Business Charger for Employees

[yuhong]

Standard network voltage is 125Y/216, as this mimics the archaic 125/250 volt DC network almost all such systems replaced. I'm not familiar with anything higher but there's no law against it.

In the EV world, Baker Electric 'Car chargers' in public downtown areas were merely 'Toasters' which dropped the voltage from the nominal 125 to the 84 volts or whatever was required by the car. No rectification necessary as the juice was already DC. Jay Leno showed his, stating he was afraid the thing would burn down the place, and used a modern battery charger for his. Home charging solutions in AC areas 110 years ago were Mercury Arc 'Glass Bottle' rectifiers mounted on a 'shaker' to initially strike the arc. An Inductor past the single-phase power transformer kept the current running past the zero-crossing point so that the arc never needed to be re-struck, it varying at power line frequency between the 2 anodes every half cycle.

Any homes in the 'dc network' area merely used Jay Leno's Toaster.

Thinking about it, I wonder why EV chargers used to be always based on multiples of 220V since the AVCON days.

 

[Bill25cycle]

Thinking about it, I wonder why EV chargers used to be always based on multiples of 220V since the AVCON days.

To be honest I'm not familiar with that, but historically polyphase motors prior to the 1970's in North America were rated 220, 440, and 550 (and 110 volts back when they sold them - not since the 1940's). Single phase motors went to 115 volts around the same time - 1940. I'm not sure the reason, but 3-phase motors 'held on' to the lower voltages longer than anything else. Distribution voltage was officially rated (for power calculations) by the NEC as 115 prior to the 1970's and 120 afterwards. I'm presuming the change in voltage by the utilities was made to minimize the difference between normal radial systems (such as most people have for their homes or apartments), and downtown network services (usually 125). This was made a decade or two before the NEC 'officially' recognized it.

 

[yuhong]

To be honest I'm not familiar with that, but historically polyphase motors prior to the 1970's in North America were rated 220, 440, and 550 (and 110 volts back when they sold them - not since the 1940's). Single phase motors went to 115 volts around the same time - 1940. I'm not sure the reason, but 3-phase motors 'held on' to the lower voltages longer than anything else. Distribution voltage was officially rated (for power calculations) by the NEC as 115 prior to the 1970's and 120 afterwards. I'm presuming the change in voltage by the utilities was made to minimize the difference between normal radial systems (such as most people have for their homes or apartments), and downtown network services (usually 125). This was made a decade or two before the NEC 'officially' recognized it.

I am talking about EV charging back in the 1990s, where AVCON (aka J1772-2001) was designed for "6.6kW" charging based on 220V 30A. Even later, the Leaf had "3.3kW" and "6.6kW" chargers based on 220V 15A and 30A.

 

[Bill25cycle]

I am talking about EV charging back in the 1990s, where AVCON (aka J1772-2001) was designed for "6.6kW" charging based on 220V 30A. Even later, the Leaf had "3.3kW" and "6.6kW" chargers based on 220V 15A and 30A.

Are you stating an 'official nameplated' voltage or did you just surmise the 220 volt rating? Yeah its true, GEN 1 voltec (GM) systems needed 220 volts to get the full capacity, although GEN II systems (allegedly 7.2 kw) need 225 Volts to get the 'rated' power level. But then, those cars will charge at least at 7.7 kw with 240 - (I haven't been able to test my GM with anything higher as of yet). The Tesla Roadster I had would run at 16.8 kw at 240 volts, and modern Teslas used to be advertised as having 10 kw single chargers and 20 kw dual chargers (which would only happen at 250 volts - of course, the car itself COULD be charged at 277 volts - since I never had a 'modern' Tesla I don't know whether the power level plateaued at 20 kw and the current started dropping beyond 250 volts, or if the power level just kept increasing..

Even though the 80 ampere dual charger "S" 's were very popular, its a bit ironic that the battery size has kept increasing and Tesla is starting to release larger vehicles (Model "X", etc) - yet the standard rate has been dropped from 40 amperes to 32 (I'd say due to too many problems with the standard charging cord at 40 amperes, yet of course they'd never admit it), and the absolute maximum charge rate of 48 amperes on ANY Tesla (excepting the SEMI of course).

****update***** Just checked the Tesla website - apparently they have RERELEASED the 72 ampere charger for the 100 kwh vehicles. Too many must have complained that 48 amperes was simply not enough. I'll have to check if the website was just talking about 'historical' vehicles, or whether the 72 ampere product is now newly available again for new customers.

*****update 2**** On the model X portion, the present limitation is still 48 amperes, so the 'charging portion' must therefore refer to charging those USED model 'x' 's that had a 72 ampere charger. They also claim 200 kw (!!!) at the most modern Superchargers.

Yeah there are now SC's available, yet Mr. Musk has warned owners not to hog the local facilities and to charge at home when possible. I privately think he got some backlash from electric utilities threatening to put Demand Fines on residential Tesla customers since most utilities insist that EV's should use the ENTIRE after midnight period (12- 8am). to recharge - since 40 amps at 8 hours is much easier for them to accomodate than 80 amps at 4 hours (PER CAR), and its not a problem if a neighborhood only has 1 or 2 Teslas, yet a subdivision full of 80 ampere Teslas would cause a UTILITY indigestion as having to provide larger facilities for zero additional revenue over each car being 48 amperes maximum - the present limitation. And of course Tesla has handled the multi-car problem by throttling the HPWC to a premises maximum of 24-80 amperes (user selectable) even if the very large home has up to 4 HPWCs.

