Amp ideas for high DC Voltage (144-196VDC)

[Hades16x]

Hey all,

I'm on the beginning leg of my 1983 Mercury Capri EV conversion. I have various motors and controllers picked out but I cannot finalize plans until I decide on a battery pack voltage. I almost pulled the trigger on a 196VDC pack setup - but I cannot figure out how I want to power car audio from said pack.

I have gone back to the drawing board.

Individual Cell: 3.2VDC nominal (3.35VDC fully charged)

180Ah with max discharge @ 2C

1) 196 VDC pack: ~ 35 kWh + find some way to provide a high amperage ~14.4 VDC to car audio. $15,000 - 100 mile range without audio

2) Parallel 144 VDC banks ~26kWh/ea and find a way to drop DV voltage. ~$22,500. 180 mile range without audio

3) 196 VDC main pack with auxiliary system consisting of 3-4 5 cell packs in parallel. ~$19,000. 100 mile range. Audio does not impact range ( but requires a second charger)

Each 5 cell audio bank would start at 16.75 VDC and immediately drop to nominal pack voltage at 16 VDC. Each pack would be 180 Ah:

Target power per bank: 1C = 2.880 kWh

Max power per bank: 2C = 5.760kW0.5h

I require ~70 mile range. I'm leaning toward option 3 because it seems easier and I can tune aux_pack to die at the same time as drive_pack.

I would like to find a car audio amplifier capable of higher VDC input based on a multiple of my max/nominal cell voltage. 6 cells starts at 20.1 VDC and quickly drops to 19.2 VDC. Can a SAZ handle this? Anything else. Need monoblock and 2/4 channel.

Option 4: since my motors are already going to be 3 phase AC, it would be easy to convert 196/144 VDC into 120 VAC and run home audio/rackmount equipment (Crown?)

Any thoughts, suggestions, or creative ideas would be greatly appreciated.

Thank you,

Michael

[Broke_Audio_Addict]

Ummmmmm $20k into an 83 capri?

[Hades16x]

Ummmmmm $20k into an 83 capri?

Yes, batteries are very cost prohibitive. I am trying to work on a group buy as several companies give tiered flat percentage discounts based on amp hours purchased.

The car is special to me - it does not haven't to be special to you. With that being said, the car was willed to me and money was provided explicitly how I want to re-do the car. 5.0L Fox Bodies are a dime a dozen.

I do admire your post count, but I would appricate a more constructive response to the question(s) asked.

[Broke_Audio_Addict]

No one here is running almost 200vdc to their amp if I was you I'd go the two separate charger's route and do maybe a 14v bank of batteries.

[boom50cal]

3 phase AC motors, makes me think you could run a transformer to get 120v. Cool idea. Really cool idea. DC power to AC power... sounds like a lot of money. LOT of money...

Intrigues the shit out of me.... What type of batteries will you be running?

[Hades16x]

No one here is running almost 200vdc to their amp if I was you I'd go the two separate charger's route and do maybe a 14v bank of batteries.

I am not trying to run 144-196 VDC to my amplifiers. I am trying to figure out how to appropriately step the voltage down with the most minimum hit to my range.

3 phase AC motors, makes me think you could run a transformer to get 120v. Cool idea. Really cool idea. DC power to AC power... sounds like a lot of money. LOT of money...

Intrigues the shit out of me.... What type of batteries will you be running?

Currently looking at CALB 180Ah

[Broke_Audio_Addict]

If you are taking on building something that is potentially lethal and you can't even figure out how you would step the voltage down I think you should reconsider building it yourself.

First place I would look is how they do it in a production ev.

[Hades16x]

If you are taking on building something that is potentially lethal and you can't even figure out how you would step the voltage down I think you should reconsider building it yourself.

First place I would look is how they do it in a production ev.

Broke_Audio_addict,

I feel as if we have gotten off on the wrong foot. Perhaps I shouldn't have made my OP and two responses from my phone. Since I do not know how to interpret your responses, I will assume the positive by believing that your intentions are to prolong and save human life rather than belittling my intelligence.

