Can 3.3kw charger be upgraded to 6.6kw on Prius Prime or RAV4 Prime?

The Rav4 Prime has 17 more miles of EV range than the Prius Prime. You wouldn't need a charge at Target.

With hypothetical cars where the only difference is efficiency, yes, the faster charger in the efficient one has benefits. I wasn't deny there were. I was denying they were of no benefit to the less efficient car. The faster charger lets the less efficient one charge up in the same amount of time as the other. Many public chargers bill by time, with the faster charger, the less efficient car isn't paying more per mile than the efficient one.

Of course, the faster charger would still benefit the efficient car, but these design decisions aren't made in a vacuum, and the actual models we are discussing have far more differences between them. The Prius battery is less than half the capacity of the Rav4's. Charging it up at Level 1 takes 5 to 6 hours; practically the same as the Rav4's Level 2 rate with the 3.3kW charger in regards to home charging. The Prius Level 2 is a little faster than the Rav4's with 6.6kW charger. The faster charger does have a higher cost, which will stand out more on the Prius $11,000 lower starting price.

For markets with cheap fuel, the faster charger is of little value for the cost on the Prius. In markets where gas isn't cheap and/or limited home charging, Toyota gave the Prius CHAdeMO. The cost of this is likely lower than the additional cost for the faster charger. It is also faster; 20 minutes to reach 80% charge.

Of course, that 20 minutes is under optima conditions, like your example. The realities of charging a small, air cooled battery that is already warm from use means the charge time will be longer. The Rav4, with larger battery with chilled air cooling, will make more efficient use of faster charging.

 

So that's even less reason to need the faster charger on the RAV4, in my opinion. I could use a few miles quickly everyday with the Prius, but I only drive over 40 miles a day about once a week or less.

 

In this illustration (ignore the numbers shown), if the top string represents the type of a Prius Prime pack, then the bottom pair of strings would represent the RAV4 Prime type.


This would allow both cars to use the same individual cells models, but with different numbers of them wired differently. 1x95 for the Prius, 2x96 for the Rav4.

Beware that I don't know this to be what Toyota actually did, until I can track down whatever article gave me that impression.

 

It isn’t. New Car Features (more info) for RAV4 Prime vehicles describes the HV battery, 96 cells in series:

(c) The 24 lithium-ion battery cells provided for each HV battery stack are connected in series in a bus bar module.

(d) The HV battery consists of 4 HV battery stacks. They are connected to each other in series through bus bar modules and wiring harness.​

One major new development for the HV battery is the refrigerant cooling system:

(1) A refrigerant cooling system is used which cools the HV battery using the refrigerant of the air conditioning system.

(2) This system cools the HV battery by making the No. 1 traction battery cooler conductor, through which low temperature refrigerant passes, touch the bottom of the HV battery via the No. 1 traction battery cooler sheet.​

New Car Features also has illustrations of the 3.3 kW type and 6.6 kW type electric vehicle charger assemblies. There are physical differences between the two types—such as different locations for the cooling blower—but it’s not clear whether the mounting points are the same. The size, arrangement, and electrical connectors are definitely not the same as those of the charger assemblies used on Prius Prime cars.

The Repair Manual mentions another difference between the RAV4 Prime models with 3.3 kW and 6.6 kW charger assemblies: only those with the latter have thermistors in the inlet AC charger cable (i.e., charging socket). See the information for DTCs P0D9911, P0D9915, P0EE711, and P0EE715.

 

All the comments in this thread do not consider the Rav4 Prime cells are prismatic, not cylindrical, and the resulting differences in performance. The liquid cooling is needed not solely because of the number of cells, but the shape.

 

But you are an individual. The design decisions for cars are made for the group of buyers. The 6.6kW is an option for the Rav4 because it has a bigger battery with better cooling to handle the faster rate. The speed increase for the Prius will not cut the charge time by 50%; it might only get it to a 25% reduction.

IMO, no PHEV with less than 50 miles of EV range needs faster than 3.3kW in the US. Level 2 with that will charge the car before 8 hours at home with that. If you want more EV miles, get a PHEV or BEV with longer range.

Does it directly cool the battery, or is cooling incoming air. The Outlander PHEV does the latter.

 

Thanks for that detail and link. That explains why I couldn't track down the source of my impression to a contrary configuration. Maybe it was another senior moment.

