New AC-DC Adapter or voltage converter?

[Quattro Pete]

I've got this ac/dc adapter/charger that expects a 240V input. My options are:

1. Find a similar ac/dc adapter that accepts 120V input. But how would I search for something like this online? I can find various 3.6V adapters on Amazon, but I don't know if the round plug would be the correct size/diameter. This adapter is used to charge a built-in (not easily removable) battery inside a toy. I'm not sure if the charging logic is built into this adapter or if it's inside the toy itself. Since it is 3.6V, I'm thinking this might be a Li-Ion battery (or maybe 3x1.2V NiMh batteries?) which requires special care when charging.

2. Buy a voltage transformer (from 120V to 240V) and just use this existing AC-DC adapter as is. This way, if the charging logic is built into this adapter, it would be preserved.

Thoughts?

 

[razel]

Good, UL rated AC/DC adapters start at $10 and up.

How sensitive is the device you're connecting this to? If not sensitive at all, you maybe able to get by with any 5v USB wall charger. Then splice that connector onto a USB cable.

Other options... 3.6v is the realm of LiOn batteries. It's also the realm of 3x1.2v rechargeable batteries.

 

[Quattro Pete]

Originally Posted By: razel
Other options... 3.6v is the realm of LiOn batteries. It's also the realm of 3x1.2v rechargeable batteries.

I know. I wish I could just pull out the battery and charge it in one of my standalone chargers, alas, there doesn't seem to be an easy way to get this battery out of the toy.

 

[pandus13]

Quottro Pete, i see your hair trouble did not ended, it seems?

i'm going to guess your in-laws/parents get the kids some european toys?

do you have in MI anything resembling the Devon ST strip in CHI? (indian/eastern/eastern european 220 power sources available.... convertors too 110V220V)
if not amazon linky-link and choose some with your Wattage at least (not the laptop ones, i melted a couple...) )

i know your pain: mine was: a combo kitchen food processors (wedding gift), mixer (same), lady "weed" trimmer (sentimental reasons --don't ask)

i just bought a 1,000W convertor and changed 2 resistance over the 8 years....

 

[Quattro Pete]

Originally Posted By: pandus13
if not amazon linky-link and choose some with your Wattage at least (not the laptop ones, i melted a couple...) )

Yes, I can buy a suitable voltage converter for about $16 from Amazon. A new ac-dc adapter would probably cost about the same, maybe a few bucks cheaper, but I don't even know how to find one with the exact same round plug. That's why I'm thinking I might just buy the voltage converter instead.

 

[pandus13]

Originally Posted By: Quattro Pete
I might just buy the voltage converter instead.


sorry, sometimes i talk TOO much! i was just suggesting to buy the voltage converter (step up/down) with adequate wattage.
like that you keep the same charger and not hunt down for whatever crazy plug size/form/output....

 

[redbone3]

This one looks suitable: http://www.all-battery.com/110VACto3.7VD...CFQ-1wAodOZkIEg Be sure to check polarity.

 

[Virtus_Probi]

If the label on that wall wart is telling the truth, the voltage is too low for Li-ion as those need to top off around 4.1 or 4.2V (unless there is a Boost in the toy, which is unlikely). I suspect it's for a different battery chemistry.

 

[EdwardC]

What's the toy? Maybe the instruction manual will give some insight into the battery chemistry. A lot of packaging nowadays requires lithium-ion battery labels.

If it's at all accessible, you could open the toy to check out the internals. Once you know how it's wired and the chemistry, you might be able to hack off the adapter's plug and use any other off the shelf battery charger you have.

 

[eljefino]

Could you just wire up a 220 outlet of that fine european pinout at or near your fusebox, and charge the gizmo there? Would that even be legal?

Or maybe wire one of these link and then make a little removable pigtail adapter.

 

[Quattro Pete]

Originally Posted By: EdwardC
What's the toy? Maybe the instruction manual will give some insight into the battery chemistry. A lot of packaging nowadays requires lithium-ion battery labels.

It's a remote controlled car. Text on the box says "Use 4.8V rechargeable battery (include)." It's a cheap Chinese toy with a ton of grammatical errors all over the packaging, so none of it can be trusted.

I decided to just buy a voltage transformer and use the supplied ac-dc adapter.

 

[Quattro Pete]

When plugged into the voltage transformer, the actual DC output voltage from this ac-dc adapter shows 6.2V on a multi-meter. That's double than what shows on the label.

 

[wrcsixeight]

Originally Posted By: Quattro Pete
When plugged into the voltage transformer, the actual DC output voltage from this ac-dc adapter shows 6.2V on a multi-meter. That's double than what shows on the label.


I have never seen a wall wart whose voltage unloaded, hooked only to a digital multimeter, matched the specs listed on the wall wart itself.

Unloaded DC voltage is always higher than spec, sometimes significantly so.

Charging of Lithium batteries requires more caution. Before I knew better, I used a charger which came with a budget flashlight, and that 18650 cell, which should never be charged higher than 4.2v, was at 4.67 volts, and I could not longer consider the cell safe for use.

With lithium battery charging, i always consider the 'what if....' and I place devices in an old saucepan or on a paver brick, and make sure nothing flammable is in the immediate area. but complacency is always a risk, as are cheap electronics when lithium batteries are involved.