Saturday, February 16, 2008

iRobot Roomba Charger for 220/240V Supply

You may be intending to buy (or have already bought) an iRobot from US for use in countries (like Europe, Australia/NZ or South East Asia) where the electrical outlet provides 220Volts or 240Volts. Using the given US charger on this outlets will definitely kill it instantly.

We all know why we would want to buy directly from US instead of getting it locally. Probably the model that we want are not available locally. But even if it's available, it may cost a bomb more than importing it yourself. But how can we actually use the imported iRobot on our local electrical supplies?

WARNINGS and Disclaimer

Before we begin please read the warnings and disclaimer!

1) Bringing the Roomba or Scooba for use out of USA/Canada voids the warranty.
2) The iRobot manual explicitly prohibits using of any power converter. Ignoring this warning voids your warranty.
3) Using any charger other than the provided original voids your warranty.
4) Any modification of the Roomba charger will also void your warranty.
5) As warned on the back of your charger, there is risk of electric shock if you open the charger. This electric shock can be fatal.
6) You should carry on the charger modification only if you are experienced in electronics. Otherwise, do not even try to open the charger casing!
7) Any mistake in the modification can lead to components EXPLODING & causing FIRE.
8) Electrolytic capacitors have polarity and will blow if placed wrongly.
9) If you insist to take the risk of modifying your charger, you will also be taking the responsibility for any problems that could arise.
10) The information provided below are for educational purposes only. Should you proceed with any of the options, we are not responsible for any damage arising from the use of this information.

So what are my options?

Basically, there are a few options, but please read the disclaimer before proceeding...

1) Buy an original charger for use on the 220V supply

I'm not sure how much your local dealer would charge for one of these, or whether they might even sell you one. But this would definitely be the safest option.

2) Use a transformer

A transformer, also called Power Converter or AC/AC Converter, changes the voltage of the supplies. Step-up transformers change a lower input voltage to a higher one, and a step-down transformer does the opposite. There are others which is able to do both step-up or step-down. What we are concerned here is the step-down transformer, changing the input voltage from 220V to 110V.

How to use the transformer? It's simple. Just plug it to your wall socket then plug the original iRobot charger to this transformer and you are done. :)

For the 500 series Roomba charger, it requires an input power of 33W. So we'd need to get a transformer that is rated minimum 35W.

However, it has been reported that a 35W transformer does not give enough power to fully charge the roomba, and the recommended rating is 70W to 100W. Be sure to get one that is industrial grade, otherwise your transformer would easily overheat and turn itself into a piece of junk. Mine did! :(

3) Use a universal power supply (UPS)

A universal power supply allows you to adjust the output voltage that you require. It usually has different sizes of output jack for you to plug into the various appliances. Some people use an adjustable laptop power supply. This is fine, because you'll just need the correct voltage and current to make it work.

For this option, simply replace the roomba charger (yes, you can keep it back into the box) with the universal power supply, shown on the right. So the UPS would connect to the home base. Since this is a replacement of the iRobot charger, the output voltage to the home base or roomba needs to be correct.

Let's look at our the charger specifications for Roomba 500 series. It says that the output voltage is 22.5VDC, and output current is 1.25A. So you'll need to do is to adjust the voltage on your UPS to about 22V and voila!

On some UPS, the output voltage is fixed. All you need to do in this case is to ensure that what you buy supplies a voltage of 22VDC and current of around 1.25A. There are cases of people using 22VCD with 1.6A current and there's no complains so far.

4) Mod your charger

This is the most dangerous of the few options available. Please read the disclaimer before proceeding. If you do not have any technical experience in electronics, please DO NOT try this option. A single mistake could cause your charger to blow into ashes. However, if you insist to take the risks and responsibility, continue reading...

The following describes how to mod the white Roomba 500 series charger (model 17062). Before beginning, remember to remove the charger from any power source, and ensure that the LED light on the charger is not lit.

What electronic components are needed for the mod?

We only need two electronic components for the mod.
1) 47uF 400V capacitor
2) Varistor rated between 270 to 380 volts (optional)

What to do?

First, to open up your charger you'll need to remove the white rubber studs under the charger. Removing them will reveal the screws.

After opening up the charger you'll see the charger circuitry. We are mainly concerned with 2 components in this mod. These are the C1 capacitor and the RV1 varistor.

