Minimum Amps to charge HV Battery

Anything is better than nothing so, yes, you can charge at either of these amperages but it will take a long time to see any noticeable effects.

That said, a Prius parked with out the lights on draws about 1 or 2 amps alone.
So if you never plan on putting more than 2.5 amps in, you are barely keeping up with the accessories.

 

First, Eric this is the HV battery which is totally disconnected when a Prius is off, not the accessory battery.

My ScanGauge tells me that 2.5 to 5 amps is a low current compared to that normal draw/incoming current. The charging system needs to track State Of Charge (SOC) and not try to go above 80% or the Prius will waste the extra energy. You should also track battery temperature and limit charging when the temperature gets much above 110 Degrees F. Both parameters can be read on the CAN bus (OBD2) since my ScanGauge can read them via xGauges.

JeffD

 

5 amps is not nearly enough to make a meaningful difference in fuel economy. If you are planning to DIY, consider following pEEf's example:

http://priuschat.com/forums/gen-ii-...-plug-in-hybrid-electric-vehicle-project.html

 

What matters is watt-hours (or amp-hours) rather than amps. So how long are you going to be charging between uses? The nominal rating for the battery is 6.5 Amp-hours (source: [ame=http://en.wikipedia.org/wiki/Toyota_Prius]Toyota Prius - Wikipedia, the free encyclopedia[/ame] )

That is 1-2 amps at 12volts not 1-2 amps at 270v.

To be clear you (OP) are talking about Volts DC, and are sure of the charging voltage necessary for your model, correct?

 

2 amps at 12 volts isn't enough for a single headlight, let alone all the other lights and the ECUs.

 

On my system the Enginer converter seems to know when to charge and when not to charge. For example, after driving I would leave the car on for about 5-10 minutes for the HV battery to be charged up for the next drive. The converter would put out 14-15 amps until it reaches 245v. Once it reached 245v the amperage throttles back to 8.5 amps for 20-30 seconds. Afterwards it throttles back both voltage and amperage to 235V 2.35A. 2.85a if I have the AC on. It stays there until I turn off the car. While driving, the converter puts out 14-20 amps 220-240v. The only time it shows 0Ao is when braking.

Kammsss, you have a Gen II so you have more choices than us Gen III folks. Judging from your previous experience with PHEV, I'd assume that you want a plug and play system this time around and new Enginer system is out of the question. That leaves either Hymotion, Plugin Supply or Plug-In Conversion Corporation. All 3 systems cost over $10K. In CA, there are no state incentive for converting your Prius like Colorado. The best you can do is federal rebate of 10%. Hymotion has been crash tested so it's the safest in terms of physical placement in the car. PICC kit costs about $13000 installed. It replaces your factory NiMH with a 10KW NiMH. It's capable of regen into the PHEV battery pack and allows EV speed of up to 70mph. PIS adds 10KW of LiFePo4 and also allows regen into the PHEV pack and also allows EV speed of up to 70MPH. I think the price is also $13000 installed. Both systems offer 50 miles EV range in the city and 30 miles on the freeway. PIS also offers a 4KW system that also capable of regen braking, 70MPH EV and spare tire access for almost half the price. You should get in touch with kiettyyyy He's based in Los Angeles too. Check out his thread http://priuschat.com/forums/prius-p...88262-2011-plug-in-supply-product-teaser.html

 

If it drew 2 amps it would kill the 12V battery in under 24 hours, in under 48 hours at one amp.

 

xs650 and jdenenberg,
Sorry for the misunderstanding. I meant that putting 2.5 amps into the High Voltage battery would barely offset with the amount of draw from 12v accessories when the car is the car on, with the gear selector in Park.