Battery nerds: make a spare battery for RC car?

ReferrerMrDixit on 23/05/2017 - 08:13
Last edited 23/05/2017 - 08:15

So, bought an RC car for my little boy : http://m.gearbest.com/rc-cars/pp_536608.html

Comes with a battery pack and USB charger (presumably a dumb one) .

According to specs, battery pack is: 6.4V 400mAh 2S lithium-ion.

According to this, it seems to be two 14500 batteries wrapped with an EL2P connector.
http://s.aliexpress.com/a6j2YJnm

I have a Nitecore smart charger and a shitload of eneloops at home.

So :
1) would you use the USB charger that comes with the car, or cut the battery pack open and use the smart charger?

2) I'm assuming I couldn't strap some AA eneloops together to make a spare.

3) to build a spare battery pack, what 14500 batteries should I buy?

4) is the original or spare battery going to explode (is it worth using a fire bag)?

Any advice appreciated.

Electrical & Electronics

Comments

  • ESEMCE on 23/05/2017 - 08:59
    +1

    Eneloops are 1.2V, Lithiums are 3.7v each, so just to get around the right voltage, you're going to need 5-6 eneloops (6V-7.2V)! That's a lot of volume for what I assume is a tiny RC car!
    If you go with 5 cells, 6V, expect a reduction in performance at a minimum (less power, more weight) and the batteries are going to drain fast.
    If you go with 6 cells, you'll probably see similar performance to the stock battery more power but also more weight. It's not going to look pretty.

    • MrDixit on 23/05/2017 - 18:32

      Yeah, figured, thanks. Car is low slung and flips over, so I don't think 6 cells are an option. Know much about 14500 Lithium ion cells by any chance?

      • ESEMCE on 24/05/2017 - 08:12

        Nothing… Like I didn't even know it was a battery, I initially thought you meant 18650!

        • MrDixit on 27/05/2017 - 16:59

          Yeah, same :)

          I get the feeling I could use two 18650s but I'll wait till the thing lands and then check it out.

          Thanks anyway.

  • [Deactivated] on 28/05/2017 - 10:24

    I have had a run of cuatomising elecrronics to hold more or change batteries.
    Easy to do just need an idea and make sure you have the correct voltages.

    • MrDixit on 28/05/2017 - 19:52

      I trying to learn about how to safely charge these, and whether I can build or buy cheap spare batteries. I've got an opus charger that handles individual cells, but nothing that does balanced charging or connects to EL-2P connectors. The USB charger the car comes with looks a little dangerous…
      Any suggestions on where to read more or decent battery suppliers? Looks like hobbyking has cheap two cell batteries.

      • [Deactivated] on 28/05/2017 - 20:43

        i went J car. and there they have some great options for my needs which was being able to swap out flat batteries if i need to. so i have a 4 AA caddy that can be used for my new beast BT speaker plus the caddy has a usb port for a 500mAh output to charge usb devices, the bigger the AA rating the long it lasts or more it charges.

        i have purchased some cheap batteries online and they dont last as long or a just plain wrong.

  • ESEMCE on 29/05/2017 - 08:46

    From what I read, there is no included battery with the car… Wouldn't be surprised if Gearbest have removed it so they can get away without having to comply with shipping regulations for Lithium batteries.

    So building your own "pack" with quality cells looks like a great idea.
    Unfortunately it makes a $30 car a $50 car plus some extra work to make a battery pack that you can remove cells from.
    Doesn't look the bargain it did initially!

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