New Li-ion Battery Charger - 3 contacts on battery?

[Speakercon]

I'm looking into building a charging circuit for the following battery:

The reason is I don't trust the charger it comes with not to burst into flames (its a cheap import with US plug on & single insulation cable).

Still at the idea phase, found this PCB http://www.ebay.co.uk/itm/350817365885?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649 and was wondering if it would be suitable? Also the battery has 3 contacts which I'm not sure about..
Any help appreciated

Edit: This is the original charger.

 

[greasedmonkey]

While I don't know your background or knowledge base, I mean you no offence when I say the following.

Please don't feck about with Li-ion batteries unless you really know what you are doing. Those things can go with a hell of a bang if you get the charging circuit wrong.

I have been an electronic design engineer for 20 years and I would not attempt my own charging circuit unless I had all of the specifications of the battery pack. I've seen em go up.

 

[jbainbridge]

I expect the third contact is to do with temperature sensing / overcharging protection. Why not use the charger? You seem to over complicating things.

 

[viewer]

Dreamliner

 

[Speakercon]

No offense taken! My knowledge is more electrical wiring than circuit components. Thanks for the advice, I am aware of the potential consequences hence asking for opinions, it seems this is more complex than I imagined so I'll stick with the existing charger, and just keep an eye on it!

 

[conny]

Change the plug for a suitable British one and fuse accordingly.

 

[Speakercon]

Change the plug for a suitable British one and fuse accordingly.

I was gonna do that. My only concern was the quality/saftey of the circuit inside.

 

[ban-all-sheds]

Change the plug for a suitable British one and fuse accordingly.

Assuming it will be OK on 230V.

Speakercon - how come the charger came with that plug? Where did you buy this stuff?

 

[westie101]

Dreamliner

Not just that, two freight aircraft fatal crashes have been ascribed to these batteries

 

[Speakercon]

Change the plug for a suitable British one and fuse accordingly.

Assuming it will be OK on 230V.

Speakercon - how come the charger came with that plug? Where did you buy this stuff?

I haven't bought anything yet. The item is a set of walkie talkies from ebay, and yes they are cheap imports BUT the reviews for the actual radio's are very good, it was just the chargers that concerned me saftey wise. It does say '100V~240V/50Hz'. My idea was to remove the psu/transformer inside and use with an external plugin psu, however I feared this may be quite complex as the psu/charger circuit may be built as one but I don't know for sure.

 

[Lectrician]

If it says 100-240, why are you contemplating taking the circuit apart? It's just the single insulated cable which would perhaps be a good idea to replace.

Are you sure tese imports are licenced for use here?

 

[ban-all-sheds]

It's just the single insulated cable which would perhaps be a good idea to replace.

Why?

Surely, to be imported and sold here, it must comply with all the appropriate standards, and be CE marked?

 

[bernardgreen]

Not just that, two freight aircraft fatal crashes have been ascribed to these batteries

And a fire at a remote communications facility carried emergency service comms.

It is a high risk technology.

 

[jonez]

It's just the single insulated cable which would perhaps be a good idea to replace.

Why?

Surely, to be imported and sold here, it must comply with all the appropriate standards, and be CE marked?

That's a good point but a lot of 'imported' kit is bought direct from China or the US so technically it's the responsibility of the purchaser to CE mark it.

Most of these grey imports have a CE mark somewhere but usually it's just for show - there's no way they'd pass EU regulations.

 

[phatboy]

CE as in Chinese Export ?!!