EVSE - custom for solar

To start with what is an EVSE?
“Electric Vehicle Supply equipment” also known as the charger.

Why should anyone care about EV’s in ZA?
Well, because of the following combination of factors:
ZA vehicle manufacture contributes around 7% to the GDP.
The domestic market is too small to support this industry without exports.
Export destinations will start banning ICE vehicles imports in 2030.
Ergo, local vehicle manufacture will become EV centric and the government will incentivise, where they presently discouraging sales.

So with that out of the way, I started looking into what’s in the charger.
Well, it turns out not much.
All the fancy bits of the charger are in the car, the charger is basically a switch.

Except really for one clever thing.

Most recent EV’s can take all the current you can throw at them. The thing is your charging point is limited by its own cabling and supply. So it has to tell the car about its limitation so that the charging circuitry is not overloaded.
These AC chargers range from about 7kW to 50kW ( I am leaving out DC chargers deliberately).
How is this achieved?
Well, basically one of the pins in the charging cable carries a PWM signal to the car. And it is that square wave modulation that informs the car how much current to draw.

Well, this leaves a lot of room to play, for example, you plug in a second vehicle into the charging point and the power draw per vehicle can be halved etc.

But I got to thinking about solar charging.

Considering the Victron system: Some people like to keep their batteries charged, some like to use the top 30%, some schedule charging, some people want to divert excess solar power, some people want to limit grid import /export etc. There is a myriad of customisations - all valid.

I think that there is a space here for a manipulated PWM output that reflects a user’s customised charging preferences, a whole lot better than just 7kW or 22kW or 50kW.

I think a DIY solution and a bit of Node-red or something and you could have a car charger that delivers 0 to 50kW and everywhere in between to match your solar production and your own custom requirements. Hell, these days they can even throw the weather forecast into the mix from what I understand.

Well, just spit-balling to hopefully inspire someone to get ahead of the curve … or even Victron?

Edit: I found this, so maybe there is hope:

Edit Edit: But I think it’s not the hardware that is important, it is that PWM signal. As it is a standard protocol any hardware should be able to be manipulated.

Comically dramatic Victron video on that product :slight_smile: (Meat is at 9:30, but the whole thing is cute.)

What is an EVSE?

Also https://www.openevse.com/. EV-OLUTION goes into quite some detail on building an Arduino EVSE.

Some of the larger brand names are also controllable via Modbus as they’re targeted toward grouped installations and have to do power-share in most cases.

Really hoping to see some incentives from gov soon.

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Well, there you go.
It seems a few are already well ahead of the curve. - Good to know that there will probably be a mature product available by the time ZA gets around to needing one.

By the time EV’s hit SA in 2065, the charging “issues” should be resolved :laughing:

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Fast charging from Ford?
This IS a new approach…
I thought that stopping at the roadside for hours is integral to the Ford experience.


Just messing…

Fast charging is key to longer trips, but it seems EV batteries really like sipping power over a long period.

So trickle-charging over a weekend using solar should actually increase the lifetime of the car by quite a bit. If it’s not where you want it to be by 18:00 on Sunday night, the plug-in charger should get it to full by Monday morning.

Obviously you can’t drive it then, which is a bit of a niggle.

First down to Lithium house batteries and then back out seems like quite a waste, but again, sipping power overnight in that case is still good for both batteries.

Edit: I mean “sipping” as non fast-charging. FC is from 50kW to 200kW (and climbing). Typical single phase AC seems to be 32A, so ~ 7kW, but that takes hours, hence “sipping”. There’s also 48A single phase EVSEs, but that only takes you to ~ 10kW. A VW ID.4 has a 50 or 80 kWh battery.

Three phase does that x3, but still far under the slowest fast DC charging. Practically all AC charging should be fine for the car, and not impossible to achieve for the house.

I think the sweet spot will probably be 32A / 7kW power-sharing with the rest of the house. Faster than that in AC will be a very expensive install. For that you can just go to a charging station.

