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Wall charger for rechargeable batteries HELP! Answered

Hi, I'm trying to figure out how to recharge these BATTERIES without having them blow up in my face. I'm very new to making my own electronics and a little timid when it comes to messing with batteries. I believe i need to use this DC jack connector? With this CHARGER? I'm using the battery to power 21 LEDS wired in parallel with resistors (3.4v 20mA) if relevant. I think i need to wire it up like in the picture.

I guess my question is if i wire all these things together and try to charge the battery will it destroy something?
Also if i wired two of these batteries in parallel can I still charge it the same way?
How do i know i'm using the right DC jack connector and charger?
Is there a specific switch i need to use?

Any help would be greatly appreciated!!!



5 years ago

Hi, thanks for the information. What i'm trying to do is make a LED
hula hoop. I've completed the project with regular batteries but i want
to make it so i can just plug the hoop into the wall to charge it
without removing the batteries.

THIS(https://www.instructables.com/id/21_LED_Rechargeable_Hula_Hoop/) person does something similar to the first picture I posted.

He uses a 6v charger with 4 x AA NIMH 1.2V rechargeable batteries wired in series. Is his method safe or risky?

You will need this charger to charge those batteries.

The charger is for 2 batteries. Pretty sure it will charge them in parallel.

Do you mean I can alter this charger to plug into a jack without having to actually put the batteries in the charger?

my goal is to make THIS(https://philihp.com/blog/2011/diy-led-hula-hoop/) hoop which i think alters the battery charger
like you advised? In this one he uses a Tenergy 32003 Protection Circuit

What is this thing? Can it be used to my advantage in a simple
rechargeable battery set-up?

Sorry for all the questions. I really appreciate all the help! :)


Reply 5 years ago

The protection circuit is for building custom battery packs. It's added protection to prevent over charging, over discharging and prevents too much current from being drawn form the batteries. It is not a charge controller and will not help to reduce the size of the charger.

Trying to integrate the charger into the hoop may be problematic. Your vary limited on space and it will through off the weight distribution.

Keep in mind NiMH batteries and Lithium at different beast when it comes to charging. NiMH are not as picky as lithium so it's easier to integrate the charger. NiMH may actually be safer in a hula hoop than lithium. They can take more of a beating even though it takes more of them and adds more weight. But with 4 batteries and enough wire you can spread them out around the hoop to distribute the weight.


5 years ago

mpilchfamily is right, you can't use that 5v power supply unit to charge you battery. Lithium ion batteries need to be charged quite carefully, they mustn't be charged to a voltage beyond ~4.2volts per cell and you need to limit the current during the charging process. Usually one just uses a Lithium Ion charger - they're all over the place. Otherwise you seem to be on track.


5 years ago

Yes it will destroy something. When dealing with lithium batteries you must have a charge controller. Go back and look at the page for the batteries. Take careful note of the WARNING in the description. You will need this charger to charge those batteries.


The charger is for 2 batteries. Pretty sure it will charge them in parallel. But since your a novice here you should redesign your light to allow the batteries to be removed so you can put them into the charger. Otherwise you have to try and modify the charger so your whole unit can plug in.

Other than that any switch will do. You'll have less than 500mA of current flowing through it.