Friday, June 26, 2009

My battery transporter

 

My late grandpa-in-law was a WWII marine, I decided to keep this and use it as my battery transporter. I coated the inside with rubberized undercoating. It says “For A.C. or Battery operation”, pretty close to “For RC Car Battery operation” :)

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Going LiPo

When I had my first Tamiya’s all the batteries where NiCd’s. When I started on my second stint of Tamiya’s I got all NiMh’s, I wanted the extra run time and the price was half of what the LiPo’s where. Lately I’ve been able to get 4000mah lipo’s in the $40 range from Hong Kong (ebay). When you switch to Lipo in a Tamiya there’s a few things you should know.

  1. You need a charger that is capable of charging LiPo’s
  2. You need a speed controller or a voltage cut-off device so you don’t permanently damage your battery.
  3. You probably need a STICK PACK! (the first lipo I bought was an $80 squared pack, I can only use it in my TT-01D after dremeling it.

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The battery above is my favorite so far, I’ve gotten them through RC-Union on Ebay. I’ve replaced the Tamiya plug with Deans Ultra’s.

Why go Li-Po?
• Up to 30% longer runtime than traditional NiMH/NiCd (of the same capacity)
• Up to 40% lighter weight than traditional NiMH/NiCd (of the same capacity)
• Precision cell fusion technology virtually eliminates internal resistance
• Li-Po power delivery ensures maximum power throughout the discharge cycle
• Can be used and recharged unlimited times per session
• Less energy is lost to heat equals greater power output
• Fits 90% of 1/10 scale chassis with little or no modification
• Battery can be charged days, even weeks, ahead of time
• No complicated maintenance or conditioning required
• Cost is far less over time due to a lifespan that is up to 10 times that of NiMH/NiCd

LiPo batteries have a "C" rating which tells you how much current it is safe to draw from your battery. It's expressed in terms of the capacity C.

So my 4000mAh 25C battery is good for 100A (25 x 4000mA/1000).

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My charger, this has a battery temperature sensor (for safety) and I also have a USB cable for it which can  graph charging and discharging. More for fun than anything else, I’ll play around with it more and post later.

Sunday, June 7, 2009

DF-03 MS

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Finally a REAL dirt car for me to drive. This thing is so much fun to drive. I bought it down at ultimate and decided it was better to spend the extra money for the MS edition instead of hunting down tons of hop-ups later. I decided not to follow the paint scheme or sticker job from Tamiyal. Not a big fan on pink on blue flame job really. I tried some iridescent paint, but on a see through lexan, that doesn’t end well. So I back coated it with white. So I guess my paint scheme is “iridescent white”, it’s subtle which I like.

A big surprise with this kit was that it didn’t come with any tires. A first for me, pretty weak. So I had to go back to ultimate and ask for a recommendation. I ended up with LOSI IFMAR Silvers (LOSA7283S Front, LOSA7367S Rear). 

I picked up another Spektrum 3000 reciever, moved over the Futaba MC401CR speed controller over from my mini cooper and got a Checkpoint 13x2 competition off-road motor. Battery is a Intellect 7.4v 4000mah 25C Hard Case Stick Pack Lipo they’re about $45 from rc-union on ebay. This thing hauls, so much fun to drive!

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