L3 Charger...is it worth the $700?

[garygid]

You may be correct about a too-old system.

However, an "inexpensive" HomeLink-compatible receiver can be purchased and easily wired to "push" your inside opener button (actually, wired in parallel with the button, to just "short" the wires together).

 

[AndyH]

Battery-Cell Management - a difficult task:

<snips>

The Quick-Charge ("L3") apparently stops without spending time trying to "balance", so the more conservate 80%-charge figure is given. In fact, with a well-balanced battery pack, there is no good reason that a Rapid-Charge could not get a 90%, or even 95% charge.

Maybe, Gary. It sounds like you're describing 'top balancing' where the system must completely fill each cell to the designated 'max'. There are other methods available for balancing - some of these made easier by the more lead-acid-like slope of the LiMn charge/discharge curve over the relatively flat curve of LiFePO4 or LiPo. If the car is monitoring the capacity of each parallel group, for example, it can shuttle energy around so the pack's balanced at, say, 60%. We have no indication that Nissan's actually doing that, though - just like we really don't know if they're top balancing.

What's more likely - and what's already been done with earlier cars - is that the system will keep voltages in check day to day while allowing everything else to shift a bit with time. When the pack and car's computer get out of sync, the car will likely call for service (throw an error code) and we'll (er, I mean the dealer tech...) will follow the discharge/recharge re-sync process in the shop. This is required now for things like laptop computer packs and earlier EVs like the Ranger and S10. Here's an example procedure.

I don't agree with your assessment of a 90 or 95% quick charge - even if only talking 90-95% of the smaller 'user' charge range - solely because of heat.

Pack balancing is not something that's going to be left to us users - we don't have to think about it or worry about it. We don't even have access to the top or bottom range of the pack - so top- or bottom-balancing isn't even something we can do! Best we can do is label it "FM" (freakin' magic) and move on.

 

[hill]

. . . . . . . . . . . . . snip
Funny about the automatic headlights leaffan! Its not like the SV won't have any headlights at all! Right now, whether day or night, I switch on the headlights when I start the car and switch them off when I shut it off.As a safety issue, I appreciate day-running lights.
. . . . . . . . . . . . . . . . . . snip

Had the statement been, "As a perceived safety issue, ..." I would have let it go. Studies have shown that perception and reality do not always converge.

http://blog.motorists.org/daytime-running-lights-no-statistically-significant-effect-on-safety/
"...DRLS not only did not improve highway safety, rather they detracted from highway safety ..."

Choosing to spare mynissanleaf readers an exhaustive list, the above link simply typifies dozens of articles. Marketing can sell SUV's as "Sexy" ... and DRL's can be sold as "safe". The reality is that profit is the reason for both. A behemoth yields more profit, and extra goodies (like DRL's) yield more profit.

.

 

[evnow]

I think the real safety device in SL is the rearview camera. I'm getting SL mainly for that.

 

[AndyH]

. . . . . . . . . . . . . snip
Funny about the automatic headlights leaffan! Its not like the SV won't have any headlights at all! Right now, whether day or night, I switch on the headlights when I start the car and switch them off when I shut it off.As a safety issue, I appreciate day-running lights.
. . . . . . . . . . . . . . . . . . snip

Had the statement been, "As a perceived safety issue, ..." I would have let it go. Studies have shown that perception and reality do not always converge.

http://blog.motorists.org/daytime-running-lights-no-statistically-significant-effect-on-safety/
"...DRLS not only did not improve highway safety, rather they detracted from highway safety ..."

Choosing to spare mynissanleaf readers an exhaustive list, the above link simply typifies dozens of articles. Marketing can sell SUV's as "Sexy" ... and DRL's can be sold as "safe". The reality is that profit is the reason for both. A behemoth yields more profit, and extra goodies (like DRL's) yield more profit.

.

Thanks for that! I recall (History Channel?) that one can make a medium battle tank disappear by using an array of white lights pointed toward the receiver. At the very least, that suggests that while DRLs can help in some conditions, they might not be best all the time.

