Is there an EVSE capapble of charging my Leaf to a set percentage?

[AndyGT02]

I'm tired of the charge delay function in the '15 Leaf S being so inaccurate. I want to leave for work in the morning with my car at 70%. Instead, because of the way the delay timer works in relation to the battery level when it was last parked, my car is either approaching 100%, or hasn't started charging yet (leaving me below 70%).

Are there any EVSE's that are able to monitor the Leaf and stop charging at a set point? Or, at the very least, can be set to stop charging after a certain amount of electricity has been dispensed?

 

[cwerdna]

Seems unlikely given that there’s nothing in the J1772 protocol for the car to tell the EVSE the car’s state of charge. See https://code.google.com/p/open-evse/wiki/J1772Basics.

A possibility is to use an EVSE w/its own timer. I hear Siemens VersiCharge units have some sort of (delay?) timer.

http://www.chargepoint.com/home/general/ says "The majority of home stations don't have the ability to schedule charging and the ones that do have limited scheduling options. Home is 100% configurable."

 

[Graffi]

I recommend that you just start the charge when you get home and then stop it after a certain amount of time. If you have a 240v EVSE then you are charging at 6.6kw rate. For me I figure it charges 24 miles each hour, so 4 miles each 10 minutes. If you need to add about 20 miles to the car then leave it charging for 50 minutes.

If you have 120v then you need to calculate how long to let it charge.

Hope this helps.

I'm tired of the charge delay function in the '15 Leaf S being so inaccurate. I want to leave for work in the morning with my car at 70%. Instead, because of the way the delay timer works in relation to the battery level when it was last parked, my car is either approaching 100%, or hasn't started charging yet (leaving me below 70%).

Are there any EVSE's that are able to monitor the Leaf and stop charging at a set point? Or, at the very least, can be set to stop charging after a certain amount of electricity has been dispensed?

 

[AndyGT02]

Thanks

 

[cwerdna]

I personally wouldn’t think of miles, since efficiency in miles/kWh is much better at low speeds than high.

If you have a 6.6 kW OBC and you have a 240 volt 30 amp EVSE, then figure ~6 kW makes it into the battery, after charging losses. So, in 1 hour, ~6 kWh made it in. In 2 hours, ~12 kWh. Leaf on a new battery has about ~21 to 22 kWh usable.

Of course, in the last hour when going to 100%, little energy makes it into the battery as charging power has ramped down and it will be in bounce phase (see graph at http://www.mynissanleaf.com/viewtopic.php?p=338038#p338038).

 

[LeftieBiker]

L-1 adds just over 5% per hour of charge - very easy to estimate. The charge rate for L-2 depends on the amperage provided by the EVSE. I think I calculated that my 20 amp Clipper Creek unit would add 20% per hour, excepting the tapering in the last 15 minutes or so. In your case a 20 amp unit might actually be better, as the margin for error would be larger than it would for a faster 30 amp unit.

 

[Valdemar]

Sounds like we need a new Leaf Spy Pro feature for it to be able to act as a charge timer with arbitrary SOC selection? Are there CAN commands it can send to start/stop charging?

 

[camasleaf]

Sounds like we need a new Leaf Spy Pro feature for it to be able to act as a charge timer with arbitrary SOC selection? Are there CAN commands it can send to start/stop charging?

Could Leaf Spy Pro read the SOC from the car and send start/stop to EVSE over Wifi?

 

[Valdemar]

Sounds like we need a new Leaf Spy Pro feature for it to be able to act as a charge timer with arbitrary SOC selection? Are there CAN commands it can send to start/stop charging?

Could Leaf Spy Pro read the SOC from the car and send start/stop to EVSE over Wifi?

Is there a EVSE with wi-fi and known command protocol? I think a CAN-only approach would be more generic as it is not tied to a particular EVSE.

 

[TonyWilliams]

Wifi isn't necessarily needed. It could be a simple wire.

So, let's imagine we use JLong with an extra jumper wire across the disconnect switch in the handle. Now, a simple CAN bus reader that hits a programmed SOC% opens a relay which exposes the proximity pin to 330 ohms.

That's it. Works with any EVSE.

 

[knightmb]

If home ChaDeMo chargers existed, in theory those could

 

[edatoakrun]

If home ChaDeMo chargers existed, in theory those could

Yet another reason why it is foolish to place BEV/PHEV/BEVx chargers on-board in the first place.

Take my on-board charger...PLEASE!

Having the charger in-car is really not a convenience, it imposes multiple limitations. on BEVs.

Where kW rates are available at the charge site at higher rates than the on-board charger, the slower onboard charger is only a bottleneck preventing faster charging. It often prevents the desirable kW rate for any BEV/BEVx/PHEV at any charge site, which is either the maximum the grid infrastructure at that location supports, and (far less frequently) the maximum the battery will accept (~48 kW for A ~24 kW pack like the LEAF's) both subject to kW cost/rate considerations.

An on-board charger can not be used to charge other BEVs/BEVxs/PHEVs (yours, or other drivers') while you are not using it, making its use extremely costly and inefficient, by requiring us to collectively pay for many more chargers than are necessary to service all BEVs public charging requirements.

