Charging the Prime

The only reason not to use max is if you need to share the circuit with something demanding.

I used max for charging on a line with our freezer. It worked fine.

 

It just depends on your house wiring. I use 120vac for charging our Prius. I have 240vac available, but since our household power is from a solar system, I am concerned about such a huge load.

 

On a 240VAC, L2 EVSE, the Prime will draw a maximum of 16A. However, you can configure most EVSE to limit the current to a current level safe for your solar power system. But if there is no requirement to charge faster, an ordinary 12A 120VAC will do fine.

Bob Wilson

 

Where can we set the amps when charging at 120V? Mine keeps tripping my GFCI, so if I can lower the amps that would be awesome.

 

You can try doing it here:

 

A GFCI can also trip if there is a grounding/circuit problem.

Bob Wilson

 

Thanks PfD. Vehicle settings was the one place I didn't look. lol

I have a GFCI power strip that is rated, supposedly at 13amps, but it still trips even when I set the charge to 8. But have no issues when I plug directly into the wall. Oh well, I'll set it back to Max and just plug it into the wall.

 

Wondering if 8 amps, which I purposely set, will produce a "cooler" charging experience overnight and less energy loss, and better EV mileage, I am at 35.8 miles, which continues to improve since I bought the car in late March.

 

No.

The Prime has three charging rates:

240V 16A - slow
120V 12A - very slow
120V 8A - super slow

None are particularly relevant for battery heating or battery charge efficiency.

 

Having a Leviton 240v dedicated 16amp unit for our 2012 PIP with a 4.4 battery pack, which only gets about 12 EV miles (wife doesn't care), from what I have read and experienced, ambient temperature, heat loss and battery charge is an issue, understanding energy efficiency. So the idea of a slow cool 8amp charge overnight may in fact have some residual value, without any accurate testing. I will continue to monitor our current Prime 35.8 EV range.

 

I regularly charge batteries similar to the Prime's batteries at a rate equivalent to a full charge in 20 minutes without them getting more than a couple of degrees above ambient, with no cooling. Charging in 2 hours is such a slow rate that battery heating from the charge is close enough to zero that it can be safely ignored.

 

How long does it take to charge on each of these three?

 

Amps vary at each voltage, so it's not just a simple number.

On the ChargePoint station at work, I get a rate of 3.1 kW. At home on my Juice Box, I get 3.6 kW. Both are 240 volts.

The more kW, the faster. At home, it's exactly 2 hours. At work, I don't care... since there is never any rush and the pack isn't usually depleted entirely.

 

Full charge @ 120V 12A is ~5.5 hours
Full charge @ 240 V is ~2.5 hours
I haven't tried the 8A limited 120V charge yet.

 

I would be interested in how long it takes on 8A 120V charge... so here's the thing, wouldn't the 8A charging be "easier going" on the battery and thus make the battery last longer over years of use? This is one of the reasons when you "quick-charge" a smartphone where 80% of the battery can be recharged in 30 mins, all the articles say that you should not use that too much as it "stresses out" the battery and it's always best to charge on a lower amperage (like 1A 5v USB) than some of these faster options... could that be the case here in that if you're leaving it overnight anyway, would it not make sense to lower the amperage to go "easier" on the battery and thus prolong its life?

 

No.

Remember, the fastest charge rate at 240V is about equivalent to a 3 hour smartphone battery charge (25-85 in 2 hours versus 0-100 in 3 hours). There's no appreciable difference between a 3 hour charge, a 6 hour charge and an 8 hour charge as far as batter longevity goes. They're all really slow.

 

GE durastation 240v downrated to 16a 0 to 100% in 1h50min