[Fidel]

Hi,
I just bought a 2018 Honda Clarity charging cable rated NEMA 10-30
that actually charges at 16 Amps. I'm using also a NEMA 10-30 extension cord. The service panel in the house has a 30 Amps for this outlet. It takes about 4 hours to fully charge the vehicle's electric battery.
I just noticed that the cable EVSE unit gets too hot after the first hour of charging. And remains hot until the full charge is completed. Neither the extension cord, nor the point of contact between the extension cord and the charging cable gets hot. It's only the EVSE unit and to some extent the cord going from the EVSE unit to the car.
Is this a normal situation to get the EVSE unit pretty hot in this charging cable? Or should I be concerned and do something about it? And if so, what are my options?
Please, anyone with knowledge about this situation be so kind to tell me what can be done.
Thank you!

 

[DucRider]

An EVSE shouldn't get hot as it is just (essentially) a relay that sends current to the charger (in the car) when all safety parameters have been satisfied. Is the EVSE from a reputable vendor and UL/CSA/ETL listed? "Too hot" is relative, but implies that it would be uncomfortable to touch it? Excess heat is the sign of bad connections and/or undersized components.
Some EVSE cords do get a little hot if they are sized to be "just enough" to carry the load. This is usually done to save weight, cost, and make them easier to handle.

 

[tommyboy]

I had that problem with heat on my 16A charger. When I changed out the wiring (to 8GA) and a 40A breaker to accommodate a new 32A charger my heat problems disappeared and my charging time dropped to 2.5 hours from zero.

 

[EV Nerd]

I had that problem with heat on my 16A charger. When I changed out the wiring (to 8GA) and a 40A breaker to accommodate a new 32A charger my heat problems disappeared and my charging time dropped to 2.5 hours from zero.

Beefing up the wire and breaker on the circuit wouldn't have any effect on an overheating EVSE on an extension cord.

 

[tommyboy]

All I know is this unit is barely even warm when in use.

 

[fotomoto]

I just noticed that the cable EVSE unit gets too hot after the first hour of charging.

Define “too hot”.

 

[tommyboy]

Well, the 16A charger was never a problem with the Prius Prime but when I used it in the Clarity it got so hot it delaminated the faceplate from the unit.

 

[Fidel]

An EVSE shouldn't get hot as it is just (essentially) a relay that sends current to the charger (in the car) when all safety parameters have been satisfied. Is the EVSE from a reputable vendor and UL/CSA/ETL listed? "Too hot" is relative, but implies that it would be uncomfortable to touch it? Excess heat is the sign of bad connections and/or undersized components.
Some EVSE cords do get a little hot if they are sized to be "just enough" to carry the load. This is usually done to save weight, cost, and make them easier to handle.

Thank you so much Gary! I appreciate your input.

 

[Fidel]

I had that problem with heat on my 16A charger. When I changed out the wiring (to 8GA) and a 40A breaker to accommodate a new 32A charger my heat problems disappeared and my charging time dropped to 2.5 hours from zero.

Great idea! I've been thinking on changing to to a 32 Amps charger. So you used an 8 size wire? What's the brand name of your 32 Amps charger? Thanks!

 

[tommyboy]

Great idea! I've been thinking on changing to to a 32 Amps charger. So you used an 8 size wire? What's the brand name of your 32 Amps charger? Thanks!

I bought a Lectron 32A unit off Amazon. It uses a nema 14-50 plug (red, black, common and ground). 40A breaker needs an 8ga wire or you get in trouble with the building dept. Inspectors. The unit was $300 plus tax . I added a switch to cut power to the plug. I don't like phantom energy drain and it is a pain to unplug. I wired a 240v 600a motor switch so I just turn it on and off as desired. Since we are on tiered pricing for our electric I charge when I want and have not programmed the start/stop times.

 

[EV Nerd]

Great idea! I've been thinking on changing to to a 32 Amps charger. So you used an 8 size wire? What's the brand name of your 32 Amps charger? Thanks!

Still doesn't address the question about your hot EVSE from the OP. If that EVSE is getting too hot to hold in your hand comfortably, it's defective, and should be replaced.

Upgrading the wall circuit wiring and breaker to carry more current will have no effect on the existing EVSE that's getting "too hot".

 

[tommyboy]

Still doesn't address the question about your hot EVSE from the OP. If that EVSE is getting too hot to hold in your hand comfortably, it's defective, and should be replaced.

Upgrading the wall circuit wiring and breaker to carry more current will have no effect on the existing EVSE that's getting "too hot".

Actually, it was carrying the same 16A load, and never got hot when charging the Prius Prime. It only got hot when charging the Clarity, which was spot on timewise at 4 hours. The new setup fixed the heat issue and charge time is 2 hours or so.

 

[Fidel]

I bought a Lectron 32A unit off Amazon. It uses a nema 14-50 plug (red, black, common and ground). 40A breaker needs an 8ga wire or you get in trouble with the building dept. Inspectors. The unit was $300 plus tax . I added a switch to cut power to the plug. I don't like phantom energy drain and it is a pain to unplug. I wired a 240v 600a motor switch so I just turn it on and off as desired. Since we are on tiered pricing for our electric I charge when I want and have not programmed the start/stop times.

I appreciate very much your response!
Thank you so much!
Have a wonderful day!

 

[EV Nerd]

Actually, it was carrying the same 16A load, and never got hot when charging the Prius Prime. It only got hot when charging the Clarity, which was spot on timewise at 4 hours. The new setup fixed the heat issue and charge time is 2 hours or so.