 

[EVDRIVER]

Battery-Cell Management - a difficult task:

<snips>

The Quick-Charge ("L3") apparently stops without spending time trying to "balance", so the more conservate 80%-charge figure is given. In fact, with a well-balanced battery pack, there is no good reason that a Rapid-Charge could not get a 90%, or even 95% charge.

Maybe, Gary. It sounds like you're describing 'top balancing' where the system must completely fill each cell to the designated 'max'. There are other methods available for balancing - some of these made easier by the more lead-acid-like slope of the LiMn charge/discharge curve over the relatively flat curve of LiFePO4 or LiPo. If the car is monitoring the capacity of each parallel group, for example, it can shuttle energy around so the pack's balanced at, say, 60%. We have no indication that Nissan's actually doing that, though - just like we really don't know if they're top balancing.

What's more likely - and what's already been done with earlier cars - is that the system will keep voltages in check day to day while allowing everything else to shift a bit with time. When the pack and car's computer get out of sync, the car will likely call for service (throw an error code) and we'll (er, I mean the dealer tech...) will follow the discharge/recharge re-sync process in the shop. This is required now for things like laptop computer packs and earlier EVs like the Ranger and S10. Here's an example procedure.

I don't agree with your assessment of a 90 or 95% quick charge - even if only talking 90-95% of the smaller 'user' charge range - solely because of heat.

Pack balancing is not something that's going to be left to us users - we don't have to think about it or worry about it. We don't even have access to the top or bottom range of the pack - so top- or bottom-balancing isn't even something we can do! Best we can do is label it "FM" (freakin' magic) and move on.

The reason they give 80% is likely the charger can hammer the pack to about that level safely before it needs to throttle back quite a bit causing the charge curve to slow, so claiming a higher percentage would require a MUCH longer charge time. As a inaccurate example, 30 min to 80% then 45 min to 90% etc. This was typical in many EVS and that's why charger companies list fast times to 80%, once you go past this the regulators/BMS will kick in insuring you pull back the hammer on the charger which increases the time curve. I have adjusted many regulators and having the reg talk to the charger allows for max current on each given charge. Claiming an 80% number makes sense, your assumptions are not correct Gary for L3 charging unfortunately. Anyone who has adjusted a BMS on a larger pack with a high power charger understands why these percentages are used.

You can take a large high-current AC feed with a rectifier and hit a low pack full tilt as long as you cut the charge far before some modules begin to get too full, this is know as a "bad boy" charger and is quick and dirty and can charge a pack without an expensive charger and without issue IF you know how to use it properly.

 

[DaveinOlyWA]

Although the technology Is different. Most batteries charge Pretty much the same. On my Zenn. It would start out At around 12 amps N run for a few hours. Pack voltage would be Around 85 volts 4 6-12 volt batteries. Then the current Will start to drop. The voltage Will eventually rise To around 88 to 89 volts. This part takes At least an hour. It does not matter if the full charge part lasted 30 minutes or 3 hours the end always goes an additional hour.

Many many times I have taken off When the current was down too 2-3 amps and i was probably at 95 percent plus with out having to go the aditional 45 minutes

 

[EVDRIVER]

Although the technology Is different. Most batteries charge Pretty much the same. On my Zenn. It would start out At around 12 amps N run for a few hours. Pack voltage would be Around 85 volts 4 6-12 volt batteries. Then the current Will start to drop. The voltage Will eventually rise To around 88 to 89 volts. This part takes At least an hour. It does not matter if the full charge part lasted 30 minutes or 3 hours the end always goes an additional hour.

Many many times I have taken off When the current was down too 2-3 amps and i was probably at 95 percent plus with out having to go the aditional 45 minutes

Your zen does not use high current charging, and you have no BMS, you are likely using gel cells as well. There is a big difference in a large HV pack with a high-current charger and BMS.

 

[LEAFfan]

I bet it won't work with my garage opener. Its a 25yr old Sears single frequency model :lol:

We've had several home-link equipped cars in the past 10 years work with a 20 year old single-frequency garage door opener.

