Power Supply from Laptop for Lipo charger

ARGH! Darn windows/unix file naming...to url...here they are...

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| I have an Electrifly PolyCharge charger for my batteries. It takes | 11-15VDC input and I have only used it once (using my car battery). I | came across an old laptop power supply at work and decided to tinker | with it tonight. It outputs 16VDC (measured to be 16.45VDC) but I | think that it should be fine.

It might work, but I wouldn't risk it.

If something says 12 volts, I wouldn't give it more than 14 volts, since 13.8 volts is about the maximum that it'll see in a car. 16 volts is asking for trouble ...

I've got a 12 volt power supply in my closet. Used to be my mother's. We used it for testing things like car stereos. Well, we tested a stereo, and it worked, and then it stopped working. Huh? So we tried another. It worked, and then it stopped working, and smoke came out ...

... turns out the power supply was putting out about 16 volts if I remember correctly.

Really, I should either figure out what's wrong with it and fix it, or throw it out. Or at least put a big sticker on it that says PUTS OUT TOO MUCH VOLTAGE! DO NOT USE! Otherwise, it may eventually eat more car stereos or something ...

| We will see if my free power supply | costs me $20 to replace the Electrifly. Here are some photos I took | of the process. Just tinkering...

Looks like you did a nice job, but I'd not suggest actually using it unless you can adjust the voltage on your power supply ...

If I may suggest, read some of the comments in the link below on LiPo charging before you plug your Batteries into your new charger setup. That way you will be making a more informed decision. Just a suggestion.

Have a nice day.

Make a quick call to your insurance agent as well to be sure fire coverage is up to date. :o)

Charlie

Note that those nicad chargers are meant to be plugged into a car battery. Automotive systems are notorious for horrible regulation, with spikes up to 100V. Thus, if the charger doesn't have some kind of overvoltage protection, it's probably not long for this world anyway. They way they work suggests to me that they will not have a problem with higher voltages; they'll just dissipate a bit more power in the charger, and get a bit hotter.

Another solution for the high current nicad charger, however, is a little jumpstart battery. You can get them really cheap, and they also come in handy if your car battery dies.

I sent an e-mail to electronic support at hobbico with my question. Their reply was as expected. The 16V power supply will work just fine. Just to be clear, I am using this 16V power supply to provide source power for the ElectriFly PolyCharger

Carl

Whoops I must admit I did not read your original post properly!!!!

Yes, it should not be a problem.

Good luck and have a good day.

Les

You will likely be fine. Remeber that under no load, most powe

supplies will deliver higher voltage than they indicate, when loade they drop.

Mik

-- pda4yo

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| You will likely be fine. Remeber that under no load, most power | supplies will deliver higher voltage than they indicate, when loaded | they drop.

This is absolutely true of a wal-wart, where you just have a transformer, a resistor and a diode (or maybe four diodes). The difference is often quite large.

However, it's not so true of switching power supplies, and most laptop power supplies are of the switching sort. (And so is his, judging from the `open' picture he gave us.)

In that case, the voltage will drop when you put a load on it, but only a little. I'm not saying you're wrong, only that the effect is small enough to be mostly ignored as long as you don't overload the power supply.

If the manufacturer says that 16 volts is fine, that's fine, but I certainly wouldn't assume that other devices would work with that.

True very true..... You are right this is a switching supply and the stay quite constant.

Mik

-- pda4yo

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