If it had been configured as I thought, it would have been two (or more) strings of 96 cells per string. I.e. 192 total cells, or even some higher multiple of 96​

 

Correct; the HV battery cooling is by direct conduction, not by air flow.

 

or DC conversion...

 

An upgrade from 3.3kW to 6.6kW for AC charging would have quite a few advantages, in some regions more than others of course. I already have CHAdeMO in my 2018 Prius PHEV (Japanese-import) but I'm still interested, depending on technical feasibility and on price. Some (=many?) would ask "why consider this at all?".

Background

• CHAdeMO charges the useful capacity of my battery from 0% to 80% in 16min. This corresponds to about 17kW and a charging current of about 70Amps. (The rechargeable battery capacity for me is ave. 6.0kWh).
• The installed 3.3kW AC charger charges from 0% to 100% in just about 2 hours.
  The max.current I've seen has been 13.6Amps.
• Normally, I commute using only EV mode i.e. no ICE use and charge at home on cheap night-time rates at 1.8kW i.e. 240V/7.7Amps, which takes approx. 3hours 15min.

So for normal everyday use the present equipment is fine i.e. no change necessary.

On longer distance drives and road-trips, however, things look different. The ICE is great but (where I live) using ICE costs 2 to 3 times more per km than using EV when charging on full domestic electricity rates. The difference is actually much more at home due to discounts or availability of free electricity e.g. I currently get 3 hours of free power per night.

Away from home electricity costs more but there are a lot of free J-1772 and Type 2 stations available, which reduces fuel costs on EV. Waiting for a 3.3kW full charge is, however, really far too long to wait. CHAdeMO is great BUT much more expensive at the (here rather exorbitant) rates charged. A 6.6kW charger (or greater) would have some definite advantages but few disadvantages:

Advantages
1. AC charging can charge the battery to 100% while CHAdeMO/CCS-SAE only charge to 80% - so you get 25% more km on EV.

2. There are already many more J-1772 and Type 2 available than CHAdeMO, CCS-SAE, and Tesla chargers combined (and likely to remain so).

3. Installation and maintenance of charging points is much cheaper for AC than DC, so AC charging points will remain more plentiful and will more frequently provide free/low-cost electricity. So retailers, employers, public services, etc. can afford AC points. So non-domestic charging points will remain more plentiful and more often be free-of-charge.

3. Home charging at 7.7kW is only 32Amps at 240V (even slightly higher currents are often not problematic domestically) so you can install one at home.

4. Where I live, the Type 2 points are often available immediately but the CHAdeMO and CCS-SAE chargers are often in use or even have a queue (... it's great to have an ICE waiting for use ...)

5. Where I live, EV driving is much cheaper than ICE driving - especially if free charging is available at sites useful for your trip.

Disadvantages (for an upgrade from 3.3kW)
6. Technical feasibility of upgrading e.g. compatibility and heat build-up (it's under the back seat, I believe).
7. Cost of upgrading.

Charging Time
Charging from 0% to 80% with CHAdeMO/CCS-SAE at about 17kW/70Amps takes me 16min. This same amount of energy (i.e. to 80%) at 6.6kW/27Amps would take about 42min. (If 7.7kW or 10kW is possible then times would be 35min or 27min respectively.) The option to charge to 100% is an added bonus.

(Slightly) longer charging times has some advantages on longer trips:
8. A drinks and toilet break can easily take longer than 16min.
9. Eating lunch always takes me/us more than 16min.
10. Heat build-up and other stresses for the battery are much less at lower charge rates

Conclusion
So, I'm not advocating for road-trips predominantly on EV for our Prius PHEV/Prime, and I would continue to use the ICE engine for mountain driving and extended periods of higher-speed travel. However, there are arguments for an upgraded AC charging system for away-from-home travel. Any extra km on EV is much cheaper, can reduce ICE use and fuel (... maintenance ...), and even be better for the climate (... my little contribution). It all depends on cost and do-ability.

 

Add to the pros for the upgrade is if you use chargers with fees by the minute. A 3.3kW charger means you are being overcharged.

Curious that the CHAdeMO stops at 80% on a Prius Prime. Other plug ins don't stop, but greatly slow down to avoid overheating. In terms of travel time, it is faster to stop at that 80%, and continue to the next charger.