Before we begin, I would like to correct you on one thing. There is nothing *potentially* lethal about these voltage and current levels - they are absolutely lethal. The whole reason behind the original post was to gain insight from people that may have already discussed or (safely) implemented this.

Onto the topic at hand - you're right, I have absolutely no freaking idea how to step down 196 VDC to ~14 VDC under the circumstances required for an EV conversion. As you well know, the most simple way to step down voltage would be to dissipate energy (Linear Voltage Regulation). Close to 30% of all of my circuit design projects during my undergraduate in Electrical Engineering (Bachelor's) used an LM317. However, as you well know - the LM317 has a maximum input voltage of ~37V and has a maximum Iout of 1.5 amps. Using the most simple High to Low DC converter (assuming a pack nominal voltage of 37 VDC) would require me to dissipate ~35 watts of thermal energy for 14 VDC @ 1.5 A.

The next step, as you well know, would be switched mode conversion. Do you have NI Multisim or any Spice simulators? I'd gladly share my switched mode design for some pointers on how to achieve higher efficiency while *drastically* improving Iout. My current design will step down 196 VDC to 14 VDC with a maximum Irms of 35 A and a burst output of 47 A. After 10 seconds of 47 A output, NI Multisim indicates transistor meltdown. With this said, we are still discussing 196VDC to 14VDC @ 35A with an efficiency of 67%. That's just shy of 500 watt output. Even if I could match and load balance these switched mode converters, ~ 300 watts to the 2/4 channel + 2000 watts to the LFE, I need to hand manufacture at least five of these. The size, cost and time required to do this greatly exceeds what is commercially available (14VDC/30A).

I understand that current state models for marginally higher VDC+ stable car audio amplifiers is to increase output. In contrast, I am looking for high VDC amplifiers to achieve comparable output at lower current draw.

To Broke_Audio_Addict: I appreciate your comments and your positive outlook toward safety. Unfortunately, the *ideal* EV (Telsa) does not provision ~200A @ 14V for car audio. I haven't really looked at Nissan's Leaf - but I'm pretty confident that anything "innovative" in the mass produced EV space is going to come from Elon Musk. If you have any 144/196 VDC to 14 VDC schematics, I'd love to see how you implemented them and how they simulate in Multisim.

Keep the comments coming.

[Broke_Audio_Addict]

If you're so smart why did you come to a car audio forum and ask questions about something that no one here has ever nor will any here likely ever deal with?

Also stating it is potentially lethal is stating that the project you are working on has the potential to kill you not that it wouldnt always be fatal because it most assuredly would be if something went wrong.

I'm interested in knowing what's making you think that your current draw for your audio alone will be 200 amps at 14v?

What are you planning on running?

And I'm not trying to belittle you but you came here asking questions that most likely no one here has the answer too.

[Hades16x]

If you're so smart why did you come to a car audio forum and ask questions about something that no one here has ever nor will any here likely ever deal with?

Also stating it is potentially lethal is stating that the project you are working on has the potential to kill you not that it wouldnt always be fatal because it most assuredly would be if something went wrong.

I'm interested in knowing what's making you think that your current draw for your audio alone will be 200 amps at 14v?

What are you planning on running?

And I'm not trying to belittle you but you came here asking questions that most likely no one here has the answer too.

1) Because I am in need of help and decision making. I have not made any comment that states that "I am so smart". You authoritatively responded with intelligence and concern. I mentioned my degree to abolish any belief that I was an idiot WRT electronics. I came to a car audio forum, specifically SMD because my questions are 100% audio related. Any online forum will be filled with people both less and more intelligent than myself.

2) I am working on both an electronic and mechanically kill switch - the latter being similar to bolt cutters separating pack from load.

3) In my 2011 Fiesta, I run 2x SA-8 V.2's running off of an Alpine PDX M12 and Polk MM651 + 6501's off an Alpine PDX F6. I'm very happy with the setup. Ideally, I'd like to mimic the setup in an EV environment. The issue with a secondary pack is that everything must be 100% powered by batteries over the course of a 100 mile trip.