I've got this idea in my head about cutting up a cell phone car charger and putting my own plug on it like one of these (instead of the cigarette lighter plug):

I would put a 1.5A fuse in it. Will this work without blowing up my phone?  Whenever I look at cell phone chargers I see this crap about IC chip protection.  1) do I need IC chip protection for a Li-Ion battery, and 2) if I do, am I cutting it out when I cut the cigarette lighter plug off?

I did a little bit of my own research online and it appears that a Li-Ion battery is set up to protect itself, so I should be safe in what I'm doing, but I would like some confirmation from someone who knows more about this stuff than I do.

I have a car charger for my cell phone.  The plug which goes into the cigarette lighter has a long body (maybe 4.5"), which is so long that I bump it when shifting the transmission.  I asked the vendor if I could replace the plug with my own (fused) cigarette lighter plug, and I got the same story: the charger is a "smart" charger, and the "smarts" are in that plug.

My cell phone has a 3.6v battery, and the AC-powered charger provides 4.5v DC.  I also have a car charger.  I suspect that either the car charger cable adjusts the voltage down from 12v to below 5v, or else the phone itself is able to handle 12v on the charging pins.  My bet is on the charger cable.

DO NOT wire your battery straight to the 12V supply without checking to see if the phone takes 12V.  The circuitry IS in the charger plug. LiIo batteries will get super hot to the point of ignition if mishandled. Now it may be possible that your phone can handle 12V, but not likely.

Is your problem like Rema's and the plug is too big/long? If so, buy/make and extention cable that has a shorter plug on it that moves the long one out of the way. Of course then you have an even longer lump with the socket/plug combo.

To be sure, the sellers of this stuff do not consider how cumbersome some of the designs are. Apple should design stuff for the cell phone industry. They have some really sweet ergonometrics.

This idea was just to make fewer adapters/extensions to plug my cell phone in for charging on my bike, nothing that's very important.  I guess I'll just put this project on the backburner, maybe I'll tear apart a car charger someday when I don't need it anymore.  I was under the impression that my battery might have built in protections to convert 12V down to 3 or 4 volts, whatever it actually needs.  I don't want to do anything stupid to the battery though.

Quote from: manofthefieldThis idea was just to make fewer adapters/extensions to plug my cell phone in for charging on my bike, nothing that's very important....

Ooooh! Why didn't you say so in the first place? Have you seen Kerry's post on adding a car type outlet to the GS here?

His a pretty good way to do it and already written up. Either one of us can help you with this.

Yup, I saw that, in fact I already did that with my own twist, I was just thinking about how to do it another way.  Here's what I did.

Ah so! Very good adaptation.  Looking back at the top of this post....

QuoteI've got this idea in my head about cutting up a cell phone car charger and putting my own plug on it like one of these (instead of the cigarette lighter plug)

...it would seem that you are just trying to get a cleaner connection than the lumpy 12V stuff.

That 's more understandable. You are still stuck with a circuit to handle the battery management regardless of the wiring or connectors. You could buy another 12V adaptor identical to the phone unit and repackage it. I call this a plumbing problem. No real electronics involved.

oldest thread here i can find. sweet!

Does that make me old now

Er...mmm...uh...how bout we go with more seasoned rather than old eh? 

Are we bored today?

Mary

Quote from: jserio on January 31, 2011, 08:36:09 PM
Er...mmm...uh...how bout we go with more seasoned rather than old eh? 

locate the pablo photochop thread. or hell maybe i have to start another one