With the Rav4P, the chargers could very well be plug and play. In the US, the onboard charger will cost about $1800(MSRP is over $2200). Without a factory 6.6kW option for the Prius PHV, it gets trickier to upgrade, which usually means more expensive. I don't think a Rav4 3.3kW would work in the Prius, as both Rav4 chargers have ducted fans to them for cooling. The cooling will likely be an issue in the Prius if keeping it in the same location. On the new PHV, Toyota placed the 3.5kW charger in the cargo area, and it has a very large heatsink.

 

Agreed, per minute costs in addition to cost/kWh make charging at 3.3kW pretty much always uneconomic compared to using the ICE. These combined with the time required pretty much exclude charging at 3.3kW as an alternative to CHAdeMO/CCS-SAE.

Perhaps installing a second 3.3kW in parallel to the existing 3.3kW AC charger is possible? Maybe this second charger could be made "invisible" to the car while still being controlled by the existing system e.g. for throttling in case of heat build-up and to prevent over-charging? The second 3.3kW charger could be mounted elsewhere i.e. maybe not with the existing 3.3kW charger under the back seat. The combined 6.6kW/27Amp is much less than CHAdeMO's equiv.17kW/70Amp, so heating and over-stressing of the battery shouldn't be an issue.

[Edit]
CHAdeMO (and CCS-SAE) stop at 80% to protect the battery. Many EV charging systems do indeed reduce the charge rate instead of stopping completely at 80% these days, but not our Prius PHEV (which is also stated in the handbook).

 

Intelligent battery chargers taper off their charge rate as the battery approaches full. Having two chargers in parallel may work fine during the initial bulk charging stage, but it seems like the later taper charging stage could easily get messed up if the chargers were not very specifically designed to work in parallel.

 

If finishing charging when close to full is a problem, perhaps the second charger needs a cut-off switch at perhaps 95% charge, or at a suitable voltage/temperature combination, or perhaps when the current drops below a suitable value? This would leave the existing 3.3kW charger to finish off charging.

 

I had read, this was a thing on all PHEVs from Toyota, particularly the new vehicles. My thoughts went two ways, one... make my 2013 PIP and 2017 Prime CHAdeMO by adding on the parts that are different between non CHAdeMO charging Toyota PHEV and the CHAdeMO Toyota PHEV. I now have a source for the parts, still waiting to see a package where its one of the new Lithium batteries from Toyo/Lex thats smaller and more powerful and the CHAdeMO parts. They once had Japan spec PRIME HV battery and other components not relating the CHAdeMO for sale in a kit.

We cant use the Rav4 Prime batteries as the composition is different in the Prius, I'm just going with the thought even its charger might only work for the battery composition in the vehicle. But... RX PHEV! or what I've been on the hunt for the 71.4-72.8 kWh in the new bz4x as it'll work and it's the latest and greatest battery until the new 18.1kWh battery in the RX is released. Now the AWD bz4x is the one that has the batter that will work, then my thoughts go to the ideal setup. CHAdeMO charging speeds with a higher capacity battery should put me at well over 1,000 miles per gas tank full up.

That all to say, IMO in a stock battery having PIP or Prime, the 4.4 kWh and 8.8 kWh batteries make no sense to CHAdeMO

Wait, I thought CHAdeMO was 80kW/264Amp

 

CHAedeMO's first standard was 62.5 kW (125 A × 500 V DC). https://en.wikipedia.org/wiki/CHAdeMO
There is a faster one, but the chargers and cars don't have to take full advantage of the standard. Many chargers in the US were set to 50kW or less for reduced costs to the operator, and the configuration of the battery puts limits on how fast it can charge.

Fast DC charging on a Prius plug in doesn't make sense in the US as gas is cheap, many can charge at home, and Level 2 charging isn't difficult to set up if it isn't already available. That isn't the case in Japan. Plus, they have CHAdeMO power stations available that will let your car power your house there. They had considered having that available for the Mirai here.

 

I say its because the little 4.4kWh battery is too small, now.. having an 18.1kWh battery, yes then it makes perfect sense. The thought is if a Prime had a 18.1kWh battery and could charge in less than an hour, it should get at least 60miles on a full charge. This IMO is when its worth it.