How do I convert to LiPo?
 

I have a few vintage Tamiya cars from m the 1980s that I pulled out of the attic. I had them when I was younger and I now want to play with them with my boys. I have a Frg, Hotshot, Hornet and a Falcon.

I haven't kept up with electric technology so the only point of reference I have are NiCad batteries and chargers. What do I need to get to convert these cars to LiPo batteries? I would like to do this in a way that doesn't alter the cars so I can keep them as original as possible. In other words I would like to not cut into the frame of structure if the cars.

I would think I would need new ESCs, batteries and chargers. I don't know if I would need anything else or where to start with what ESCs, batteries and chargers I should get.

if anyone can help me with where I should start I would appreciate the help.

Bob

First you would need a charger to properly balance the cells in a LiPo pack. Depending on battery compartment shape on RC, a normal rectangular shaped 2S hard cased LiPo battery may not be the best fit. There are few LiPo packs that are shaped like a sub-C stick pack....https://hobbyking.com/en_us/turnigy-...tick-pack.html.

I would highly suggest getting an ESC that has LiPo settings. You want an ESC with Low Voltage Cut-off (LVC) so that a LiPo battery will not be over discharged.

If choosing to stay with brushed motors, the Hobbywing QuicRun 1060 60A ESC should be on top of your list.

A charger with great specs for the person who want to get introduced to LiPo batteries... Hitec X1 Mini- AC/DC Charger

Some of the best places, IMO, that will inform a person to the use of LiPo batteries:

http://www.rogershobbycenter.com/lipoguide/
http://www.mrpositive.co.nz/understa...ipo-batteries/
RC Resources for the beginner
http://www.rchelicopterfun.com/rc-lipo-batteries.html

If I convert to LiPo batteries what is the run time with a stock 570 motor?

Run times with stock Tamiya/Mabuchi 540 will depend on capacity of battery used and gearing; not to mention driving style. You will get long run times from a 4000~5000mAh battery. I will usually get around 20+ minutes on a 4200mAh 2S LiPo battery while running a light 2wd buggy powered by a mild 17.5T brushless motor.

Theoretically, if a 27T motor draws 8 amps and you have a 8000mAh (8Ah) battery, you should have a motor running for approximately an hour. Take that same motor, with a 4000mAh (4Ah) battery, and you will see approximately 30 minute run times....I think I got the math right.

That's a whole lot longer than my old batteries. Thanks for the info and have a Merry Christmas

What discharge rate should I look for? Hobbyking also offers a 25C pack for less $$: https://hobbyking.com/en_us/nano-tec...tm_campaign=us

Would this pack work?

That battery pack should work just fine with brushed motors and brushless motors even a 20c pack will work. Capacity has to be looked at along with c rating. Example 1000mah x 25c = 25a discharge rate. So your linked pack has a 4200 x 25c = 105a discharge rate. Brushless motors are current (amp) hungry motors brushed not so much. Things change with motor size, higher or lower turns, voltage used but for the Tamiya 540 and other 540 brushed motors that you would put into a Tamiya the lowest I would go is a 3000mah 20c pack.

The best way to gauge your runtime is to consider how long you could run with your 1200maH nicads. Depending on gearing, you were probably getting between 5 and 8 minutes on a battery pack. If you are going to a 3000mah lipo, expect between 12 and 20 minute runs.

Thanks this is helpful. I was getting 5 to 8 minutes with the old packs.

I scored a bunch of chargers from craigslist that will help get me started. I also ordered ESCs from eBay. Now I need batteries.

I got around to getting the Hobbywing QuicRun 1060 60A ESC that you suggested. It's been a year of long hours at work and projects at home so I haven't concentrated on the RC cars. I ordered the ESC earlier in the year and didn[t recieve it from the seller in China. I put in a complaint through eBay to find out that the seller closed their account. I got ripped off. The good thing is the eBay refunded my money. I bought a ESC from a reputable seller and received it.

The ESC has one connector that goes to a Futaba receiver. I expected two; one for the throttle signal to the ESC and a second for power to the receiver. Does this ESC not provide power for the receiver? Do you use a receiver battery pack with this ESC?

Thanks,

Bob

The ESC will power the receiver/servo. Just plug the ESC into channel 2 on the receiver.

After checking the manual, it definitely could have been written better, and with more diagrams how to hook up the wires. The Hobbywing QuicRun 1060 speed control has battery eliminator circuit (BEC) that provides power to the receiver/servo from the main battery. The same goes for Tx/Rx manuals...a lot of them could be better explained. On almost all receiver's channel inputs, the inside pin is the signal, middle is the (+) positive, and the outside pin is the (-) negative.
https://cimg5.ibsrv.net/gimg/www.rcu...d3ecd3daf6.jpg


https://cimg7.ibsrv.net/gimg/www.rcu...7eb2de9249.jpg

Thanks for the reply. From what you sent it sounds like the ESC is powered by the LiPo battery, correct? I know to connect the ESC receiver connector to the throttle port on the receiver.

Thanks again for the reply.