12v to 5v transformer/charger options?

[VAL. H.]

I have a little problem. I need to be able to charge my Midland BT2 headsets via the bike whilst on hols.

(Midland are unable to supply 12v chargers for the time being)

The BT2's are charged via a mini USB port in the dongle. They are 5.5v 0.4A

What I'd like to get hold of is a cig lighter plug/socket 12v - 5.5v transformer of sorts that I can plug in, or wire to the bike.

I already have a cig type plug/multi socket witch also incorporates USB sockets. I also have a USB to mini USB lead I can plug into the dongle. So if I can get the above 12v - 5.5v adapter I'll be ok.

Anyone know where I might get one such thing?



Alternatively:
There is the option to use a small low power out-put (75W) inverter.

Question:
Is something like this going to be ok to use while the bike is not running?, bearing in mind the expected current drain is 5.5v at 0.4A. Charge time is 4hrs.
Will the battery survive this kind of drain on a daily basis over a two week period? My thinking being that inverters are inherently inefficient.


Any advice please?


Val.

 

[Timpo]

PM sent.

 

[stonetown]

Can you send me a PM also, I'd like to hear suggestions on this one?

PM sent.

 

[Doofus]

Hi

I am not sure where you are getting the 5.5 volt number from - presumably from the mains charger?

Either way, the USB sockets on your "cig type plug/multi socket incorporating USB sockets" will nominally be 5v, as that is the standard. So, if you plug your cig-type plug into a 12v socket (you might need a bmw plug to "normal" socket adapter), and plug your USB-to-miniUSB cable into the USB socket, you will get 5v at the end of the miniUSB.

I suspect that will work fine at charging your headset.

In practice the 5v on your miniUSB will more likely be around 5.2v (from my experience). The rechargeable battery in your headet will probably only charge to around 4.7v anyway.

If I was you I'd jut try with what you have - it would be spectacularly remis of the manufactures if the USB sockets on your cig-plug adapter were not 5v, but to be sure you can charge your headset from the USB standard 5v, instead of your 5.5v, you cant first try with your usb-minUSB cable from your computer's USB port first.

Also even if the headset initially draws 0.4amp when fcompletely flat, it will soon reduce. You need a new battery if you can't charge a tiny headset once a day!

good luck

 

[VAL. H.]

Hi

I am not sure where you are getting the 5.5 volt number from - presumably from the mains charger?

Either way, the USB sockets on your "cig type plug/multi socket incorporating USB sockets" will nominally be 5v, as that is the standard. So, if you plug your cig-type plug into a 12v socket (you might need a bmw plug to "normal" socket adapter), and plug your USB-to-miniUSB cable into the USB socket, you will get 5v at the end of the miniUSB.

I suspect that will work fine at charging your headset.

In practice the 5v on your miniUSB will more likely be around 5.2v (from my experience). The rechargeable battery in your headet will probably only charge to around 4.7v anyway.

If I was you I'd jut try with what you have - it would be spectacularly remis of the manufactures if the USB sockets on your cig-plug adapter were not 5v, but to be sure you can charge your headset from the USB standard 5v, instead of your 5.5v, you cant first try with your usb-minUSB cable from your computer's USB port first.

Also even if the headset initially draws 0.4amp when fcompletely flat, it will soon reduce. You need a new battery if you can't charge a tiny headset once a day!

good luck

Your right there, new battery being couriered to me tomorrow (thanks NOG ) almost got stranded this morning.

I was wondering if there was some sort of standardization for the voltage out put of USBs, but never read anything anywhere


Well your absolutely right, I just had a rummage and found I have all the necessary leads to charge them from the USB lighter accessory plug. Looks like I may even be able to charge them on the go whilst using them too.

Thanks for your Help Daz, and everyone else too

Cheers guys

Val.

 

[stonetown]

So, I've got a 300W inverter and want to charge my laptop whilst on the move, the max draw listed on the laptop PSU is around 100W, it might be less when charging. With the 08 GSA alternator producing 720W should this be enough to charge the lappy using the inverter? What do cars generate?

 

[theEnglishman]

300W at 12 volts??? Thats 25 amps Do you really mean that???

Much more likely is a 1A charger - Maplin do a circuit board for a tenner that'll need soldering and putting in a case.

http://www.maplin.co.uk/Module.aspx?TabID=1&ModuleNo=3488&doy=19m8

Or pay someone a number of beer tokens to make it for you

 

[Doofus]

Hi

you cant first try with your usb-minUSB cable from your computer's USB port first.

Val - glad my typo ("can" coming out "cant" didn't throw you too much).

For powering a laptop from 12v I got one of these...

http://cgi.ebay.co.uk/100W-CAR-UNIV...39:1|66:2|65:12|240:1318&_trksid=p3286.c0.m14

Although mine came from a different seller, it looks identical - works a treat and not a bad price.

 

[twisticles]

Powerlet is your friend:

 

[Kritou]

Val - glad my typo ("can" coming out "cant" didn't throw you too much).

For powering a laptop from 12v I got one of these...

http://cgi.ebay.co.uk/100W-CAR-UNIV...39:1|66:2|65:12|240:1318&_trksid=p3286.c0.m14

Although mine came from a different seller, it looks identical - works a treat and not a bad price.

After reading your post I also ordered one from the same source. It has just arrived and looks good but can't figure out how to change the polarity from centre plus to centre minus - any ideas?