Jesla or Leviton EVB40-PST

[kiwiguy]

Assuming the adaptor is a passive device you could just wire it across the appropriate legs of the terminals. You could even make your own adapters knowing the right resistance.

REMINDER: This is all theory. I don't know what I'm taking about. Tony would know better.

 

[TonyWilliams]

Assuming the adaptor is a passive device you could just wire it across the appropriate legs of the terminals. You could even make your own adapters knowing the right resistance.

REMINDER: This is all theory. I don't know what I'm taking about. Tony would know better.

Yes, you could run the parallel resistor between the communication pin and ground on the outside of the plug (no need to cut open).

Here's a simple formula that I stole off the internet to determine to total resistance measured in ohms from multiple resistors IN PARALLEL only:

RT = Resistance Total

1/R total = 1/R1 + 1/R2 + 1/R3, etc.

So,

R1 = 33k Ω

R2 = 36k Ω



1/RT = 1/33k + 1/36k

1/RT = 36k/1,188,000k + 33k/1,188,000k

1/RT = 69k/1,188,000k

1/RT = 0.00005808

RT = 17.2k Ω

The total resistance is 17.2k Ω


That should be about 32 amps.

********

Tesla UMC Plugs Resistance

40 amps - 9.08k ohms

24 amps - 33.16k ohms

16 amps - 75k ohms

12 amps - 140k ohms

 

[rickrides]

Assuming the adaptor is a passive device you could just wire it across the appropriate legs of the terminals. You could even make your own adapters knowing the right resistance.

REMINDER: This is all theory. I don't know what I'm taking about. Tony would know better.

Yes, you could run the parallel resistor between the communication pin and ground on the outside of the plug (no need to cut open).

Here's a simple formula that I stole off the internet to determine to total resistance measured in ohms from multiple resistors IN PARALLEL only:

RT = Resistance Total

1/R total = 1/R1 + 1/R2 + 1/R3, etc.


So,

R1 = 33k Ω

R2 = 36k Ω



1/RT = 1/33k + 1/36k

1/RT = 36k/1,188,000k + 33k/1,188,000k

1/RT = 69k/1,188,000k

1/RT = 0.00005808

RT = 17.2k Ω

The total resistance is 17.2k Ω


That should be about 32 amps.

********

Tesla UMC Plugs Resistance

40 amps - 9.08k ohms

24 amps - 33.16k ohms

16 amps - 75k ohms

12 amps - 140k ohms

I don't see how you could wire in an external resister the way the adaptor and UMC are physically designed. Easy in theory but not in practice.

 

[rickrides]

What are the most needed adapters for the Jesla when on the road? Of course I already have the 5-15 and 14-50.

 

[TonyWilliams]

What are the most needed adapters for the Jesla when on the road? Of course I already have the 5-15 and 14-50.

I would carry them all, plus the adapters recommended on this thread:

http://www.myrav4ev.com/forum/viewtopic.php?p=16425#p16425

 

[fooljoe]

What are the most needed adapters for the Jesla when on the road? Of course I already have the 5-15 and 14-50.

I would just make sure you have at least one for each possible amperage setting (so 12, 15, 24, and 40), then you could make your own adapters to go from those to any other outlets you might encounter. Or of course you could just figure out the resistor thing and all you'd need would be pigtail with a 14-50r end and a bunch of possible plug ends you could attach in a pinch.

 

[rickrides]

What are the most needed adapters for the Jesla when on the road? Of course I already have the 5-15 and 14-50.

Or of course you could just figure out the resistor thing and all you'd need would be pigtail with a 14-50r end and a bunch of possible plug ends you could attach in a pinch.

I don't see any way to connect a resistor to the communication lead. The ground is easy but those pins between the adapter and Tesla plug are very well protected when plugged together.

I might get a 14-30 adapter and make a pigtail with a 10-30p to 14-30r. I figure that will cost about $30 which saves about $20 over the smaller and cleaner 10-30 adapter. I guess $20 saving for the multiple different outlets will add up.

 

[fromport]

What are the most needed adapters for the Jesla when on the road? Of course I already have the 5-15 and 14-50.

Or of course you could just figure out the resistor thing and all you'd need would be pigtail with a 14-50r end and a bunch of possible plug ends you could attach in a pinch.

I don't see any way to connect a resistor to the communication lead. The ground is easy but those pins between the adapter and Tesla plug are very well protected when plugged together.

I might get a 14-30 adapter and make a pigtail with a 10-30p to 14-30r. I figure that will cost about $30 which saves about $20 over the smaller and cleaner 10-30 adapter. I guess $20 saving for the multiple different outlets will add up.

