week, should I L2 charge it even when I'm at 60-80% to charge it to 95% if the opportunity is there in short sittings...

... or should I wait until the battery goes down low to like 10-20% and charge it up to 95% in one long sitting?

Or does it not matter?
Nissan LEAF 2017 S.

manidhan
Posts: 14
Joined: Thu Jan 01, 2015 1:08 pm
Delivery Date: 01 Nov 2014
Location: Sunnyvale, CA

Re: Charge a little each day, or longer charges every few days?

Sun Jul 22, 2018 1:54 pm

be236 wrote:So, I'm still don't not clear on the consensus for the original question...

Basically, if I only drive a few miles each week, should I L2 charge it even when I'm at 60-80% to charge it to 95% if the opportunity is there in short sittings...

... or should I wait until the battery goes down low to like 10-20% and charge it up to 95% in one long sitting?

Or does it not matter?


It depends on the area where you live (or the average temperature). Dave here has a bog on EVs and the following post shows what state of charge is best for leaving it long (overnight or more)

http://daveinolywa.blogspot.com/2017/10/

The chart in the blog shows ideal SoC for every temperature. Based on your location (and season), you can find what is right for you. Hope this helps.

LeftieBiker
Posts: 9568
Joined: Wed May 22, 2013 3:17 am
Delivery Date: 31 May 2013
Location: Upstate New York, US

Re: Charge a little each day, or longer charges every few days?

Sun Jul 22, 2018 2:01 pm

I'm not sure how Dave arrived at the chart, but take it with a grain of salt. Generally, roughly a 50% charge is a good compromise between range and longevity for EVERY temperature.
Scarlet Ember 2018 Leaf SL W/ Pro Pilot
2009 Vectrix VX-1 W/18 Leaf modules, & 3 EZIP E-bicycles.
PLEASE don't PM me with Leaf questions. Just post in the topic that seems most appropriate.

Silverfish
Posts: 28
Joined: Thu Jun 21, 2018 10:32 am
Delivery Date: 21 Jun 2018

Re: Charge a little each day, or longer charges every few days?

Sun Jul 22, 2018 3:47 pm

Part of what's so confusing about all this is that so many people declare, with such conviction, such contradictory things, in various forum threads and websites:

"Stay around 50%. No, drain the battery down to 20-30% and then charge to 80%. Charge to 100%. Charge to 80%. It doesn't really matter if you charge to 100%. It does really matter if you charge to 100%. Charge to 100%, but make sure you jump in the car immediately and start driving. Charge to 100%, and it's fine to leave it that way for a day or two. Here's a chart. Here's a different chart. Quick charge is bad for the battery. Quick charge is fine, I do it all the time, and I haven't dropped a battery bar yet. Just drive the way you want to drive, and don't get too hung up on the details. Get hung up on the details or your battery will degrade quickly, and since they now cost $8500 to replace, you're hosed."

I don't mean to sound ungrateful; I genuinely appreciate all the advice I've gotten here, and all the posts I've read. It's just hard to know what to make of all the advice when you're a noob. Personally, I've observed that my battery SOH seems to improve when I drive longer distances at a time, counterintuitive as that seems, and also when I do a deeper discharge and then recharge, like from 30% to 80% instead of 40% to 60% -- but this is from LeafSpy, and apparently the SOH readings tend not to be reliable over short periods of time, so that observation may be totally wrong. And I've only had my car for a couple of months (2013 SV, 11 bars but dropping to 10 any minute now, non-lizard battery).

I have no idea how everyone came to their recommendations. It's possible that no one really knows for sure, and since people's experiences are different, their advice is different. The only things people seem to mostly agree on are:

1. L1 and L2 charging keeps the battery cooler, which is good. Quick charge (L3) only when necessary.
2. Heat isn't great for the battery.
3. Driving faster drains the battery faster.
4. Drive gently to extend range.

Right now, what I'm doing is charging to 80%, driving for a few days until I hit the low battery warning (at a little over 30%), and then recharging to 80%, typically at night when temps are at their coolest. I'm collecting data as I do that, mostly about miles driven and SOC, which seem to be the most solid numbers. I may then try the same thing charging to 100%, and compare data.

I did try charging a bit each day and keeping the battery between 40% and 60%, but the SOH did not seem to like that -- which, again, might be meaningless over such a short period of time.

LeftieBiker
Posts: 9568
Joined: Wed May 22, 2013 3:17 am
Delivery Date: 31 May 2013
Location: Upstate New York, US

Re: Charge a little each day, or longer charges every few days?

Sun Jul 22, 2018 4:39 pm

Right now, what I'm doing is charging to 80%, driving for a few days until I hit the low battery warning (at a little over 30%), and then recharging to 80%, typically at night when temps are at their coolest. I'm collecting data as I do that, mostly about miles driven and SOC, which seem to be the most solid numbers. I may then try the same thing charging to 100%, and compare data.


This is a good strategy. However, you shouldn't be getting any kind of "low battery warning" at 30%, unless you have a severely degraded battery. More like 18-20%.

As for the motivations behind what you see posted here: some people want you to do as they do, or at least to stop worrying completely about the battery, so they tell you to charge it to 100% and drive it any way you want. Others look at lithium battery lab tests and want you to do what is best for a battery sitting on a test bench, with no concern for range, or temperatures. As for me, I've been reading what people do in the real world, done some real world testing myself, and I try to suggest what works reasonably well without requiring any extreme measures. (If I do suggest extreme measures, like for cars in Hot climates, I make it clear that it shouldn't be like this in 2018, and shame on Nissan.)
Scarlet Ember 2018 Leaf SL W/ Pro Pilot
2009 Vectrix VX-1 W/18 Leaf modules, & 3 EZIP E-bicycles.
PLEASE don't PM me with Leaf questions. Just post in the topic that seems most appropriate.

Silverfish
Posts: 28
Joined: Thu Jun 21, 2018 10:32 am
Delivery Date: 21 Jun 2018

Re: Charge a little each day, or longer charges every few days?

Sun Jul 22, 2018 7:37 pm

LeftieBiker wrote: This is a good strategy. However, you shouldn't be getting any kind of "low battery warning" at 30%, unless you have a severely degraded battery. More like 18-20%.


In the two months I've had the car, I always get a low battery warning at 16-17 miles on the guess-o-meter, which registers as between 29% and 32% in LeafSpy. I did wonder about that.

How would I know if I had a severely degraded battery? The range is pretty consistent at about 70-75 miles on the GoM at 100% charge, and 55-60 miles at 80% charge, depending on how much freeway driving I've been doing. On 100% charge, I can generally drive 50-55 miles before hitting the low battery warning. On an 80% charge, it's about 30-35.

It's a 2013 SV with about 53,700 miles and 11 bars. SOH is hovering between 76% and 77%, so I'm surprised it's not yet at 10 bars. Do all those numbers not add up right? Maybe there's a way to reset the % at which the LBW sounds, and the previous owner did? I'd be happy to drive it down to 20%, just been nervous because of the warning.

Thanks.

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