EcoModder Forum How many batteries do i need?

Register Now
 Remember

 Submit Tools LinkBack Thread Tools
 06-17-2014, 03:47 PM #1 (permalink) EcoModding Lurker   Join Date: Jun 2014 Location: Socal Posts: 2 Thanks: 0 Thanked 0 Times in 0 Posts How many batteries do i need? Im an electrical engineering student and im doing a summer research project regarding making a hybrid system with a turbine engine as the power source. This turbine puts out 480VAC 3 phase and has a maximum power output of 60KW. Im wondering what sort of battery(s) would be needed to handle that sort of input. Right now for viability purposes we are looking at using lead acid batteries (car batteries). Im wondering how many of these i would need to hook up in series/parallel so that they wouldnt get instantly fried. We have a rectifier to convert the VAC into DC, and a transformer, though im not intimately familiar with their specs yet. From what i understand batteries use the amperage-hour unit to determine their capacity, but i dont really understand the A-H unit. So hopefully there are some pretty knowledgeable people here in regards to the power side of things. Edit: i just realized there is a battery subforum, maybe this needs to be moved there...
 Today Popular topics Other popular topics in this forum...
06-17-2014, 05:24 PM   #2 (permalink)
Master EcoModder

Join Date: May 2012
Location: USA
Posts: 2,643
Thanks: 1,503
Thanked 276 Times in 226 Posts

You will just vaporize the electrolyte.

Not enough information, we need to know voltage and amps. Assuming what you said is correct that will be 480 volts dc and 60kw or 125 amps an hour.

480/12 = 40 deepcycle group 27 batteries in serial. They are rated at like 115 amp hours, so to be safe, assuming full 60kw output do 2 strings or 80 batteries.

Quote:
 Originally Posted by Vic Im wondering how many of these i would need to hook up in series/parallel so that they wouldnt get instantly fried.

 06-17-2014, 08:00 PM #3 (permalink) EcoModding Lurker   Join Date: Jun 2014 Location: Socal Posts: 2 Thanks: 0 Thanked 0 Times in 0 Posts Actually i think i understand, the limitations are actually on how long wed like to run the motor. The 3 phase VAC can be rectified and transformed down to 14V (max charge voltage for a car battery). So the electric motor im looking at has a typical draw of 80A. To run this for 30 mins i would need 40 Ah, which is typical of one battery. Unfortunately this doesnt sound right. In addition if i am putting out say 30Kw from my powerplant and with the current planned setup i can run it for about 2 hrs, so for a whole tank i get about 60 kw, but i dont know the internal resistance of a car battery to figure out what that is in Ah.
 06-17-2014, 09:17 PM #4 (permalink) Master EcoModder   Join Date: May 2012 Location: USA Posts: 2,643 Thanks: 1,503 Thanked 276 Times in 226 Posts If you are a real engineer student, you should go 170% over your needs for a good safety margin. Then when it comes to battery ratings of amp hours that assumed 100%, however if you go to 80% or more you will measure your lifetime in weeks vs years. So in theory, assuming no resistance or losses, your 80 amp load will likely get 20 minutes from your 40 amp battery.
 06-18-2014, 12:28 AM #5 (permalink) Master EcoModder     Join Date: Jun 2008 Location: Utah Posts: 975 Civic DX (sold) - '97 Honda Civic DX 90 day: 34.15 mpg (US) GTO (sold) - '04 Pontiac GTO 90 day: 22.62 mpg (US) Green Brick (sold) - '06 Ford Escape Hybrid 90 day: 31.93 mpg (US) Thanks: 193 Thanked 311 Times in 220 Posts 80A at 12v? That's not a very powerful motor compared to the generator and what would be required to move a decent size vehicle __________________ Prius Thread Camry Thread E-Bike Thread

 Thread Tools

 -- EcoModder Skin -- Mobile / Lightweight skin Contact Us - EcoModder.com - Archive - Recent Posts - Top

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com