Charging CCTV li-ions via 5v USB

fraction · 29th September 2011, 04:51 PM

Quick (possibly stupid) question regarding those cctv li-ions you can get on ebay.

Some have a 5v USB out as well as the 12v normal out. Can you charge via the 5v port?

I know it's a long shot but I'm wondering if anyone knows.

Saturnus · 29th September 2011, 05:38 PM

No. It's an output.

fraction · 29th September 2011, 06:09 PM

Dammit, that's what I thought. Im trying to rig up some way of charging my boombox without removing the battery or opening it up.

fraction · 3rd October 2011, 08:27 AM

Does anyone know how I could rig this up. 5v usb input that will charge a 12v battery, lead acid or li-ion.

Saturnus · 3rd October 2011, 08:41 AM

USB power is +5V and 900mA (for version 2 or newer, and 500mA for version 1.1 or older), that's 4.5W output max. Even if we assume 90% charger efficiency that's only 4W. With a 12V 7Ah battery, that means a full recharge would take over 60 hours.

In other words, it's possible but it's not realistically something you'd wanna do.

fraction · 3rd October 2011, 09:05 AM

Ah, ok. Cheers saturnus.

fraction · 12:51 PM

Ok, on a related note, if I

1) mount a 2.5 power jack on the outside of my boombox
2) link this to a lead acid
3) link the lead acid to the amp
4) plugged a 13.5v 1A power supply into the external power jack

Then everything should work, shouldn't it?

The battery will charge (although slowly towards the end of the cycle) and won't be damaged (13.5v is float voltage). Amp will draw power from the supply if present, battery if not (well, sort of). I'll be able to plug it in and unplug it at will. Or am I missing something here?

I was thinking something like this:
AC Power Adapter For Sony Camera EVI-D30 13.5V 1A New | eBay

or this:
http://www.cableuniverse.co.uk/switc...-3a-13.8v.html

(cheers for your continued help btw)

29th September 2011, 04:51 PM	#1
$fraction is offline$ fraction diyAudio Member Join Date: Apr 2011	Charging CCTV li-ions via 5v USB Quick (possibly stupid) question regarding those cctv li-ions you can get on ebay. Some have a 5v USB out as well as the 12v normal out. Can you charge via the 5v port? I know it's a long shot but I'm wondering if anyone knows.

3rd October 2011, 12:33 PM	#7
$fraction is offline$ fraction diyAudio Member Join Date: Apr 2011	Ok, on a related note, if I 1) mount a 2.5 power jack on the outside of my boombox 2) link this to a lead acid 3) link the lead acid to the amp 4) plugged a 13.5v 1A power supply into the external power jack Then everything should work, shouldn't it? The battery will charge (although slowly towards the end of the cycle) and won't be damaged (13.5v is float voltage). Amp will draw power from the supply if present, battery if not (well, sort of). I'll be able to plug it in and unplug it at will. Or am I missing something here? I was thinking something like this: AC Power Adapter For Sony Camera EVI-D30 13.5V 1A New \| eBay or this: http://www.cableuniverse.co.uk/switc...-3a-13.8v.html (cheers for your continued help btw) Last edited by fraction; 3rd October 2011 at 12:51 PM.

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29th September 2011, 05:38 PM	#2
Saturnus diyAudio Member Join Date: Jun 2005 Location: Copenhagen, Denmark	No. It's an output.

29th September 2011, 06:09 PM	#3
$fraction is offline$ fraction diyAudio Member Join Date: Apr 2011	Dammit, that's what I thought. Im trying to rig up some way of charging my boombox without removing the battery or opening it up.

3rd October 2011, 08:27 AM	#4
$fraction is offline$ fraction diyAudio Member Join Date: Apr 2011	Does anyone know how I could rig this up. 5v usb input that will charge a 12v battery, lead acid or li-ion.

3rd October 2011, 08:41 AM	#5
Saturnus diyAudio Member Join Date: Jun 2005 Location: Copenhagen, Denmark	USB power is +5V and 900mA (for version 2 or newer, and 500mA for version 1.1 or older), that's 4.5W output max. Even if we assume 90% charger efficiency that's only 4W. With a 12V 7Ah battery, that means a full recharge would take over 60 hours. In other words, it's possible but it's not realistically something you'd wanna do.

3rd October 2011, 09:05 AM	#6
$fraction is offline$ fraction diyAudio Member Join Date: Apr 2011	Ah, ok. Cheers saturnus.

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