Would this work? Solar/wind to UPS, UPS to PHEV ?

Just thinking of some way to solar charge my PHEV without breaking the bank. This seems silly, but stay with me guys..

So, let's say that, with my very limited knowledge in electricity, I figure out a way to charge a UPS's battery with, say, a solar panel wired directly to the battery poles. Apart of the UPS's computer detecting voltage fluctuations from the electricity source, it shouldn't complain too much, and even simply stay off until the current of the battery attains a specific charge level.

Then, let's say I plug my PHEV's supplied charging brick to the UPS's 110v outlet. oh and let's add a timer device (like the ones for holliday lights or for pool motors) to give a chance to the UPS to charge more than the minimum.

In theory, that should work, right? I mean, the UPS might be off more often than on, but the UPS would give "clean" sine energy to the PHEV?

What would be the limitations in this setup? Other than a very very lenghty charge time that could span over days, rather than hours ?

philwire said:

Just thinking of some way to solar charge my PHEV without breaking the bank. This seems silly, but stay with me guys..

So, let's say that, with my very limited knowledge in electricity, I figure out a way to charge a UPS's battery with, say, a solar panel wired directly to the battery poles. Apart of the UPS's computer detecting voltage fluctuations from the electricity source, it shouldn't complain too much, and even simply stay off until the current of the battery attains a specific charge level.

Then, let's say I plug my PHEV's supplied charging brick to the UPS's 110v outlet. oh and let's add a timer device (like the ones for holliday lights or for pool motors) to give a chance to the UPS to charge more than the minimum.

In theory, that should work, right? I mean, the UPS might be off more often than on, but the UPS would give "clean" sine energy to the PHEV?

What would be the limitations in this setup? Other than a very very lenghty charge time that could span over days, rather than hours ?

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The main limitation would be that it wouldn't work....

Why is that, HHL?

I dont see any reason that wont work, if he gets a big enough UPS, say 2300w
It would be able to charge the car, for a while.

Most of the ones ive seen outputs clean sinus power.

Charging the 12v internal batterys isnt a big deal.

Efficient? Maybe not, but it would work IMO

No. You'd wreck the UPS.
Your charger requires over 2kW and well beyond what a UPS is likely to cope with.
The capacity of the battery store will be insufficient to satisfy that of the PHEV.

RoyM said:

Why is that, HHL?

I dont see any reason that wont work, if he gets a big enough UPS, say 2300w
It would be able to charge the car, for a while.

Most of the ones ive seen outputs clean sinus power.

Charging the 12v internal batterys isnt a big deal.

Efficient? Maybe not, but it would work IMO

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I agree with RoyM. The good quality UPSs (or even 12v inverters) I use at work are sine wave for use with computers. Access to a good earth for the evse may be required from memory.

Big, expensive UPSs are available to shorten the time for charging.

Charging down to 6 amps ie approx 1.44 kW is available with some evses.

I can see no reason why this wouldn’t work, it would just be expensive. The lowest charge rate the evse can advertise to the cars onboard charger is 6A, this I think is regardless of voltage. So 6A at 110V is 660W which wouldn’t require much of a UPS?
You would need a lot of batteries, a good UPS and an EVSE which you can set to 6A, not going to be cheap.

Craigy said:

You would need a lot of batteries, a good UPS and an EVSE which you can set to 6A, not going to be cheap.

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Instead of a lot of batteries the OP was going to solar panels I think.

Craigy said:

I can see no reason why this wouldn’t work, it would just be expensive. The lowest charge rate the evse can advertise to the cars onboard charger is 6A, this I think is regardless of voltage. So 6A at 110V is 660W which wouldn’t require much of a UPS?

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Hell at 660w it would only require at least 15 hrs or more with cell balancing I think to charge a newish PHEV battery. :lol: That is a long solar day.

Edit surely the OP would be hooking up more than one, common size, solar panel to make this discussion feasible ie and not require heaps of batteries and loooooooooooong time to charge.

Yes, it “could” work but I don’t think it would be cheap to do or very effective.
I’d not noticed the 110V supply and had also overlooked the possibility of a 6A charger. That solution would take a long time to charge the PHEV, though, you still need around 10kWh to refill the PHEV from empty.
You’d need more than 660W of panels to overcome inefficiencies and a poor solar harvest (cloud or angle of incidence). The battery capacity of the UPS may not matter if charging was only performed whilst the solar gain was large enough to satisfy demand but that would depend on location and time of year. You rarely get “full sun” and cannot expect significant solar gain in Northern regions during Winter.

Sounds like OP would get a cheaper and better system by simply buying an on-grid solar system, then you can obviously just plug the car to any outlet in the house..

twosout said:

Yes, it “could” work but I don’t think it would be cheap to do or very effective.
....

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I did analyzed this option time ago

Charge from solar panels directly, implies to have the car at home during the day, something that in my case is not really possible
As well, the solar system should be over dimension, since clouds and rain can drop the solar power by a factor of 5 and even 10.

Using batteries, it will allow to collect and use 100% of solar energy .. but battery are expensive and have limited life (as we can see in the SOH of our PHEV)

At the end ... I did not find economical convenient to bother to make such installation.

I think in most of the countries is more convenient to avoid the battery storage and use the solar energy for home usage and eventually sell the excess energy to the electric network.

Hi all, thanks for your input, it's very constructive.

What I meant when I started the post was disregarding the source itself. I meant solar or wind, but could also be handcrank, pedal, watermill, steam, nuclear, enslaved smurfs, whatever's off the usual grid. For example, in winter around here in Quebec, Canada, the very flat field behind my house generates some pretty violent and powerful winds that are just waiting for someone to grab their energy and store them in a battery IMO.

I meant the UPS in the equation because AFAIK the PHEV's onboard battery and charger won't appreciate such variable and unstable fluctuations as solar or wind, so the UPS would store the energy temporarily enough to generate the PHEV for a small cycle, a little like plugging my PHEV for 5 minutes and unplugging it because I forgot to buy some milk. Then I come back, plug back my PHEV for 5 minutes and unplug it because a tennager needs a ride home. ad infinitum for the evening sometimes for an infinite number of reasons In both scenarios, the chemicals in the battery can't do much in 5 minutes because they seem to need more time to settle down from "dispensing" mode and get into "storing" mode.

Maybe a UPS is not a convenient power storage option? Should the energy source crank some weight up some string and, when released, a dynamo linked to a pulley from the weight charge the PHEV? I don't know, that's the fun and creative side of the discussion

Look, it is possible, but I don't think you've considered just how expensive this would be.

I have a 1.5 kW solar system, it generates about 5kWh per day on average, (I'm in a part of Australia that is ideal for PV solar).

I need about 10 kWh every two days to keep my PHEV charged, with my duty cycle.

So I'm considering a 10kWh battery.

Currently, my State Government is subsidising (some) battery purchases to bring the price of the battery down to $500 per kWh.

Lets add up some prices:

1.5 kW solar system, including inverter: $3000 (with a hefty government subsidy)
10 kWh battery $5000 (with a hefty government subsidy)

Don't forget that batteries have a limited number of charges and discharges.

The last time I priced a 10 kWh battery (with controller and battery management software, both of which are vital) the prices was $30,000. So prices have come down.

Most UPS units are just the equivalent of a couple of motorbike batteries in a box with a controller.

Absolutely not up to the job of charging a PHEV. The first time you used it, you'd probably have to throw the batteries away.

Think of it this way... Can you use three batteries to charge up the 100 batteries in your car? No.