We all know the 158V NiMH drives the IMA Motor and the Aircon Motor. Does HONDA step down the 158V to 12V to run all devices including charging the Lead Acid Cell? Just wanted to know how much the NimH batteries are being loaded.

That's a great question. I will check it out in the service manual.
Indirectly, everything runs off of the 158V, because when the 12V needs charge, it does not get it from the ICE via an alternator, but rather the 158V via a DC-DC converter.
I'm pretty sure that not many (if any) accessories run off the NiMH.

EDIT: Oh yah... the A/C for sure runs of the 158V when autostopped.

After looking in my service manual, it does not seem that any accessories run directly off the IPU(Intelligent Power Unit/158V NiMH Battery). The IPU only powers the electric motor, which can operate the A/C compressor and start the car (the 12V can also start it). Other than that, the drain is on the 12V, which is recharged via the IPU, unless you have a solar panel to help reduce the drain.

I'm interested in the electrical system of the HCHII - does the service manual include a lot of detail about it?

Hopefully this isn't considered a thread hihacking, I'll start a new thread if appropriate...

I have also been thinking about the 12V system of the '08 HCH that I picked up a couple of weeks ago. I have an amateur radio that I plan on installing (http://www.rigpix.com/kenwood/tm732a.htm). It draws around 1.5A - 3A while receiving (which is probably 95% of the time), and can draw up to 11A while transmitting (depending on the RF power setting at the time; will probably be in bursts of 30 seconds to 1 minute). In my previous car, I used it with a 35Ah 12V battery that I brought into the house to charge periodically, but I'd really like to not have to do that moving forward.

I guess these are my questions:

1. Will a 3A load 95% of the time (while the car is on) with occasional jumps up to at most 11A for brief periods (30 seconds - 1 minute) be an issue for the HCHII's electrical system? I'll probably wire the radio directly into the 12V battery.

2. Am I better off keeping the 35Ah battery in my trunk? It weighs around 25 pounds.

3. Will the FE trade-off be about the same between using the car's 12V system and using a separate 35Ah battery? I know this is probably a tough question to answer.

[UPDATE: Some of the other threads regarding ham radios answered #4 for me]
4. Not necessarily 12V related, but does anyone know of RFI issues caused by the HCHII's systems? I have heard the Prius II causes some RFI in certain bands. I guess the reverse of this might be an issue too (i.e. the radio causing problems with the HCHII's systems, but I'm not as concerned).

I have really enjoyed reading the threads on this board so far, and have been impressed with the knowledge that is shared by everyone.

- Lawrence

1. No, that will not negatively affect your 12v system. 3A will be fine, and the high current surges are not "that high" for a 12v system. The DC/DC can handle it.

2. Keep it in the trunk if you like, if you'd perhaps want more 12v capacity. You can have your car charge it by hooking it in parallel with your car's 12v battery. Put a fuse on BOTH ends of the +12v wire that passes through the vehicle, if you do this. You can't do this in a normal car because the starter will draw too much current and blow the fuse. Yay IMA..

3. Removing 25 pounds from your car will help your fuel economy very slightly. Using ~50 watts from the car's 12v system will "hurt" your fuel economy very slightly. It's probably a better idea to use the car's 12v system. A lighter car accelerates quicker using a bit less gas.

4. If you're worried about EMI you can reduce conducted EMI (via the car 12v system) by using a low-pass filter (I'd make a common mode choke followed by a couple LC poles). I don't know where your antenna is or what band your radio is on, but I'd try it first then work on filtering if you find that you have problems. There's a good chance your 12v radio has pretty good filtering anyway. Ignition coils can be pretty noisy things in ANY car.



-
Martin

Besides the service manual, there is also an electrical manual available:


http://www.helminc.com/helm/product2...8H0QQ63WCM3EKF

http://www.greenhybrid.com/compare/m.../car/5679.html

That's great! I just have to justify the $90 now.

Thanks

Just think of the possibilities...

In my opinion it is a must have and well worth it the money.


Cheers;

MSantos

Yet another Canadian perspective on hybrids

You could always say you saved $90 in gas money over "x" amount of time, and can use that to buy the manual.

http://www.greenhybrid.com/compare/m.../car/5679.html