But 220 volts is usually generous for most public chargers - they being distant from any electrical services and electricians rarely if ever taking into account pressure drop over long distances from the main buildings, such that some here have said they have charged on as low at 183 volts, it is also true that 195-199 volts isn't uncommon at all.

Now as far as the 3.3 kw GEN 1 LEAF was concerned - a friend would get 18 amperes on a horrible public docking station (184 volts). Since Japan is universally 100/200 volts whether in 50 or 60 HZ areas the GEN 1's EXCELLENT low voltage performance was to be expected. Does anyone know whether the 6.6 kw later chargers would draw an analogous 36 amperes? The largest wall box I have is 32 amperes but I have yet to have someone with a GEN 2 Leaf try it out to see if the charger can hack more than 30.

 

[yuhong]

Are you stating an 'official nameplated' voltage or did you just surmise the 220 volt rating? Yeah its true, GEN 1 voltec (GM) systems needed 220 volts to get the full capacity, although GEN II systems (allegedly 7.2 kw) need 225 Volts to get the 'rated' power level. But then, those cars will charge at least at 7.7 kw with 240 - (I haven't been able to test my GM with anything higher as of yet). The Tesla Roadster I had would run at 16.8 kw at 240 volts, and modern Teslas used to be advertised as having 10 kw single chargers and 20 kw dual chargers (which would only happen at 250 volts - of course, the car itself COULD be charged at 277 volts - since I never had a 'modern' Tesla I don't know whether the power level plateaued at 20 kw and the current started dropping beyond 250 volts, or if the power level just kept increasing..

Even though the 80 ampere dual charger "S" 's were very popular, its a bit ironic that the battery size has kept increasing and Tesla is starting to release larger vehicles (Model "X", etc) - yet the standard rate has been dropped from 40 amperes to 32 (I'd say due to too many problems with the standard charging cord at 40 amperes, yet of course they'd never admit it), and the absolute maximum charge rate of 48 amperes on ANY Tesla (excepting the SEMI of course).

****update***** Just checked the Tesla website - apparently they have RERELEASED the 72 ampere charger for the 100 kwh vehicles. Too many must have complained that 48 amperes was simply not enough. I'll have to check if the website was just talking about 'historical' vehicles, or whether the 72 ampere product is now newly available again for new customers.

*****update 2**** On the model X portion, the present limitation is still 48 amperes, so the 'charging portion' must therefore refer to charging those USED model 'x' 's that had a 72 ampere charger. They also claim 200 kw (!!!) at the most modern Superchargers.

Yeah there are now SC's available, yet Mr. Musk has warned owners not to hog the local facilities and to charge at home when possible. I privately think he got some backlash from electric utilities threatening to put Demand Fines on residential Tesla customers since most utilities insist that EV's should use the ENTIRE after midnight period (12- 8am). to recharge - since 40 amps at 8 hours is much easier for them to accomodate than 80 amps at 4 hours (PER CAR), and its not a problem if a neighborhood only has 1 or 2 Teslas, yet a subdivision full of 80 ampere Teslas would cause a UTILITY indigestion as having to provide larger facilities for zero additional revenue over each car being 48 amperes maximum - the present limitation. And of course Tesla has handled the multi-car problem by throttling the HPWC to a premises maximum of 24-80 amperes (user selectable) even if the very large home has up to 4 HPWCs.

But 220 volts is usually generous for most public chargers - they being distant from any electrical services and electricians rarely if ever taking into account pressure drop over long distances from the main buildings, such that some here have said they have charged on as low at 183 volts, it is also true that 195-199 volts isn't uncommon at all.

Now as far as the 3.3 kw GEN 1 LEAF was concerned - a friend would get 18 amperes on a horrible public docking station (184 volts). Since Japan is universally 100/200 volts whether in 50 or 60 HZ areas the GEN 1's EXCELLENT low voltage performance was to be expected. Does anyone know whether the 6.6 kw later chargers would draw an analogous 36 amperes? The largest wall box I have is 32 amperes but I have yet to have someone with a GEN 2 Leaf try it out to see if the charger can hack more than 30.

To clarify, they can all charge at voltages higher than 220V. But they won't charge at 15A or 30A at higher voltages, they will reduce the amps. And yes I believe the LEAF chargers always max at 15A or 30A at lower voltages.

 

[yuhong]

I'd agree, J1772 is the way to go, but try to get them to go 40 or even 48 amps delivered. Many other EV's won't use more than 32, but the Tesla(except SR/SR+) will take 48.

Another rather significant concern in a commercial environment is voltage.... J1772 won't work at 277 volts, which is a typical voltage available from one leg of a 480V three phase supply. The Tesla HPWC will work fine at that voltage, although its officially been removed from the HPWC install manual. We have a J1772 that puts out 32 amps at 183V, which is just plain dismal. I think it was intended to have 208, but is apparently an extremely long run. Even 208 would be mediocre. Try to get the installation reasonably close to 240V, whether via a direct connect to 'official' 240 volts, or via buck transformer(~$300) off the 277V line.

Interestingly, it seems that it is becoming easier to find J1772s at more than 30A. Even ChargePoint is beginning to do them now. The 30A limit dates back to the AVCON days BTW.

 

[Bill25cycle]

To clarify, they can all charge at voltages higher than 220V. But they won't charge at 15A or 30A at higher voltages, they will reduce the amps. And yes I believe the LEAF chargers always max at 15A or 30A at lower voltages.

Not quite... To reiterate, a GEN 1 LEAF will charge at 3.3 kw on the same facility that charges at 2.9 kw on my Cadillac ELR which is expressly limited to 15 amperes.. As I say, my friend with the Leaf got 18 amps on a 183 volt docking station.