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Exactly what components do i need to charge a bank of our four (or however many it takes!) 18650 batteries {we will be using a dynamo} with an LED to show that the batteries are being charged ? Answered

(if needed ?)Hello & Good day to you all,

Me and a friend have plans to build a miniaturized 'Rolling Road' platform for our RC 1/10th scale nitro cars!!

What we both agreed on is that the Rolling Road platform is to be made out of acrylic and using skateboard bearings and other hardware, but we are completely stuck, we have an idea to add lights to the platform, the kind of cold-cathode tube lights that are for inside-pc-use...

We want the tube lights to run from a rechargeable battery bank from the Rolling Road but incorporate a charging system "built-in" to the platform and a system based on renewable energy because as our cars are nitro powered, they will be turning the rollers of the platform for many hundreds of thousands of times and we wanted to harness that mechanical energy to charge the battery bank - in turn to operate the tube lights!

We are both ok the structural aspect of building this rolling road platform but dont know where to start on fabricating an electronic set of components culminating into a sustaining system that produces (almost) free energy!

The system must be able to run 4 sets of these tube lights, each tube light set is comprised of 2 tube lights each, so 8 tube lights in total ! The tube lights are rated at 12 volts.

What our dreams are : (lol)

- The system must collect the electric being made to charge a battery bank,
- The system must have an LED 1 to only show the battery bank bank is being charged,
- The system must have an LED 2 to show that the battery bank is fully charged,
- ALSO ! if at all possible, include a simple row of 6 or 7 LED's (LED BANK?) to indicate how full/empty the battery-bank is &
- Lastly, there must be a switch to switch off the circuit that charges the battery bank (when batteries are fully charged !)

Ingredients: (what we DO have, lol)

20 x 18650 batteries
Plenty of spare motors
Lots of different grades of wire
soldering skills
a few switches
10 Pairs of 12v PC Tube lights (Both 4" & 12" )
Small to medium range of "ON Semiconductors" (Voltage Regulators) Max Input Voltage is 40v of one of these!

What we dont have:

- Knowledge of electronics!
- LED's
- Capacitors (if needed ?)
- Resistors (if needed ?)
- Transistors (if needed ?)
- Semiconductors (if needed ?)
- Diodes (if needed ?)
- Help !

Please please please could anyone help us to even roughly 'sketch' a set of components that we could solder together, lol, a Circuit, lol x2!, so we can start ordering the needed items to enable us to make this miracle happen ?!!?

But to make it idiot-proof (dumb-it-right-down for us!) and extremely simple circuit diagram, not the actual way you geniuses write em, if say to draw a semiconductor, i would draw a square then draw 3 lines coming out the bottom of it to show the legs of it!

We were only-just able to follow the circuit diagram HERE - ONLY BECAUSE there was a picture of exactly how the circuit looked, in-real-life! So we followed the wires exactly to make the solder fume extractor but were only able to, again, because of the pics! please help! i feel like crying! lol !

We have both spent a few years trying to read electrical diagrams and we get lost very easily ! Is there even a way to dumb it down for us ???

Is there any hope ?!!?

A very-Many thanks in advance to all for reading this and even more for any help received !!!!


C'mon, it really is easy to start understanding schematics if you can follow your own diagrams. Just look at it like your mechanical plans but instead of screw connections - wires go there.

That said, you should start out with the basics of finding out what the voltage(volts) and power requirements(dc/ac, watts/amps/milliamps) of your components(how many batteries hooked up in series or parallel, tube lights, LEDs, motors, etc. With that info you can plan to get a charging circuit that is up to snuff and to see if your dynamo is even capable of doing the charging. Good luck.

At the moment im trying to track down the ingredients for making a simple H-Bridge (from this great looking instructable!) but i am getting no-where in finding what i need to buy, every uk website selling singular components dont seem to have anything i need as per the shopping list in the above link !!!!

I made an instrucable here for a dual direction liquid pump (internal 'Guts' are complete, making the housing as we read this) and that H-Bridge would have come in right-handiness there bcoz i could have used only one 9volt battery but ive had to use two 9volt batteries & wire up 2 separate wiring loops to reverse the direction of the motor!

Im having major problems on just that alone so the thing is, if i cant even find and order the components, then how am i ever going to make what i need in this post ive asked the help on !!! Know where im coming from ?!?

I need showing, kinda, but am a quick-study, learn quick but it just takes someone showing me !

But the H-Bridge instructable is all there, ingredients and-all - and im having real difficulties there !!!

can anyone help an almost lost-cause ?!!?


Yelp-for-Help !!!

There's no need to use fancy relays, just use ordinary ones.
Maplin has plenty


Thanks Steve, but i tend not to get anything from maplins as they have too much of a 'mark-up' on the most basic of electronic components, i usually try to find online retailers that supply their components without the increase in price as im severely mobility impaired and-so on a very tight budget !

Thanks for pointing me in the right direction tho !


Thanks again steveastrouk & Yes that is true, i have had-to grab a few items from maplin as no one else was selling what i needed so maplin has the monopoly in the uk for certain items....

Unfortunately for me i may have been asking for way-way-too-much for this project in all its Grandeur as im only just learning electronics and fear i have asked for help on a gargantuan project!

I think i'll need to break this down into six or maybe even eight separate circuits to be intertwined onto one, far beyond my skill as i do not have a working knowledge of electronics!

Its a shame i wont be able to make this happen until i know what im doing (which will probably take all year!)


Thanks again for the advice!

RS and Farnell will sell on-line if you need parts. In fact, if you live closely enough, you can even collect from their tradecounter.

Many thanks for the reply!

Ive really tried to learn how to read the circuit diagrams and have over 100 webpages bookmarked from google searches but am totally lost on where to begin!

All i know for certain is that i have 20 18650 batteries (they are 3.6volt and discharge at 5000mAh) and, um, well whats the best way to put them into a battery bank, like, is putting them in serial better than parallel for how i intend to use them ?

And when i have them in either series or parallel (bank/power-pack) - i know that they let-go of their power as 5000mA per hour, so what equations or calculations do i use to find out what kind of power rating the motor i will be using must be in order to efficiently charge up the battery bank ???

I think i might cry, lol

1. slow down, you are trying to do a lot of things that you should do separately to get experience before you move on to the next step.

Build your rolling platform and get that working.

Power up your lights to see that they work off of a wall-wart/transformer(your link says that someone ran them off of 12volts DC)

You have a bunch of Lithium ion rechargeable batteries. You can group them to get 12v but you would want a multimeter to check the output to and know what voltage tolerance you want before you blow out the lights. Lithium ion has its own problems that you need a proper circuit to discharge and recharge the batteries or else they may heat up and pose a danger. Nickel metal hydride - regular rechargeable batteries - the more common ones have simpler concerns.

Working with a dynamo has its own complexities.

All-in-all, you may need more help than I am knowlegeable of.

Again, i am most grateful for your advice !

lol @ slow-down!

Yaa, that'll be my biggest problem, trying to run before i can walk!

Would you be able to suggest any kind of beginner instructable/s that i could build, out of the extremely common components found in an online components shop please please ?!?

i have ordered myself a simple beginners breadboard kit, just have to wait for that to be delivered, also i have started to test batteries for their voltage with a multimeter - also most of the forums ive read keep saying that i need a special battery-voltage tester that a multimeter alone wont do ???!!!???

Goog-Grief ! this is a headache for me but what can i do, i really want to make these things !

i have an Electronics for Dummies book on the way too, just wish i paid-more attention at school !

again many thanks in advance for any help graciously given !!!