We'll need to replace the capacitor C1. The original C1 capacitor (CapXon 47uF 200V) is rated at 200V and would blow if connected to the 220VAC socket.

Therefore, we'll need a capacitor that can cater to the 220V or even the 240V supplies. To find out the rating we really need, we use the following formula:

(AC RMS Voltage) x (sq root of 2) = 240 VAC x 1.414 = 339.4 V

Why do we need to multiply by square root of 2? If you study electrical and electronics, you'll know the reason. :)

So, having calculated the peak voltage of the AC current supply, we can find the right capacitor to use. We choose the 47uF 400V capacitor to give some extra voltage allowance in case there is a slight surge in the peak voltage.

Please remember to place the polarity of the capacitor correctly. Failure to do so might blow up your charger!

Usually we'll be getting the bigger version of the 400V capacitor, so before soldering, we need to ensure that there's enough room to place the capacitor. On the left, you can see a picture of how mine is placed. It's not advisable to leave the leads unprotected. I won't want them to touch each other and cause a short circuit, so I used a PVC tape to insulate each of the capacitor leads.

Once you are done with replacing C1, you can move on to the next step.

We need to replace or remove the blue RV1 varistor. The varistor is to protect the unit from power spikes. What it does is to conduct significantly increased current when the voltage becomes excessive.

The provided varistor is 10D271K. This is rated for a maximum VAC of 175V which is lower than our 220V or 240V supply. We will need one that is rated at least 270V in order to work on a 240V supplies.

If you cannot find a suitable varistor locally, you will just need to remove the varistor. It will still work this way, although there'll be one less level of protection for your charger.

Lastly, you'll need to change the power plug from the US 2-pin plug to your local 2 or 3-pin plug. Alternatively, you can get an adaptor for this, though the former method may be more convenient in the long run.

To summarise...
1) Proceed with the modification only if you have experience in electronics.
2) Replace C1 with 47uF 400V capacitor. Be careful of the polarity of the capacitor when doing this, any mistake can cause an explosion or fire.
3) Replace RV1 with a 270V and above varistor. Or simply remove it.

Testing the modded charger

Before you really plug the charger into the homebase or roomba, you should test the mod. Afterall, it's cheaper to get a new charger than to replace the entire roomba if anything goes wrong.

Screw back the charger casing, so that if anything blows (touch wood!), it's contained within the casing (hopefully...). Plug the charger to the power outlet and use a digital multimeter (DMM) to measure the voltage. It should read around 22.5VDC. If you try to read the current, the LED should blink and the readings would jump. This is normal.

Once everything is done, you are good to go!


Note: iRobot, Roomba and Scooba are the property of the respective trademark holders. None of the trademark holders listed here are affiliated with us.


welcometotheworld said...

I made this mod on my roomba charger a while ago - but now the led always blinks - whether it is charging or you have any idea how I can solve this problem - of course it means that the battery doesnt charge properly either...thanks - David

abecemod said...

Check your wirings and ensure that the cables are not shorted accidentally.

Alex said...

What part numbers are people ordering to do this mod in Australia? Anyone got them for JayCar?

/Richard said...


I did your mod and it works great!
To add to that is that I thought it was an ordinary switched power supply when I got it so I just pluged it in...and yes, I fried! =)
But by replacing the capacitor and the varistor and in addition the one that is called F1 just next to the varistor. Took this from another 230V switched power supply which I no longer used.

Everything works just fine now!
So thank You for you very good guide!
/Richard from Sweden.

Juan Pablo said...

Hi richard. I also fried my Roomba power unit because I connected to a 220v mains.
After inspecting it. Clearly the varistor exploded. But also it looks very dark burnt on the C4 and C20 capacitors near it.Also the IC chip (1200P60 CPDN) marked U1 in the PCB.
Maybe they werent affected.
Did your also looked very dark after the explosion?
Did you have to replace any of these?
I hope you see this.

/Richard said...

Hi Juan Pablo!

I only fried my varistor, my capacitor and the one called F1 (it is a small fuse).

It seems that your "fry" is more severe.

But begin with replacing the capacitor (the big one) and measure that your F1 fuse is not fried.
For initial testing you can just remove the varistor and run without it.

I found "spare parts" in another powersupply for an old router that I no longer used.

Be safe when you fiddle with this. I take no responibility for furter frying or injury.

Good Luck!

Juan Pablo said...

