Author Archives: Will@FluxAuto

How a Lead Acid Battery Works

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A friend of mine asked my advice on using cheap car batteries to put together an electric motorcycle. This video about lead acid batteries is pretty helpful in explaining why car batteries are not ideal for energy storage on electric vehicles:


The important thing to pay attention to is the energy density vs. power density comparison. Your typical car battery is built for outputting a large amount of cold cranking amps (CCA) for a brief duration to start your engine. From there it is immediately recharged by your alternator once the car is running. For that reason, the lead plates are very thin. If you ask a car battery to continually discharge over a long period of time to a very high depth of discharge (DOD), you will permanently damage the plates and the battery’s ability to hold energy.

Lead acid batteries are a good way to build an inexpensive electric vehicle, but it’s pretty important to use a deep cycle battery. Odyssey batteries don’t count, either. They are sold as “deep cycle” batteries, but they are absorbed glass mat (AGM) that are even more susceptible to damage from deep discharging. The way to go is golf cart batteries since they are designed with much thicker lead plates to safely discharge a large percentage of their stored energy. The EV community seems to favor batteries from the Trojan Battery Company. Your best bet will be to try and arrange a batch buy at a local dealer since they’ll be really expensive to ship due to weight. Generally speaking, lead acid batteries will give you a much cheaper battery pack compared to lithium ion, but you only get about half the benefits in terms of weight, discharge performance and longevity. They also need constant maintenance in terms of needing to be watered with steam distilled water about once a month. I would recommend doing a lead acid battery EV on a light truck so you can mount the heavy batteries (somewhere in the neighborhood of 1200 extra pounds) between the frame rails or in the bed and because there will be a lower performance expectation. Another thing to keep in mind is that we’re currently able to recycle lead acid batteries very well simply because they’ve been around for a long time.

Source: Engineer Guy Video on YouTube

Blastolene Piss’d Off Pete – Jay Leno’s Garage

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Jay Leno brings the creator of his Tank Car, Randy Grubb, onto his show to check out his latest creation. Piss’d Off Pete is the fourth car in Randy’s Blastolene line of gigantic automotive sculptures. It’s a scaled up hot rod built around a twin supercharged 2-stroke Detroit Diesel V12 that was originally used for industrial plant work. Each cylinder is 71 cubic inches which translates to a total of 14 liters. We’ve featured it here on the blog before getting frantically rev’ed to it’s 2800 rpm redline. Here Jay and Randy go over the inspiration and finer details of Piss’d Off Pete as well as take it out for a spin.


Source: Jay Leno’s Garage on YouTube

Rockhard Racing at W.E.Rock Nationals 2012

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The Rockhard Racing Team consists of 23 year old driver Justin Hall with his father Mark as the spotter. Justin has been wheeling since he was 16 years old when father and son bought a Suzuki Samurai. They now compete professionally with their Unlimited Class buggy in the Calrocs and W.E.Rock series. Hit up the Rockhard Racing Website to find out more about the team, their sponsors and their campaign to raise money for the fight against Crohns disease. Also check out this footage of the guys killin’ it at this year’s W.E.Rock Nationals in their tough little diesel buggy:


Source: Rockhard Racing and Busted Knuckle Video on YouTube

Translogic Visits Tech Shop San Francisco

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This week’s episode of Translogic takes us to Tech Shop in San Francisco. The Tech Shop franchise is a fabrication workshop co-op where you pay a monthly membership fee and take classes to be trained on the equipment they have. I have a membership at the Tech Shop here in Raleigh and have really enjoyed it. I’m going to be using the CNC mill, metal shop, CNC plasma cutter and welders to do the EV conversion on the RX-8. It’s been great to learn all the fabrication skills to supplement my engineering degree. I find myself revisiting all the ideas for inventions that I’ve had in years past now that I’m actually able to make things. If you’re in the Bay Area, the Triangle area in NC, Detroit or Austin, then check out the Tech Shop Website to see what your local shop has to offer. The Translogic video showcases some of the success stories that were born in the San Francisco Tech Shop including a little roadster powered by a BMW motorcycle engine:


Source: AOL Autos on YouTube

Steam Whistle Brewing’s Retro Electro

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The Retro Electro is a 1958 Chevy Apache that was restored and converted to an electric vehicle over about a year and a half by Vancouver based Steam Whistle Brewing Company. Steam Whistle is known for their fleet of vintage vehicles used for their local deliveries. The idea for the Retro Electro was born at one of their employee round table discussions on how to make the company more environmentally responsible. It’s powered by what appears to be Thundersky batteries and an Azure Dynamics AC-90 AC motor and inverter connected directly to a Ford 9 inch rear end. They claim the setup makes 90 horsepower and 456 foot-pounds of torque (this figure is probably at the wheels with the short ring and pinion gearing) in the videos. Steam Whistle also made sure they weren’t simply redistributing their carbon footprint by making sure the power used to charge the truck came from a local windmill farm. Breathing new life into a cool old truck with an electric conversion is just awesome. Check out their 7-part video series detailing the whole project.

Part 1: Birth of the Idea

 

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