Prius Battery Car Audio High Amperage Output

I

icecube57

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Me and my brother want to know how hard would it be to take a Prius battery with the 38 7.2v 6.5AH modules and rearrage them into a 14.4v nominal system 16.8 fully charged. We ask because we plan to compete in IASCA, DB Drag and NOPI car audio shows this year. We can source alts with adjustable voltages and we have dc to dc converters to step the voltage back down to 12v for the car components.. We need the voltage high to get the maximum power out of the amps. Normally this is 14-15v. If it was 16.8 fully charged it would probably sag 2v under load. Under the configuration we are considering we are going to do 2p and 19s this will give us a 14.4v pack with 123 AH with a theoretical top discharge of 1200A we need 600-800A for 20-30 seconds for burps during our runs.. is this possible. Before the only way we could keep our voltage solid was to use 6v deep cycle batteries in a 3s configuration... salvaged from forklifts they stayed pretty solid but weighted over 1500lbs in the bank that we had which put a shitload of stress on suspension components but the voltage didnt budge in the 3s 4p configuration. Input would be greatly appreciated.
 
We also consider a123 in a 4s 5p or 5s 5p configuration and hook them up to the amps individually. They would last long enough for the run .... Could be fast charged in no time. Have the discharge that we want... but they dont have the runtime they we want for everyday use... thats why we are considering the prius modules because then it can be used for competition and in everyday street use.
 
That would be 2S19P (yikes!).

Another option is to avoid the inefficiencies in the amplifier's power supply itself - and run the batteries as the rails.

Find out what the rail voltages of the amplifier are, and you could run the batteries direct this way. 600-800A at 14.4V = 72A at 160V (assuming 80 V +/- rails).

Remeber that these are still NiMh and will sag. A few people also do shorter runs (or at least you could when I did this years ago) to reduce power requirements/heating effects etc.
 
I used to play the dB game in highschool. I used to run 6x optima deep cycle batteries in parallel.

Then I realized that the first half or even 2/3rds of my amp was just a switching DC/DC power supply to get the voltage up to 40-60v (depending on the power of the amp). So, I realized I could make much much more efficient and higher power amps by using the car's 12v source to power all the signal processing electronics, and feeding my own final output stage right from the 6x batteries, but this time in series rather than parallel.

What I'm getting at, is why not leave the prius pack all in series, and have it be the amps power supply?

If you bought any D-class amp to use for signal, you could use some of those badass 200v rated Fets in the TO247 cases, use the fet switching signal from the little d-class amp for source to switch them, and easily make yourself an amp that could pull the peak power possible from the Prius pack. You could have a +40kw HV amp for 200-300 bucks in parts and not even a whole lot of labor. You would be way more efficient than any regular amp which spends a ton of energy and effort towards getting 14vdc up to a voltage capable of putting a lot of power into the voice coils.



Just seems silly to take a perfect high voltage source, drop it to low voltage, then inefficiently convert it back to high voltage to make use of it.
 
Healthyyoung- You posted while I was typing :) Looks like we had the same idea :)
 
Yeah you are right we could supply it directly to the rail and it would cut alot of the losses but we are still looking at the AH capacity too. But we are using reversed engineer US Amps which are nicely regulated with dual power supplies and have very clean power. With modified mosfets ofcourse........ We are trying not to buy the kinetic batteries which are 16v and 60AH and 349 a pop. These amps will pull whatever the hell it wants as long as the voltage is where it needs to be... so they can exceed 300A+.... Since we like to tune our boxes low.... we need more power at the low end.... we are a different breed. We make our boxed for street use but can compete in comp but our boxes peak their loudest in the 30-40hz range... and thats what we burp and and we can get into the mid 165db. After runs in our shows we let it rip with regular music when the competition tune their vehicles to play 1 note which is about 70-80Hz and if they try to play anything else it sounds like total garbage.
 
OOOO i might have to look into the homebrew... gotta check the rule book too... Seems like an unfair advantage... would be in a totally different class... depending on if it were inches or wattage.... i would pwn both with that...