Thanks. Richard.
I should add that my C1 capacitor (the BIG one)was intact!
No burnt signal. No cracks. Nothing.
I will be careful. I know the risks.

abecemod said...

You can change F1 to a 1.6A 250V PCB fuse or pico fuse if you accidentally blew it.

Frebbin said...

Here's a question - does this make the mod a universal voltage adaptor? i.e. if I moved back, would I have to change the capacitor back?

Anonymous said...

Is the difference between the 50Hz vs 60Hz a problem?


Fofie said...

I moved in Australia with my roomba 400 series and I blew my charger.. :( I'm currently looking for a charger here in Australia that would work for my 400 roomba, but it seems that they don't have 400 series here.. My question is: Is the 500 charger (white) going to work with my roomba?
Thanks for your help!!

abecemod said...

Yes, the 500 series one is usable with the 400 series iRobot and vice versa.

badger said...


Thanks for the mod - worked just great. We know have one the 1st 530 Roombas in New Zealand!

thornstow said...

Does anyone know a brand name or part number for a UPS that meets the required specs.

I cannot find one with 22V.


Anonymous said...

Thank you for your mod, works perfectly.
One more thank you!

BK_man said...

Does anybody know a good silent model of capacitor? I got my Roomba 570 with already modified charger and noise is huge. I want to place Roomba's docking station under our bed so charger MUST be ABSOLUTELY silent.

I have Apple TV and disconnecting it's power cable every time before we're going to sleep.

Is it possible?

David said...

The charger shoukd not be noisy, perhaps the mod has not been done properly. Check that the capacitor and varistor have been changed, try removing the varistor, the charger should still work, but it will be more vulnerable to voltage spikes. Dont eletrocute yourself

Blogs Matchmaker said...

Hi abecemod,
After trying 50VA transformer my varistor blu up.
Does it mean that something else blu up as well? How to check and repare? Where to get a schematic with description?

Andre said...

Hi, first of all thanks for this guide, really good. And second, I have a question, if I were to use and universal power supply for laptops, with selectable voltage up to 22 volts but a corrent of 3.5 amp, would that work? Or would it blow my Roomba.
Thanks for your attention, hope you can respond.

Rego said...

Hi abecemod,

First of wall thank you very much for this detailed information on this subject.

I've bought one Roomba 561 in US and connected it on an European country... so it blowed the power supply.

Anyway I've changed the Fuse for a 2.0 250V , chnaged the Varistor also for a 391K and also the capacitor to a 47uF 450V.

Now the power supply charges the Irobot but... the blinking orange light is more quick on the blinking and actually doesn't ever stop even after 10 hours charging.

I've notice that the Roomba is charging but do you have any clue why doesn't stop charging and why does the light blinks faster.

Best Regards,

Martin said...

I made this mod yesterday and it works. Thanks for an idea and guide :-)
I replaced the original capacitor with new one - 47uF/400V, original varistor with metaloxid varistor 275Vrms and I replaced the original fuse with new one (1.6A/250V T) too.
Till yesterday I charged my three Roombas with universal chargers. There´re a 3800mAh batteries inside my Roombas and it lasted about four and half hour to charge it comletely. Now it takes two and half hour. That is really cool :-)

I´m going to try this mod for my scooba charger too.

The Diva said...

Hi Richard!

I bought Scooba in USA and sent it home to China when my mom plugged it directly in to a power strip and for 3 seconds, smoke was coming out... I don't know if it's burnt yet, but apparently the light was still blinking and it was still charging as this was happening.. They pulled it out right away and we are not sure what to do next. Should I ask her to take it to an electrician or just get an power converter directly? Thanks so much in advance!

Sharon said...

Just bought a scooba and just like the others, plugged it in any bang….
Anyway I was reading the MOD and I found that my power supply is a little different and was wondering if the same applies to me.
I have the L13143 scooba power supply which has 2 cap C1 and C2 (each 47uF 200V) do I need to change them both?

Jan said...

can you help me and recommend any on-line shop where I can buy this items and the international shipping will be free or very small? Can you recommend particular items (links) to these items?
Thanks for helping.

Lee said...

Hi Abecemod, my roomba bought from USA seems to have a problem charging even though we have bought a transformer.
Do you provide any repair svcs?


andre said...