Edit 2: Also, something I didn’t realise earlier: charging slows down dramatically as the battery becomes fuller, so you only really benefit from the very high amps up to something like 80%, but that depends on the vehicle. In the US people seem to only charge for 20m or so, enough to reach the next station on a long trip as it’s more time efficient than full-charging and going further.

I don’t know about trickle charging that seems too much babying.
I think it’s about the same as our solar Lithium batteries.
Keep them between 25-90% SOC and you can charge around 1C ish and expect a long life.
Fast charging won’t do them any favours, but won’t knacker them overnight either.

I believe the same is true for cellphones. I use an old power brick with my new phone so that it doesn’t do “fast charging”. I’m happy with a full battery after two hours instead of < 60 minutes. Makes no difference. I’d rather have the battery usable for longer.

Regarding these EV batteries, they are like 100kWh (some of them), so charging them at 50kW is still only 0.5C… Charging at 5kW is unnecessarily slow.

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That thing is excellent! The last I heard it was going through the big testing rigmarole, making sure it is compliant and all. It will also have VRM integration, so you will see your EV as part of the system.


I’m waiting for Toyota to bring in the RAV4 Prime.

It’s a plug-in Hybrid EV (PHEV) with 60km of electric range and a good old 2.5 liter petrol engine. That means I can do all the in-town driving on electric power, and if I need to go outside of town I just start the engine.

Also, 0-100km/h in like 6 seconds. It has three electrical motors, two driving the front wheels with the engine (like a Prius), and a third one for the rear axle, turning it into an AWD vehicle.

The first models would likely be almost unaffordable for a cheapskate* like me (when it comes to cars anyway), I expect them to be around 650k BEFORE the government adds their extra taxes, but maybe a good 2- or 3-year old will fall into my range at some point.

* On being a cheapskate when it comes to cars. Cars are not investments. If they weren’t also fashion accessories and essential appliances, they’d be nothing else than a grudge expense. These days you are (apparently?) expected to sink half a million small antelopes into a good SUV (that can at least climb the curb at the local school where the mommies are clogging up the place with their Toyota Fortuners), but I try to resist this like someone who learned that the price of diamonds are manipulated through artificial scarcity… and instead bought his wife something else… (true story).

Cars are not investments. They devalue. They hog good capital that could have been elsewhere (making money). They have to be insured, they eat up tires, the other idi… I mean shoppers scratch up your paintwork… etc etc. Lastly, by far the lowest cost item of owning a car (for me), there is the fuel and service costs. So anybody trying to sell me an electric car based on the running cost is going to lose the battle really quickly… cause that is not where the real money is lost.

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I’ve been watching these options now for a number of years, they used to have a conversion kit for a Tazz.


Found this in SA now:

More info:

Nothing beats the sound of an original Isuzu diesel right, so I’ve been looking around a bit over the last ±10 years to add some EV parts to her wisely in order to make an ROI on the shart distance drives ito diesel and maintenance when driving in town, keeping the 2.8l turbo diesel engine right where it is because it has more than enough spare to recharge batteries when driving. My version of diesel electric.

Before the batteries have been the troublesome part when I started looking at this, 8 of 16 x T105’s not a chance no(!) followed by lithiums costing a small fortune, and still very small, now we have like the new 280ah cells, with 16 of them like 100kg’s.

I’m patiently waiting for local engineering shops to jump on this bandwagon to help figure out how to make it so, it becomes as common as replacing a gearbox/engine/diff.

Because Suzi stands a lot, the cells can be the “2nd battery bank parked in the garage”. Unplug it and drive locally, come back and charge using solar, cause in case of urgency, the diesel engine is silently waiting.

To have a greener earth, there is a case to be made for re-using/re-purposing that what has already cost in Co2 than to expend more Co2 to manufacture new.

I still think hybrids are the worst of both worlds. You go full petrol or full electric. No point in carrying both.

It is interesting how much people are willing to spend on “investments” into their lifestyle/mental health/recreation. I know of quite a number of cyclists who has spend more on their bikes, races, and everything that goes along with it, than we spent on our family vehicle - and we didn’t buy a particularly cheap vehicle either.

