External laptop battery

[The Negotiator]

As a few of you know, I bought an external laptop battery. It acts like a PSU and plugs as normal into your PSU socket and basically charges the internal battery.

Sadly it broke my laptop (which would no longer accept power) which has just been fixed (i hope) and will be back Monday. Looking through the crappy manual, the diagram I used doesn't agree with the writing. I think I may have ****ed up and reversed the polarity...

Firstly you would hope it would have been protected from that and no damage would have occured, obviously not.

If I do a polarity check and also find the voltage is very similar to my PSU voltage, can anybody think of a reason why it shouldn' t work?

The battery is worth a lot, I really don't want to sell it as a) it would be dead useful to me and b) if it is more than the fact I mucked up the polarity, I wouldn't want to break somebody else's computer.

However, if I make sure the polarity is now correct and it damages my laptop AGAIN, Gericom won't repair it as they will know it was something I did! Maybe the best thing is to forget about it and throw it away, but like many of you here, that's the option which I would hate to do!

And yes, all this is very embarrassing

 

[JonnyBoy]

The laptop probably doesn't have polatiry protection as there is no reason for it to have it - all PSU's are pre-wired and therefore cannot be polarity-reversed.

I'm making the assumption that your external battery is a "universal" one where the polarity and voltage can be changed to suit various models of laptops - in which case it would be pretty easy to make a mistake and kill your laptops internal power supply circuit.

I would get a digital multimeter and test your starnard PSU, making a note of voltage and polarity, then test your external battery and ensure that it provides a similar voltage (within +/-5%) at the same polarity, boefre connecting it to the laptop again.

 

[The Negotiator]

Oh I will definitely do all of that, I am also testing it on a 24v 30watt bulb too. However, laptops do have polarity protection I believe, it blows a picofuse.

 

[NowIsGone1106]

its the amps you will need to watch...

alfie

 

[The Negotiator]

Alflie, the laptop charging circuit is what decides the amperage to be pulled out, current isn't forced in, voltage is.

To add to your comments Jonny, it is stupid (really) that they would design something without huge warnings about reverse polarity lol. They have a didoe and a nanofuse but Gericom have fixed it without problem - will find out what they swapped when it comes back, bet they changed the motherboard