ICOM lithium ion battery charger DIY help

[shakezilla]

Hello,
I am new to the forum, and would like to reach out with a newb question for some of the more experienced members.

I have a ICOM VHF emergency radio, with a lithium ion battery (BP 252). The issue I'm having is with charging the battery pack. About a year ago, I lost the desktop charger that came with the device. Ideally, I would like to avoid paying $50 for a new charger, and have a way to charger the battery with a solar panel or USB port if needed in an emergency. The battery has 3 prongs at the base, labeled (+), (-), and a B in the center.

I have tried to simply connect the (+) and (-) with a lower output USB smartphone charger, but the circuit is not being completed (as I'm sure a more experienced person would expect). Admittedly, I always avoided electrical engineering in physics like the plague, and now I'm kicking myself for it.

As I said, this may be a total newb question. However, I have found ZERO information about charging these types of batteries online. If someone could shed some light on my situation I would be very grateful.

I have attached a link to a similar replacement battery for reference.

 

[itsmoked]

Do you understand that if you over-charge or over-discharge a lithium battery it will catch fire? This puts your home at risk and possibly people... Here you're hooking random chargers up to lithium batteries?!

I understand lithium chargers and have even designed a few and if it were me I'd buy the correct charger for $50 and keep a closer eye on it this time around.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[shakezilla]

Thank you for your response.

The only part of the charger I'm missing is the harness/stand - still have the original plug. The harness is the only part I'm trying to re-create.

With the solar panel, I'm just looking to get it wired to the Icom in an emergency situation. I'm commonly in the wilderness, and if for some reason the battery dies, I would just like to get enough charge to send out a quick SOS. By no means would I be overcharging, risking fire.

 

[mikekilroy]

I'm totally with Itsmoked - get the right lithium charger....

As you probably know from your past ham radios, nicads & nimh like constant current, lead acid like constant voltage. Lithium is more complex and needs constant current charge and then voltage charge. You really are playing with literal fire by not having a proper charger on that.

We have hamfests/hamventions in our area year round almost every weekend within a few hours drive. I suspect you do to. If you don't want to go spend the $50 at a ham radio store, or $ 30 on ebay, for the missing parts, why not go to the next hamfest and pick it up for $ 5? At least then you don't have to worry about burning down the house?

73,
AC8V

http://www.KilroyWasHere<dot>com