While cars aren’t monetary investments (will make your money worth more tomorrow than it was yesterday), people also seem to want to, at least eventually, spend their money on leisure, which is different for everybody - You actually need very little to survive. So I guess the question becomes: When your monetary investments mature, what do you want to do with that money? If you have to spend it purely on survival, that is one thing. If you want to spend it on trips overseas, eating out at nice restaurants, buy a nice car, buy some cool gadgets, well… Even “spending” it on retiring earlier is leisure as your biggest asset, your ability to earn income, you want to “cash out”.

The more conservative approach would be to want to build wealth for future generations. Regardless, then you are just passing the buck to the next generation as they would eventually use it for some non-monetary investment.

Buying Hybrids new, I feel the same.

But, we need answers for:

The 1st problem: SA has distances to travel at times that ICE engines can handle with ease because of petrol stations being close to each other.

The 2nd problem comes from the short distances driven in cities, work/shops//braais that are causing the most pollution in cities, as public transport is not as good nor reliable as what is needed for reducing 1st world cities fumes.

The 3rd problem is to justify spending half a bar or more on a vehicle to drive “short distances” in town when we are most definitely going to drive the long distances too.

EV’s cannot do that today, nor is there an answer coming soon to a charging station near where you want to go and drive all over SA, and that causes the hibbies with people wanting to buy EV’s

We need, for the foreseeable future, an answer for both, city driving and long-distance, that does not cost half a bar or more.

Hence me leaning towards add-on kits to existing vehicles for city driving to “extend” their lifetime and reduce our Co2 footprint in cities, for now.

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For me, anything more than 3 hours travel time, I fly.
Time to too short to sit in cars. For most people, 99% of their travel time in cars is short trips. No point in buying a car to cover that missing 1%

There is also an international trend to hire a vehicle for longer trips. The EV being the daily commute and go to the shops type vehicle.
@TheTerribleTriplet has got a point about the price though, but like everything the Chinese have a solution:
The “Wuling Mini EV” is outselling Tesla at sub $7K.
Not a car for the drag racing, status sharing, girlfriend impressing teenager, but I’d buy one.

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Yes, maybe. But here is my conundrum…

Not just SA. I have a big love for a place North of here…

Sure… if there is an airport anywhere near to where you are going. Also, Hosea Kutako is an insanely expensive airport to land on, and with the pandemic and all that, practically nobody flies there anymore. Airlink has two flights a week (I think)… from OR Tambo. An I can drive there with the whole family for a third of the cost… and have my own car for the week (no rental required).

So I have this unique situation where I want an EV… but range is not my problem. The range I require is so far outside the present capabilities of an EV that it doesn’t even matter. I’m going to need two cars for many years to come… an ICE-vehicle for the longer distances, an electric for the shorter distances.

Also, because the longer distances tend to double as holidays, that car is going to be the nicer one.

And I’m not spending >500k on the second car in the household. I refuse.

But… if I can get ONE car that can do both, I’ll lug the petrol engine along, I’m fine with that. Yeah, it is suboptimal, but it fixes the unique problem I have.

Indeed… which is why I will spend SOME money on a car… and I will probably even spend more than I should on a really nice one. But I have what one might call “psychological limits”. I cannot imagine that someone would spend 1.2 million on a Jaguar F-type or 1.8 million on a Mercedes Benz CLA (let alone gift it to someone), when you can get the job done for less than half that.

Yeah sure, it is nicer… but is it a million rand more nicer?

I totally understand the lifestyle/recreation argument, even the fashion argument. I find it really really hard to buy a cheap car with plastic wheel covers on steelies. I will spend money to get the model with alloys. So despite my righteous indignation on the topic of cars not being investments… I do spend more on cars then I need to already. Which is sort of the point. I don’t need this to get any worse :slight_smile:

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When the i3 launched in the states the dealer would allow you to take an X5 for longer trips if you were taking a long drive for a weekend away. I can’t remember what it worked out too but you got I think 2 weeks of free X5 use, after that you paid a nominal fee to use the bigger car when you needed it.