An on-board charger adds large additional costs, weight an complexity to BEVs/BEVxs/PHEVs, and almost all of them probably will have to be thrown away, after the rest of each BEV/BEVx/PHEV reaches the end of its useful life.

An on-board charger will never allow vehicle-to-grid or vehicle-to-home kW transfer, which a two-way DC device will be able to, which can add additional value to the significant investment (the bigger the pack, the greater the benefit) every BEV/BEVx/PHEV owner has made in their battery pack, and in the case of BEVxs and PHEVs, add value to their on-board ICE as well.

The "waste" heat produced from the on-board charger is not recoverable, while, if the on-site charger is properly located, this heat can be recovered to meet the needs of the human passenger's activities, while they are charging.

As I mentioned before, before the transition to on-site chargers is complete, you may want to carry a portable charger with you, especially when driving in remote areas.

At some point in the future though, I expect that notion will probably seam about as quaint as carrying your own fuel pump and hose with you, just in case the gas station you are headed to doesn't have any fuel pumps on-site...

http://www.mynissanleaf.com/viewtopic.php?f=26&t=19953

I also have a descent (~1,500 ft. net in ~7 miles) on most trips from home, and the inability to set a charge level below 100% in a newer LEAF is a major disadvantage, compared to my 2011 LEAF.

Obviously, a single charger in the garage with DC plugs, programmable for the various preferred end SOCs for all the vehicles charging there, would be far superior to having to have multiple limited kW chargers installed in each vehicle.

 

[TonyWilliams]

If home ChaDeMo chargers existed, in theory those could

Well, that's probably the absolute most expensive way to solve this problem!

 

[knightmb]

If home ChaDeMo chargers existed, in theory those could

Well, that's probably the absolute most expensive way to solve this problem!

True, but you wouldn't need a ChaDeMo that did 50kW of power, if it did 6kW like the typical L2 does, it could be used in a garage and not cost as much since it won't require such heavy duty AC-DC conversion, hardware, etc. All with the benefits of programmable charge settings taken directly from the vehicle.

 

[Valdemar]

If home ChaDeMo chargers existed, in theory those could

Well, that's probably the absolute most expensive way to solve this problem!

True, but you wouldn't need a ChaDeMo that did 50kW of power, if it did 6kW like the typical L2 does, it could be used in a garage and not cost as much since it won't require such heavy duty AC-DC conversion, hardware, etc. All with the benefits of programmable charge settings taken directly from the vehicle.

Still you're looking at 3-4x cost of a regular EVSE in the most optimistic scenario, just consider the cost of the Chademo plug by itself.

 

[TonyWilliams]

If home ChaDeMo chargers existed, in theory those could

Well, that's probably the absolute most expensive way to solve this problem!

True, but you wouldn't need a ChaDeMo that did 50kW of power, if it did 6kW like the typical L2 does, it could be used in a garage and not cost as much since it won't require such heavy duty AC-DC conversion, hardware, etc. All with the benefits of programmable charge settings taken directly from the vehicle.

So, just to be clear, the original question was how to limit charge to a % of SOC. I spec'd that out with less than $100 in parts.

Building or buying an entirely different charging method at thousands of dollars in cost to "solve" this problem is insanity.

 

[knightmb]

So, just to be clear, the original question was how to limit charge to a % of SOC. I spec'd that out with less than $100 in parts.

Building or buying an entirely different charging method at thousands of dollars in cost to "solve" this problem is insanity.

It's useful for anyone that ask in the future why they waste money putting the charger in the car. The answer is, it would make the chargers at home cost a lot more money than they do now. :mrgreen:

 

[TonyWilliams]

So, just to be clear, the original question was how to limit charge to a % of SOC. I spec'd that out with less than $100 in parts.

Building or buying an entirely different charging method at thousands of dollars in cost to "solve" this problem is insanity.

It's useful for anyone that ask in the future why they waste money putting the charger in the car. The answer is, it would make the chargers at home cost a lot more money than they do now. :mrgreen:

Hey, knock yourself out! Go rip out that bad onboard charger, and build / buy a CHAdeMO for home use.

I do think that low cost FUTURE EVs (in 20 or more years) won't have onboard chargers as standard equipment, but any optional onboard charging will be wireless. DC conductive charging will "standard", in cheap low powered DC chargers at home.

None of this has any bearing on the issue at hand... restricting charge based on SOC%.

 

[cwerdna]

A possibility is to use an EVSE w/its own timer. I hear Siemens VersiCharge units have some sort of (delay?) timer.

There's some recent chatter about this on the BMW i3 Facebook group (https://www.facebook.com/groups/BMWi3/permalink/952396414834220/?comment_id=952485094825352&comment_tracking=%7B%22tn%22%3A%22R0%22%7D). They mention a 2-4-6-8 (hour) charging delay button.

 

[asimba2]

I am using OpenEVSE and couldn't be happier with a semi-recent firmware update that added the ability to charge for a specific amount of time. It's not what the OP is looking for, but as LeftieBiker said, at 20 amps the EVSE adds about 20% of charge per hour. When I plug in my Leaf, I can set the EVSE to run the timer at 15 minute intervals, then it kicks off. If I need 60% and only have 40% charge, I just cycle the charge time menu on the OpenEVSE to tell it to charge for 15 minutes. I love this feature. Much better than setting the timer on my microwave to remind me to unplug the car.