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Thread ID: 33274	2003-05-12 08:10:00	OT: battery chargers	bmason (508)	Press F1

Post ID	Timestamp	Content	User
143476	2003-05-12 08:10:00	hi all. I'm getting a bit off topic here but I know there are a few people know a lot about this stuff. I've been given an old Alcatel 305 mobile. The only problem is I don't have a charger for it. I can't find one second hand and Dick Smith want $60 for a new one (cat E0427). The phone uses a standard 1.3mm dc plug so I don't see why I can't use a normal AC adaptor, which only cost ~$30 new. Is there any actual difference between the charger and a normal AC adaptor?	bmason (508)
143477	2003-05-12 08:25:00	Yes, there is a difference. The correct charger would have a form of current limiting to prevent the battery from damage. In some cases its built into the phone itself, but often not. The voltage is quite critical as well. Not familiar with the model, is that one where you can use 3 x AAA cells for power, instead of the rechargeable battery?	godfather (25)
143478	2003-05-12 10:03:00	> Not familiar with the model, is that one where you > can use 3 x AAA cells for power, instead of the > rechargeable battery? I don't know if the 305 was ever sold here. The phone is from oz. It was the alcatel DB that could run on AAAs. It still uses 3 AAA rechargeables but they have a plastic casing around them. Check out DSE cat. E2224 for a pic. I tried the db's charger BTW, the phone didn't seem to like its 12v (would only start charging just after I turned it off at the wall). I guess plan B is finding a 2nd hand charger at the right voltage and replacing the connector. I have a phillips 4.2v which I will try. If any one knows the output voltage and current of an alcatel 300 series charger I would love to know. The DSE one is kind of vague. Interestingly they sell the same charger for use with alcatel DBs when the origional one puts out 12v.	bmason (508)
143479	2003-05-12 10:25:00	If its using 3x nicads/NiMh batteries, then obviously the terminal voltage is 3.6 nominal. Thats also the voltage of most Nokia 5xxx and 6xxx series batteries as well. 12 Volts would be a killer, but the current limiting is the issue, with correctly rated components it will require a higher voltage to give a more constant current. My Nokia has a 3.6 v LiIon battery, but two separate generic chargers have outputs of 6.8v 700 mA. Try one around these figures, but I can tell you that a "normal" plugpack will seldom work, I think the current limiting is very important and it would be easy to fry the battery and/or phone when not using the correct charger. You may be able to get your hands on a car charger, they are cheap and you could feed the electronics from your 12v plugpack, the electronics in the car charger should interpose OK.	godfather (25)
143480	2003-05-13 02:11:00	You might find a proper charger at Cash Converters or a weekend market, for $5-$10 . Otherwise, you won't hurt the battery if you charge it at 1/10th of its mAh rating (probably about 70 mA) . You could probably go higher . But you do need to limit the current .	Graham L (2)
143481	2003-05-13 02:12:00	Try Cash Converters, they often have a bin of second hand chargers available. I wouldn't just use a normal plug pack as the cost of a new battery is probably more than that of a new charger. Look on online auctions like trademe (http://www.trademe.co.nz) for another option. G P	Graham Petrie (449)
143482	2003-05-13 07:06:00	I had a look at cash converters . My phone seems to be too recent for any to show up . They did have a whole pile of alcatel db chargers . The interesting thing is the db uses the same battery as the 300 series . 3 AAA nimh batteries . The only difference is the shape of the plastic holding them together . Yet the DBs charge off 12v . A friend of a friend has an origional charger so I might find out the correct voltage . So Plan C is: Grab a DB charger for $15 and use a resistor to drop the voltage until it starts charging . If I kill the battery I should be able to replace it for $15 if I can get the plastic packaging apart . And in the worst case, the phone didn't cost me anything and the origional owner is too rich to care .	bmason (508)
143483	2003-05-13 07:22:00	The open circuit voltage (12v) may be irrelevant if the charger contains the required current limiting. At the rated current, the voltage may be correct. The Nokia battery (3.6v) uses a 6.8v charger, which is current limited at 700 mA. When it reaches this current the voltage drops. The phone monitors the battery voltage and detects a fully charges state (by the small voltage variation that occurs) and switches into a trickle charge state. This is what I was trying to convey, and why you cannot usually use a normal 12v plug-pack, as there is no current limiting and the phone will probably have protection built into it to prevent it charging outside the parameters it can tolerate.	godfather (25)
143484	2003-05-14 02:26:00	My suggestion was based on the "14 hour" charge, which should be safe on any NiCd or NiMH battery . BTW: Do not use anything but the proper charger for a Lithium Ion battery . They can explode and/or have serious consequences if they are electrically maltreated . :D	Graham L (2)
143485	2003-05-14 03:14:00	> BTW: Do not use anything but the proper charger for > a Lithium Ion battery. They can explode > and/or have serious consequences if they are > electrically maltreated. :D So a Lithium ion charger will work with ni-mh batteries? I thought L-ion was a different type. Unless something else comes up my choice is between a phillips 4.2v 770mA 3.23VA(?) charger (from a savvy IIRC) and a modified alcatel DB charger. I figured the DB charger would be better because it charges the same type of battery (I don't know what the phillips is designed for). I'm assuming its the 12v the phone doesn't like because it will start charging just after the charger is switched off. The DB charger is only 500ma which shouldn't be too high. BTW, going by appearance it might actually be a 310 if thats relevant.	bmason (508)
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