Ok, I need someone to tell me how I can make the 'light' button work on the remote. There is a button on the wall/main that I can turn it on and off, but it isn't connected to my remote opener. My remote has 3 buttons on it, one for the door, one for the light, and prob one for a gate which I wouldn't need. Thanks!

 

[EVDRIVER]

I bet it won't work with my garage opener. Its a 25yr old Sears single frequency model :lol:

We've had several home-link equipped cars in the past 10 years work with a 20 year old single-frequency garage door opener.

Ok, I need someone to tell me how I can make the 'light' button work on the remote. There is a button on the wall/main that I can turn it on and off, but it isn't connected to my remote opener. My remote has 3 buttons on it, one for the door, one for the light, and prob one for a gate which I wouldn't need. Thanks!

Google---

 

[johnr]

If the solar panel spoiler powers a ventilation fan to keep the car cool while parked in the sun, it would almost be worth the extra $700 just for that! But sadly, we don't really know if it does such a thing or not...

Aside from that, I don't really have a desire for the other features so for now I'm sticking with the SV trim.

 

[LakeLeaf]

If the solar panel spoiler powers a ventilation fan to keep the car cool while parked in the sun, it would almost be worth the extra $700 just for that! But sadly, we don't really know if it does such a thing or not...

If it does - you would have to add that fan to the motor count thread

 

[garygid]

With 50 years of EE and recent experience with all-cell monitoring of a LiFePO4 "pack" during charging, I am familiar with most of the charging issues.

1. MOST likely, some "BMS" inside the car will tell the external "L3" DC power source when to quit.
2. It is also most likely that the LEAF's internal "QC-Control" will specify how much current to "force" into the battery pack, and when to reduce that current, eventually to "zero" (charging finished).
3. Most likely that "stopping" point will be based on the highest cell voltage.
4. If the cells are well balanced, the pack would then be at a higher SOC than if the cells are un-balanced.
5. Yes, there are other ways to "regulate" (do) Quick-Charging, but most others take some risks with over-charging an "already-high" cell.

No, I do NOT know what Nissan's LEAF will do, and I do not know what the EV-to-QC station communication "standards" do/will include.

 

[LEAFguy]

I believe that I saw in an edmunds.com article that Mark Perry said to expect 80% in less than 30 minutes (L3), with the remaining 20% taking up to 90 minutes. Don't have time right now to go find the source (edmunds has a really inefficient search system).

 

[LEAFfan]

I believe that I saw in an edmunds.com article that Mark Perry said to expect 80% in less than 30 minutes (L3), with the remaining 20% taking up to 90 minutes. Don't have time right now to go find the source (edmunds has a really inefficient search system).

Ah, so now I'm wondering if you just do the quick 80%, then disconnect, will it still be harmful to your batteries? Or does most of the harm come from DC charging for the next 90 minutes?

 

[LEAFguy]

Ah, so now I'm wondering if you just do the quick 80%, then disconnect, will it still be harmful to your batteries? Or does most of the harm come from DC charging for the next 90 minutes?

Now that... is a really good question!

 

[DaveinOlyWA]

According to the New thread on range expectations, it's recommended that fast charging only be done no more than once per day

 

[garygid]

Probably OK to do the QC more often if in a not-too-hot climate.

In driving to San Diego, I would need to QC once on the way there, possibly once "around town", and once on the way back.

Going to Seattle, I would need to QC about 5 to 7 times each day, probably for 3 days. It is about 1100 to 1200 miles if there are no side trips.

 

[LEAFfan]

According to the New thread on range expectations, it's recommended that fast charging only be done no more than once per day

That's my question: Do they mean 80% or full fast charging?

 

[DaveinOlyWA]

They do not specify. Look it with a prius. Charge levels run from 40 percent to 80 percent.

So maybe the warning is not a fast charge to 100%.

Also the temperature issues are valid as well. all batteries heat up when charging. the faster charge the greater the heat build up

Another thing to think about, scenarios where fast charging is required would equate to nearly 3 hours of drive/charge. Time