Li-ion battery charging

[bromleybysea]

My Cannon camera uses a 3.7 v battery which is supplied with a mains charger which has an output of 4.2v. I want to buy a charger for use on the boat and all the (cheap) ones I have seen that are sold for this battery are 12v out. Can I safely use a 12v charger on a 3.7v Li-ion battery?

 

[philip_stevens]

Get one of these small inverters from Lidl and it will do the same job with your present charger.

I know it is taking 12v to 240v and down again to 4.2v, but it will not effect your camera battery.

I use a slightly bigger inverter to run our LCD screen TV via the power pack, on the boat rather than power it directly from the 12v as it gives a more stable voltage.

I also use the inverter to charge my camera battery, shaver battery, LED inspection lamp battery, mobile phone battery, and handheld VHF battery.

 

[VicS]

You dont say what battery it is but Jessops list two. One for the LP-E5 battery and one for the LP-E6. but they dont say what the output volts are.

At the prices from Jessops for those two (£99 and £169!) a small inverter as Philip suggests would look like a sensible option.

 

[noelex]

As others have said use an inverter.If you have a lot of LI-ion batteries a hobby charger is a more efficient option, but you need to know what you are doing. Be careful with Li-Ion batteries they can explode and burn with a fire that is very difficult to put out if charged incorrectly. Do not connect to any 12v charger under any circumstances.

 

[AngusMcDoon]

What happens if you stick too many volts into a lithium battery...

Clickee...

That was a LiPo rather than a LiIon, but the volatile bit is the lithium.

 

[bromleybysea]

Very convincing- I will go down the inverter route!

 

[maxi77]

It may be worth seeing it there is a USB charging lead for your camera, manny things around this voltade do =have then these days, you can then get a gigar lighter type 12V to USB adapter

 

[Evadne]

Lithium ion (and Lithium Polymer) batteries will take prodigious amounts of current with no harm if you let them, but are fussy about the charger Voltage and should never ever ever be charged at higher Voltages. I think one of the "LiPo fire" videos available on the web was done by charging a cell at 5 Volts. It is probable your cell will have built in safeties to prevent it exploding, but - well, you get the picture.

If your charger outputs 4.2V, then you could probably go up as far as 4.5V without harm. Anything below 4.1V will not get you full charge and below 3.9V is too low, really. From the user's point of view, the difference between "Lithium Ion" and "Lithium polymer" is pretty academic.

 

[pteron]

Even 4.5V is too high for Li Ion. The specs on the charging voltage are generally +/- 25mV. Having said that, the 'charger' is probably only a voltage source, the intelligence will be in the camera.

Does the charger plug into the camera or does the battery sit in the charger?

 

[Anwen]

More to the point, the charge current, voltage and cutoff detect are all critical to Lipo and Li Ion cells. Don't use a charger which doesn't have a specific lithium program - certainly don't use a general purpose charger unless you can select the number of cells and Ah rating. As others have said the inverter plus charger which came with the camera is by far and away the safest option.

 

[dmh]

most camera shops have chargers for the Lion batteries for cameras, many are multi input voltage including 12v, really designed I suspect for cars and not boats, but they work ok

 

[James_Hortop]

Careful using a modified sinewave inverter - some Lithium Ion chargers won't run from them or, if their filtering isn't adequate will induce pulsing voltages to the battery. Use a sinewave inverter if you want to be totally safe.

james