quick question here : where can i find technical details about the Prime charging system ? Someone is trying to make me believe that there is no balancing cells cycle when using the 110V charger and can only be done when using a 240V charging station ... I tried to tell him that 110V or 240V , the cells are balanced at some point during the charging session ( if not interrupted ) .. it's kind of mandatory. I told him also that it's a argument that a '' shady '' vendor use to sell you a 240V charging station when you don't really need it .. any thoughts on this?
Weber Auto has some good videos that explain various features of the charge system: WeberAuto - YouTube
I don’t know anything about the charging system internals but it seems unlikely. The AC from the wall is converted to DC and stepped up to the battery voltage (regardless of input voltage). Also, they allow you to charge the car off 110V only. For customers who do that, I can’t see Toyota being ok with never balancing batteries. They would need to pay for tons of warranty repairs.
You are correct that the Prius charge/balance cycle is independent of the power source as is true in any other vehicle. And the top-end balancing performs at the same speed on L1 and L2 (and L3) since there is very little power being drawn, it is just time intensive. I would also agree with the cynical statement that it was a shady sales tactic to sell them an L2 charger and probably got a kickback from a local electrician friend too.
To balance the cells, you need to get them all up to 100% state of charge. The in-car charger shuts of at about 80% SOC, so there is no balancing of cells at either wall voltage without special equipment. AFAIK, there is still no such equipment for the Prime or the PiP.
More than you ever wanted to know about the Prime batteries. There is a Gen 2 high voltage system video which should have the ideas right, but the details wrong (by Gen 4 the A/C compressor is powered by the high voltage battery, not 201 volts AC) This is a video for a Gen 4 inverter, but it is a tear down, not functional theory.
Am I supposed to know what anyone on this thread is talking about? If I’m charging with one of Rob43’s conversion pigtails at 240 is that better than charging at 110? Are you not supposed to interrupt a charging session while on 240?
Jeff Hicks at these Amperages, there is no 'best'; just length of time it takes to charge. There are DC fast chargers (for other cars) that potentially charge too fast, typically they solve this by only charging to 80%. If you charge in half the time, the odds of your session being interrupted go down. So you can worry about it less. The upside is that the adapter charges in close to half the time; the downsides are cost, some safety if you don't read the warning, and the availability of a compatible 240 volt outlet where you need one. 240 volts outlets vary a lot in North America.
Here is North America 240 volts is rare and 'industrial', we forget that every plug in Europe is 230 volts and they do fine. The manufacturers all have experience in Europe. It is hard to bring to America because 'plugs'. Look at this mess: And then there are 'locking' outlets!
Would charging at 110 volts better for the pack, vs 240? I seem to recall on-the-road high-speed chargers were rough on the pack? Or is 110 vs 240 difference trivial?
It's trivial. Even at 240 volts, it's nowhere near the rate of power transfer that happens just when driving normally. Think about how long it takes to charge vs how long it takes to discharge if you just drive at a steady 60 mph. It would discharge in about a half hour or so, but it would take about two hours to charge back up.
And: When driving down a long steep hill or mountain, the Primes DC charging quickly re-charges the battery pack....Much Much faster than any 240v EVSE can. (Over the same time in seconds) Rob43
Here's detail showing Charge-Mode delivers electricity to the battery-pack at double the rate as through a 240-volt connection...
Yes, high speed chargers can be hard on packs under certain circumstances.. That is what charging programs in the cars are for, to reduce that stress whenever the pack is out of it's optimal charging state. ie: too hot or too cold and out of balance cells in the pack that cause heat to build up in the weaker faster charging/discharging cells. Yes, normally, charging at 240 volts is trivial in relation to charging at 120 volts. But there are times when it is not trivial. During those times when charging is not optimal in the Prime the charging program will reduce the rate of charge per the circumstances the sensors present to the program, without informing the driver of any differences. Think Prime preconditioning with both heat or A/C, pack heaters when ambient temps fall. dynamic grille block, heat pump and the 10% unused voltage at the pack top and bottom of total pack capacity. All of the Prime accessories mentioned above are in part to help keep the pack from being stressed under sub optimal charging conditions. The 8 Amp / Max Charging switch available in the Pimes MID under the Maintenance sub section is written up in the owners manual as being available to reduce charging at both 120 volts and 240 volts to almost half speed to reduce the Amperes drawn from the Electrical Supply in case the Max setting draws too much and blows a fuse of trips a breaker. But as our packs age it will also come in handy as one tool we can use to help balance cells in the pack. It will only be a stop gap tool, but a tool none the less.
Just a small nit to pick: My understanding is that the Prime has an 8.8kWh battery, but when driving from 100% to 0% as displayed on the dash I am only able to use 6.0 kWh. That means there's really about 16% at the top and bottom "unused."
Others have calculated kWh in at 6.3 to 6.6 and kWh at the wheels at around 5.5 which is the number I use and agree with. I take miles driven and divide by kWh/mile and it usually comes pretty close to 5.5 kWh If you use a scangauge2, hybrid assistant, dr prius or torque, I believe all of them will show SOC at 83 - 84% top and something like 8 - 10% bottom, but bottom is a bit more subjective, depending on just how low any one driver can get it down to before the ICE fires up. Hey, I take a lot of what other say here at their word, cause I just don't have the time to cover everything the car has and my mafhs not the best either, especially when using symbols I haven't seen before.