120v charging and Preconditioning

[amped]

Hey guys Jamez's friend here.

So my problem is at my rental (where I stay during the weekdays) I won't be able to install a level 2 charger due to landlord issues, pre-war 1910 built home (our dryer runs off of 120V, kill me now) but I will install one at my actual home (in another city and where I stay during the weekend). Money is not the issue here.. unless you're telling me to buy a second house lol.

If your electrical service is really old and hasn't been updated in ages, make sure that the 120v outlet(s) you want to use actually has a ground (no ungrounded 3-prong receptacles or ungrounded GFCI receptacles). The EVSE pilot signal requires an equipment ground to function properly. Also, make sure it can handle 8h+ at 12 amps. I can just imagine some past renovations daisy-chaining a huge number of outlets together on a single circuit.

 

[Thaid]

The Turbo cord is a good idea though, but I'd probably end up with something like vegas' makes (dude, you gotta update that site)
https://www.bsaelectronics.com/products/evse2-30a-7-2kw-openevse-portable-waterproof-with-lcd-15ft-bsa-custom-j1772-cable?variant=1680698753

Yeah, I almost bought some stuff from him in Dec but he had a huge backlog and I needed it ASAP. He seems to still have the winter sale going on for the portable 16amp L2 EVSE.

I would also like to point out that OpenEVSE.com is now starting to sell some of their kits pre-assembled with a 3yr warranty.
e.g. https://store.openevse.com/products/copy-of-model-p50a-advanced-40a-charging-station-powered-by-openevse

I believe most of vegasbrad's EVSEs are based on OpenEVSE components/design.

Correct me if im wrong, but those EVSE kits only require that higher amp plug right? Eliminating the need for a fixed charging station?

 

[amped]

The pre-assembled OpenEVSE kits come with a NEMA 14-50 plug & cord for portable use. Cord is easy to remove if you want to hardwire it. I'm sure vegasbrad would put whatever kind of cord/plug you want on one of his EVSEs.

 

[triangles]

The Turbo cord is a good idea though, but I'd probably end up with something like vegas' makes (dude, you gotta update that site)
https://www.bsaelectronics.com/products/evse2-30a-7-2kw-openevse-portable-waterproof-with-lcd-15ft-bsa-custom-j1772-cable?variant=1680698753

Yeah, I almost bought some stuff from him in Dec but he had a huge backlog and I needed it ASAP. He seems to still have the winter sale going on for the portable 16amp L2 EVSE.

I would also like to point out that OpenEVSE.com is now starting to sell some of their kits pre-assembled with a 3yr warranty.
e.g. https://store.openevse.com/products/copy-of-model-p50a-advanced-40a-charging-station-powered-by-openevse

I believe most of vegasbrad's EVSEs are based on OpenEVSE components/design.

Correct me if im wrong, but those EVSE kits only require that higher amp plug right? Eliminating the need for a fixed charging station?

Just to clear things up charger wise for you. The FFE's charger works as follows: On 120V it will charge at up to 12A, this is 1.44kW max charge rate. On 240V it will charge at up to 27.5A for 6.6kW max charge rate. So it will charge a little over 4 1/2 times faster on 240.

If you buy or build a portable L2 charge station (EVSE) you need to be aware of what current your EVSE tells the car it can charge at. For example some 240V Turbo Cords charge at 16A (3.8kW). The Open EVSE kits can be configured to different current settings. The big thing to remember is you do not want to exceed 80% of the current rating for whatever you're plugged into. For example 240v dryer plugs are typically 30A outlets. 240V oven's are typically 50A. So for these two plugs your EVSE must not exceed 24A and 40A respectively. The 80% rule is there to prevent you from burning down the house. The turbo cord being only 16A will work in just about any 240V outlet you'd ever encounter. It may not be the fastest but it gives the versatility to plug into any 240V outlet and not worry about overloading it. There's plenty of info on here about various adapters and plug types if you want to know more. I was speaking in general terms to keep things simple.