Hi everyone, I have two things to say here. First, I recomend the modification provided by the moderator. I did it and my charger works great. It's been a year without any problems. It's easy to do if you follow the instructions and it's very cheap. Even if you don't know how to solder, just google it or check YouTube.
Second, I wanted to let you know that if you do this mod, I recomend connecting the charger to a surge protector or your robot may die do to some peak or short circuit in your home. I discovered the hard way that the robot itself has no fuse protection, I think the protection is in the charger, so when a friend came to visit and plugged a 110 volts hai dryer in my 220 volt home, guess what happened. The circuit of the robot died. I had to get a replacement robot from irobot. So use surge protection.

irobot said...

Hi! check out these irobot roomba 530, 540 and irobot scooba with 240v for use in Singapore at

Batel said...

I got my roomba 2 weeks ago from the US, but I'm using it with 220V, so I got a step-down transformer from 220V to 110V.
Every time I charge my roomba I'm getting "charging error no #5", Can you tell me if it is related to the step-down transformer or my roomba has some malfunction?
Thank you,

Blaz Gregorin said...


First of all I would like to compliment the site and confirm that the solution worked for me fine. :-)

But now I have a problem as a small part marked (1200P60 CPDN) marked U1 in the PCB blew up and I don't know what that part is so I can buy a new one and also if anything else might have been damaged in the process.

I would appreciate any kind of information and suggestions.

Thank you!

Feanor's Blog said...

Hello guys,

Some people asked some questions but noone get any replies.. But anyway I have a question too.

Yesterday till I realize that the adapter for 110V, I put it into plug and booom! it burned.

Now when I open it the blue thing (varistor) was blown up, so I bought an AC/AC converter (220V->110V) and wanted to remove varistor.

But there is no explanation, how can I remove that varistor? If I remove it then how will the circuit work? Maybe I should connect the 2 points from the back of the board together for it to be working?

Can someone quickly say something please? At the moment roomba says it needs to be charged, but I have no charger, and in the manual it says it's really bad to drain it's battery fully.


Keigo said...


Got a funny situation here.

My charger will charge the roomba fine with no error message or anything.

But once roomba fully charged. The charger green led will just blink and it will blink like 2~3 time then stop and then blink again.

No sign of error from roomba and when roomba go out cleaning and come back charging the charger green led will not blink and charge the roomba normally.

The blink only happen after fully charge the roomba.

hung_like_a_kiwi said...

I have just bought a 110v Scooba through Ebay to use in New Zealand, are the Scooba and Roomba chargers interchangable? or will I need to get a step down transformer for it?
Thanks for your help

Lauritz said...

Super thanks! Just what I needed!

barbernick said...

Hi, I have recently bought a scooba from the U.S I was wondering if my roomba charger (U.K voltage) would charge it? The spec for the U.K charger is,
Input100-240vac, 56/60 Hz0.68A
Input power 33W
Output 22.5, DC 1.25 A
If you could please advise, that would be great :-)

Emre Sezer said...


I have a universal charger of 22V (adjusted that way) and 1.6Amp. But gives Error 2.

Do you think it's because of high Amp? And I need to change my charger

Mibars said...

It also works with black slow charger: 20W, 120V 60 Hz, 0,75A output. It works great with 15 uF 400V capacitor instead of 33uF 200V one. Internals look the same. I guess that by replacing few elements one can mod slow charger into fast one.

Harris Anderson said...

Hi I am electrical engineering and I researching about electrical supplies for my school project. I found your post and it’s very informative. Thanks to your post.

Kimsa2211 said...

Hi there, iRobot team of dust-busting Roomba and its grime-fighting partner Scooba will effortlessly rid your home of filth. For detail information visit:

Sharon said...

Hi. Great blog. Extremely helpful. I am getting a US IRobot Scooba 450. Will I be able to use it in Israel by purchasing the battery charger piece there? Will the US Scooba fit into and charge in the foreign charger? I don't care if it voids the warranty, I just want to know if it would work. When I asked the chat person at IRobot if the US Scooba and the foreign Scooba are the same, he wouldn't say. Thanks.

Erico said...

Hello there... Was wondering what would the max voltage Roomba would take. I got ahold of a 24v 1.8A switched power supply (for a scanner, apparently) with the exact same connector. Would it be OK to use it?

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It becomes highly mandatory to go with the precautions and options to use the device safely. Transformers and UPS can do alot in this case. You can work on it more safely.
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