Why not modify the jesla with a X way switch and hardware X resistors so the user can use the X different amp settings ? Could be as easy in some kind of pigtail before the 14-50 plug
with another 14-50 pigtail at the other end.
no physical modification of the jesla, and for smart people, enough to choose from ;-)

 

[davewill]

Why not modify the jesla with a X way switch and hardware X resistors so the user can use the X different amp settings ? Could be as easy in some kind of pigtail before the 14-50 plug
with another 14-50 pigtail at the other end.
no physical modification of the jesla, and for smart people, enough to choose from ;-)

The signal in question is only between the Tesla adapter and the main case of the Jesla. I'd be tempted to do a mod inside the main case. Use a rotary switch to select an amperage, plus one switch to let the one on the adapter's setting through instead. You could also do it inside a 14-50 adapter, if you can get it open and there's enough space inside. Then you just need the rotary switch to select the different amperages. An advantage to doing it in the adapter is that to make the mod go away, you just buy a new adapter.

P.S. Another nice thing about doing it in the adapter is that someone could start a small business modding and selling 14-50 adapters.

 

[Dsinned]

Since I believe the JESLA is rated for 40A thru the J1772 output cable, why not just let the EV's OBC determine how much AC current will be allow at either L1 or L2 EVSE charging? I think resistor modifications in these already expensive TESLA input AC adapters is totally unnecessary provided the EVSE (or the car) has the means to set the current limitations. The EV community is a fairly well informed bunch, I don't think we need to have charging equipment that is totally "idiot proof"!

 

[rickrides]

Since I believe the JESLA is rated for 40A thru the J1772 output cable, why not just let the EV's OBC determine how much AC current will be allow at either L1 or L2 EVSE charging? I think resistor modifications in these already expensive TESLA input AC adapters is totally unnecessary provided the EVSE (or the car) has the means to set the current limitations. The EV community is a fairly well informed bunch, I don't think we need to have charging equipment that is totally "idiot proof"!

If you use the 14-50 adapter on the jesla and use a 14-30p to 14-50r pigtail and plug into a 30a dryer outlet, the jesla will try to pull 40a from the 30a circuit because of the resistance in the 14-50 adapter. You have to tell the jesla how many amps to pull by the resistance to ground on the communication lead . Each adapter has a specific resistance. The lower the resistance the lower the current.

Tony, correct me if I'm wrong.

BTW, nobody has said how to get to the communication lead without cutting open the plug or UMC box. The only way I see is to slice the cord open and run it thru a box with a switch that selects the resistance for the correct current.

 

[TonyWilliams]

Tony, correct me if I'm wrong.

BTW, nobody has said how to get to the communication lead without cutting open the plug or UMC box. The only way I see is to slice the cord open and run it thru a box with a switch that selects the resistance for the correct current.

I honestly don't have time to experiment with this, but I can think of many ways to try.

I might play with it one night when I have nothing to do.

 

[jimbo69ny]

This is why I prefer the openevse units. There is a button to change the amperage manually. It's quick and easy.

The Jesla is a nice option, I just prefer the openevse's because of their ease to change amperage.

 

[rickrides]

The Jesla is a very well made unit. It's small, has rounded corners, is light weight, the case is molded rubber and is very portable. The cord is relatively light and flexible. The adapters are also small and have a thin molded rubber cover. The downside is the cost and not able to charge at 32a. It would be nice if the adapters were ~$25.

 

[Dsinned]

As the title to this thread suggests, if all we are comparing are JESLA vs. Leviton, with both rated for 40A L2 charging, and comparable in price, I believe the JESLA would be the overall winner! Of course, there are many other contenders, and seemingly more attractive at nearly half the price, (and other thread to read about those), but the OP apparently only wants to know which of these TWO is the better choice. The short answer is JESLA!

 

[jscgvnc]

The short answer is JESLA!

I'd have to agree. I have a Leviton 40A unit, and I wish I had gotten the JESLA instead.

It's just more useful to throw it in the car and be able to drive around with it. At the time, I didn't know the JESLA was an option, so that's my excuse. We had a car failure and had to move faster than I wanted, and I bought the Leviton because that's what Toyota told me to get. That being said, I do like the Leviton, in that it's never had a problem.

I have the one with the plug on back of it(as opposed to hard-wired), and I have taken it with me a few times, when I went to my parents house and knew I could plug it in. It's not very heavy.

I'm currently saving my pennies to buy a JESLA as well.