If you can get any sort of 240V outlet even if it's only 20A You will be far ahead of being stuck with the 120V charging. If you want to get a relative idea of different charging speeds at various voltages and currents, simply multiply volts times current (amps) to get Watts (1000 Watts = 1kW) 6,600Watts or 6.6kW will be your fastest charging time and 1,440W or 1.44kW will be your slowest charging at 120V. In theory you can charge slower than 1.44kW but why would you want to? If the early 1900's wiring can't accommodate any 240.... then it's time to find a different place to stay during the week!! :lol:

 

[amped]

Just to clear things up charger wise for you. The FFE's charger works as follows: On 120V it will charge at up to 12A, this is 1.44kW max charge rate. On 240V it will charge at up to 27.5A for 6.6kW max charge rate. So it will charge a little over 4 1/2 times faster on 240.

I wonder about this. I was stupidly playing around with the rapi interface on my OpenEVSE via wifi when a typo I entered caused the max current limit to reset to the default in the firmware (80A, IIRC). The car had been charging for a while when this happened and the displayed current shot up to just shy of 30A and almost tripped the 30A breaker (i.e. buzzing). I suppose my current sensor could be miscalibrated, but I'm thinking the 6.6kw rating may refer to DC output - or maybe it's AC input at 220v). Are there definitive technical specs available for the FFE unit? Maybe some one else with a current display on their EVSE can weigh in. If it's an output rating or 220v input rating, then the car might pull closer to 30 amps (~7.2kw AC at 240v). In that case, max level 2 at 240v could be closer to 5 times faster than level 1 at 120v.

If you buy or build a portable L2 charge station (EVSE) you need to be aware of what current your EVSE tells the car it can charge at. For example some 240V Turbo Cords charge at 16A (3.8kW). The Open EVSE kits can be configured to different current settings. The big thing to remember is you do not want to exceed 80% of the current rating for whatever you're plugged into. For example 240v dryer plugs are typically 30A outlets. 240V oven's are typically 50A. So for these two plugs your EVSE must not exceed 24A and 40A respectively. The 80% rule is there to prevent you from burning down the house. The turbo cord being only 16A will work in just about any 240V outlet you'd ever encounter. It may not be the fastest but it gives the versatility to plug into any 240V outlet and not worry about overloading it. There's plenty of info on here about various adapters and plug types if you want to know more. I was speaking in general terms to keep things simple.

That 80% rule is for continuous loads (~3+ hours, IIRC), which would be the case for a full 0-100% recharge at level 2 but not for the more typical top up. Code compliance and permitting probably require derating for any EVSE installation no matter what the intended usage since it COULD be used for >3h. Exceeding 80% for short periods shouldn't be unsafe but I would worry about forgetting to adjust the current down when plugging in for a longer charge.

If the early 1900's wiring can't accommodate any 240.... then it's time to find a different place to stay during the week!! :lol:

I hope it was updated at some point. If it's original pre-WWI stuff, there is probably no proper equipment ground and even the level 1 won't work.

 

[jmueller065]

I believe that the 6.6kW rating is the amount of power the charger pushes into the battery, not the amount of power it consumes from the wall (indeed if you take 6.6kW/0.90 you get ~7.3kW--assuming its 90% efficient).

 

[triangles]

Maybe some one else with a current display on their EVSE can weigh in. If it's an output rating or 220v input rating, then the car might pull closer to 30 amps (~7.2kw AC at 240v). In that case, max level 2 at 240v could be closer to 5 times faster than level 1 at 120v.

My 240 Volt line measures at 249V and doesn't really drop under load. When charging at full current draw the display on my JuiceBox EVSE flips between 28A-29A so I can infer it's about 28.5A constant draw. So at 249V the most my car pulls is 7.0965 or 7.1kW Ford says it's a 6.6kW charger. I don't know if that means that's what it can feed the battery but guess that makes sense as I would have about 500W of heat lost in the energy conversion (7.1kW-6.6kW = 500W). I also have no idea how accurate the JuiceBox is at measuring current so that could be a source of wild inaccuracy.

 

[amped]

My line voltage is 245v. Just tested my OpenEVSE unit again by increasing max current to 32A. Current draw tops out at a steady 29.7A, so ~7.3kw if current reading is accurate.