Most runs are less than 5 seconds for the pros... I know my frequency but it changes so i might have to cycle up in Hz in the summer and lower in the winter. The resonance freq changes in the vehicle with temperature...

Thought about the rail voltage i gotta check it but you have a point... more voltage less draw... needing less capacity... I realize the NimH will sag but look at that parallel string... its stout... maybe if i up it to 25p... if we were running the 14.4v...

Also trying to keep thing as commercial or stock as possible... Ive never been challenged for a review... dont want to.. I already think i have and edge with the amp...
 
If I were you, I would buy the smallest D-class amp I could find, then amp it's FET switching signal.

Then get a giant heatsink from any amp, mount the guts from the small D-class amp inside it, and bolt down dual banks of 8 T0247 200v FETs. Feed them right from the Prius pack at full prius pack voltage. Throw some caps in there right off the FETs to help stiffen things. As low of ESR as you can find. Then run the output to your voicecoils. Done! May be able to reach 50kw that way.

If you look at your giant US amp, you will notice the first 1/2 or more of the amp is all powersupply/voltage regulation, because it's trying to wish it had a higher voltage power supply than 14vdc to feed it.

If you are going to involve a Prius pack in your build, take advantage of it!

Or, even my 84v LiPo pack for my E-bike is capable of 50kw drain for 2 minutes continuous. That's a lot longer than your speakers are going to be able to handle :)
 
I'm sorry to even ask this, but I'm old so I can ask what I want to! Why would anyone want to output to a speaker at 165 DBA. That wil vaporize your eardrums in a millisecond! I don't get it?
otherDoc
 
Before ebikes, my main hobby was actually dBdrag racing :mrgreen:

i was in street A but my team (teamXmax) was superstreet 1-2 and 3-4.. and we had an xtreme car too.

I remember the fre last mV of the battery was so important to keep the last dB/10!

Wayne is a nice guy to meed as well! guess what?? John Henry ( the first dbdrager that had the world record after team gate gad 168dB in the midle 90' had reached 174.7dB in his green astrovan...

and he came here!! in E-S.. his nick name is oyeah and i got my famous 1500$ delta wye contactor from him!

did you saw my 4s4p battery on youtube used with a 5000W amplifier and we got 154.3dB on my calibrated audiocontrol using 2 10" in a crx with 16 A123 cells.. 260A draw and still above 12V

YOU MUST USE THESE CELLS!!! their energi density is excellent!

[youtube]JIcZveKHZyI[/youtube]
 
If it were at 6s 5p it would be great for competition... thats it though cant really use it for everyday..... thats pretty impressive... breating 150db is freaking hard unless you are tuning and designing it to peak at one note... thats hard in its self but its easy. I see alot of people using these damn premanufactured areo dynamic ports. When you state your claim to fame through the whole spectrum thats respect.. My everyday setup only does 151 at 37hz... after 3 sets of subs and 5 boxes. But thats accomplished through pure mdf only. Tweaking volume port size and internal baffels while trying to compensate for high losses due to large boxes sub displacement and being able to peak low notes. That wastes alot of energy into heat. If you can control excursion of the sub you cant put the power into it across the spectrum. You have to move air but you have to dampen how much it moves to be able to peak at a given note without the sub unloading itself. People say that there is no skill involved and anyone can slaps stuff together and think they are loud.. My brother does 165 in his Chevy 20 cargovan with (8) 15"s He has sponsorship with a company called Interfire. They are solid but not superb quality subs. We can say we can dump power into them and they take it better than some of the better known companies. We manage to smoke a sub froma company called DB Drive. We bought 1 WD 15 and it plays music like a champ. We go to do a burp at 12000w... nothing but burnt resin.

But we have so many pressure losses with sheet metal flexing... windshield flexing..doors flexing.... leaking around the seals... We dont have the time or money to fix doors with concrete and bolting plexiglass windshields and doors and all of that... We gotta drive to work in the morning lol We did find a cost effective way to stiffen the sheet metal panels... it involves resin sand and high R value home insulation. Lighter and it gives a solid thud when you strike the side wall of the vehicle.
 
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