Again...you're not the poster from the OP. If they update their circuit, it will have no effect, if it's the EVSE itself that's getting hot. Changing the characteristics of the source circuit (to make it capable of more current), will not help the EVSE to run cooler. If the voltage is changed from 120V AC, to 240V AC (on a compatible EVSE), that's a different story.

It's basic electronic circuit stuff. It would be like attaching a higher amp capacity wall cube charger to your phone, and expecting the phone itself to be cooler as it charges.

 

[2002]

Well, the 16A charger was never a problem with the Prius Prime but when I used it in the Clarity it got so hot it delaminated the faceplate from the unit.

Yes I think everyone would agree that is "too hot". Of course not all overheating situations are visible like that. Infrared thermometers cost just over twenty bucks and work well, accurate enough for these purposes. I have had one for years and use it for all kinds of things around the house. Of course they became popular during the pandemic.

My 12 amp OEM EVSE is connected with a heavy duty extension cord, and I have used my thermometer to check the temperature on the EVSE, the cable, the extension cord, and all connections. I think anyone would benefit from using one to check temperatures, but I think for sure anyone using an extension cord and/or adapter should use one. One thing to check, even if nothing feels hot, is to make sure that the temperatures don't rise over time. Of course it is expected that there will be a warmup period of say fifteen or twenty minutes or so, but then the temperatures should stabilize. If the temperature on any component keeps rising for say an hour before stabilizing, that could indicate a problem. I'm guessing on the times that it should take to stabilize, but that's the general concept. What would probably stand out is one component continuing to rise in temperature long after the others have stabilized. The point being it's better to catch a problem early rather than later when it becomes visible.

 

[Fidel]

I bought a Lectron 32A unit off Amazon. It uses a nema 14-50 plug (red, black, common and ground). 40A breaker needs an 8ga wire or you get in trouble with the building dept. Inspectors. The unit was $300 plus tax . I added a switch to cut power to the plug. I don't like phantom energy drain and it is a pain to unplug. I wired a 240v 600a motor switch so I just turn it on and off as desired. Since we are on tiered pricing for our electric I charge when I want and have not programmed the start/stop times.

Thank you very much! I'll look into that and look for a licensed electrician to do the work.
I appreciate your help!

 

[Fidel]

Yes I think everyone would agree that is "too hot". Of course not all overheating situations are visible like that. Infrared thermometers cost just over twenty bucks and work well, accurate enough for these purposes. I have had one for years and use it for all kinds of things around the house. Of course they became popular during the pandemic.

My 12 amp OEM EVSE is connected with a heavy duty extension cord, and I have used my thermometer to check the temperature on the EVSE, the cable, the extension cord, and all connections. I think anyone would benefit from using one to check temperatures, but I think for sure anyone using an extension cord and/or adapter should use one. One thing to check, even if nothing feels hot, is to make sure that the temperatures don't rise over time. Of course it is expected that there will be a warmup period of say fifteen or twenty minutes or so, but then the temperatures should stabilize. If the temperature on any component keeps rising for say an hour before stabilizing, that could indicate a problem. I'm guessing on the times that it should take to stabilize, but that's the general concept. What would probably stand out is one component continuing to rise in temperature long after the others have stabilized. The point being it's better to catch a problem early rather than later when it becomes visible.

Great idea about using the infra-red thermometer to check how hot the EVSE Unit actually gets!! I know it gets pretty hot. But, in reality, I have no idea. This way we'll have a precise number that we can use to define how serious this is, and hopefully, help others, me included, to avoid a burnt electrical cable, and or change this, or avoid using bad-quality chargers. Or, perhaps clarify if the heat being produced falls within normal parameters. I'm so glad there are so many smart and knowledgeable members in our Clarity/Forum Community. Thank you all!

 

[tommyboy]

Follow up. My niece is using the 16A 240V charger on the Prius I sold (gave) her. I installed the breaker (Square D 240 v 40A), wiring and 6-20R plug. The unit is operating properly. Not hot at all and charges the battery in 2 hours. Unsure what happened with me on the Clarity, but glad it works for her.

 

[EV Nerd]

Follow up. My niece is using the 16A 240V charger on the Prius I sold (gave) her. I installed the breaker (Square D 240 v 40A), wiring and 6-20R plug. The unit is operating properly. Not hot at all and charges the battery in 2 hours. Unsure what happened with me on the Clarity, but glad it works for her.

I wonder if the Clarity has an issue with the Pilot signal, and was trying to pull too much current from the EVSE?

 

[Fidel]

Follow up. My niece is using the 16A 240V charger on the Prius I sold (gave) her. I installed the breaker (Square D 240 v 40A), wiring and 6-20R plug. The unit is operating properly. Not hot at all and charges the battery in 2 hours. Unsure what happened with me on the Clarity, but glad it works for her.

Hi,
I was able to buy the infra-red thermometer. And checked the temperarure of the 16A, 240V charger while charging. At the beginning, it read 96.9 F. After 1 hour of charge the temperature rose to 113 F. After 1½ the temperature rose to 117 F. and it remained at this temperature for another 55 minutes or so. At which time the charge was full. I'd like to mention that the temperature in point where the extension cord and the charging cable mert was at 104 F, while the piece that connects to the car only reached 99.5 F.
I must indicate that I'm also using a 30A, 25 ft extension cord from the wall outlet to the charging unit. I also have a 30A braker on this line. I'd appreciate if anybody out there has any idea if these temperatures are within normal parameters, or if these temperatures are an indication of something wrong and I should stop using this charger.
Thank you very much in advance for any feedback you can provide me. I appreciate it very much your input.