Converting a charger from 240V AC to 110V AC

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1

Hello all.

After completing one of my projects to run my 24V video lights from tool battery banks, I am left with a few spare battery charger PCBs.

I sometimes travel for work to countries that run 110V AC. One of the things I noticed is that tool battery chargers are still designed in a dumb way where they can’t take 110V-240V like most mobile phone chargers, camera chargers and even laptop chargers.

There has been quite a few instances that I can find online where people has made the conversion for their chargers bought abroad to 240V. Mostly because they are cheaper there.

If you google 110V to 240V charger conversion you will see that Makita, Dewalt, Milwaukee and Ryobi chargers have been converted by replacing some components in the PCB, mainly a varistor, a capacitor and in some cases a mosfet.

Because the chargers that I was left with are from Aldi. I can’t find an equivalent in 110V. The most similar one is the one from Bauer Hypermax tools in the USA but that charger has more poles and in a photo that I saw of their batteries they also seem to be wired differently to the ones for Aldi.

My question is. Can someone with knowledge in electronics have a look at the photos of my charger PCB units and see if there is a possibility to convert them to run on 110V AC?

They seem to have been designed to support 50/60Hz so frequency would not be an issue.

It would just be so much easier and efficient to carry just chargers converted than to have to take a step-up or a 110V AC to 12V DC convertor and a 12V DC to 240V AC invertor just for the sake of charging batteries.

The two versions of PCB chargers I have are in the following link.

https://imgur.com/a/FfGdeoM

For what I can see the first varistor is a NTC 10D-7 in one of the boards. The other has a NTC 5D-9, then a 275V Capacitor (the yellow brick). The big black capacitor is a 400V 47uf. The mosfet is a SVF7N65F SW7T22B.

Thanks

2

Have you had a look at what the output voltage is if you put 110v in? Because the frequency is the same worst case you will get a low voltage out, best case it will have been built to still output the same voltage.

3

Clinton.

I did find a ac-ac step down. Connected one of the chargers and the output is the same as if it was connected on 240V. But I need to put a battery on charge to see if it takes the same time.

Thanks for that suggestion.

4

Not a problem, I think the charge time would remain the same the limit on charging current is usually in the batteries.

5

I was thinking if the Amps would remain the same.

6

Power should remain constant and P=IV, so at 110V you get about 20A (minus losses from the converter) from a 240V, 10A (2400W) source (as long as the converter can deal with that power level).