bishbosh Posted January 12, 2010 Share Posted January 12, 2010 I have a pair of Motorola T289 Talkabouts (late 90's vintage!) that I acquired in Canada and have been living in a box for about 10 years. The chargers for them are obviously 110V and although I have a large mains step down transformer, I want to get hold of a charger that ideally I can use in the car. So far I have had no joy with our friend Google, so can any of you electrickery gurus help me out? The charger has a fancy LED display on the back (totally unnecessary I am sure) and look like this.: Anyone point me at a 12V equivalent please? It is about time I started using the PMR's again! Yes I know I could buy new PMRs for little money, but what fun is that? Quote Link to comment Share on other sites More sharing options...
western Posted January 12, 2010 Share Posted January 12, 2010 the important bit is the output voltage/current of whatever charger you can find, it needs to be output of 4.2 volts DC 400Ma [milliamps] anything higher will just trash the transciever & the batteries, a lower output current would just mean the batts will take much longer to recharge. plus just so your well informed --- Check the frequencies comply with the UK freq's for PMR, if they don't you may need a PMR business licence to operate or run the risk of a OFCOM investigators visit. -- see attached page for the units frequencies & found a owners handbook here http://www.usersmanualguide.com/motorola/2-way_radio/t289 the UK PMR frequencies are There are eight 12.5 kHz simplex frequencies, which you may use anywhere in the UK. These frequencies have been harmonised (but not necessarily authorised) for use across Europe. The channel centre frequencies are: 1. 446.00625 MHz 2. 446.01875 MHz 3. 446.03125 MHz 4. 446.04375 MHz 5. 446.05625 MHz 6. 446.06875 MHz 7. 446.08125 MHz 8. 446.09375 MHz no licence required for equipment on these 8 frequencies. more info on UK PMR http://www.ofcom.org.uk/radiocomms/ifi/licensing/classes/business_radio/information/ofw57/ofw57.pdf Quote Link to comment Share on other sites More sharing options...
Ex Member Posted January 12, 2010 Share Posted January 12, 2010 If the charging circuits are in that device, then you are stuck using it. At 6 Watts any cheap 120V inverter would work in the car. $10 or so around here. Not sure what you do on the wrong side of the pond. eBay maybe. Here: http://cgi.ebay.co.uk/12v-DC-to-AC-adapter-Car-Power-Converter-INVERTER_W0QQitemZ380183527048QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item5884b43e88 Quote Link to comment Share on other sites More sharing options...
Robkav Posted January 12, 2010 Share Posted January 12, 2010 Maplins may have somethink Quote Link to comment Share on other sites More sharing options...
errol209 Posted January 13, 2010 Share Posted January 13, 2010 Maplins may have somethink Does Mr Bish's elastiktrikery skills run to finding out what voltages appear where using a multimeter? The plug has three poles (metal contacts) which is unusual. I think the one nearest the wire will be ground (0V), one will be the charger output and the third is possibly a sensor back to the charger control circuit (especially given the stern warning about battery types - it will be optimised for that particular battery's chardging characteristics. Three pole connectors on wall warts are quite unusual, so you may not find anything. Have you looked on Eblag and the like? Quote Link to comment Share on other sites More sharing options...
TheRecklessEngineer Posted January 13, 2010 Share Posted January 13, 2010 It looks to me like the charging circuitry itself is in the wall charger. The 3rd pole on the connector will be a temperature sensor of some sort. The easiest thing to do would be to buy a 110v inverter. I suspect the PSU inside is actually variable allowing the charging circuitry control the current into the batteries. From the size, I'd guess switched mode - with a bit of electrickery, you could 'fool' this into operating on 12vdc. I couldn't say whether it would work for sure though. I have a charger similar to this: eBay linky. I originally bought it to charge NiMH batteries for an electric skateboard. However, I use it now regularly to charge virtually any kind of battery. All it requires is a 10-14v input, and it will charge pretty much anything to a total voltage of around 24v (yes! from a 12v input.) Quote Link to comment Share on other sites More sharing options...
white90 Posted January 13, 2010 Share Posted January 13, 2010 I'd check the frequency range I had some from the USA Ian (AKA BBC) advised me the freq were illegal here so I binned them. Quote Link to comment Share on other sites More sharing options...
bishbosh Posted January 13, 2010 Author Share Posted January 13, 2010 Thanks folks. I have a 110V inverter that I can use in the house and I bought an ebay car inverter special - advertised as 110V - got it, used it, killed one of my chargers Closer inspection of the ebay listing shows the title as 110V but the text lower down (didn't read ) as 220V output . Anyhow, it would appear it is all academic as party pooper Ralph's link shows the frequencies to be naughty so I shall probably post them to a friend in Canada who can give them a home. Thanks all. Quote Link to comment Share on other sites More sharing options...
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