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Will I be able to charge a Lipo

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LIGHT

Thu Mar 10 2011, 07:06PM

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It's a pouch looking type, there are two.

klugesmith

Thu Mar 10 2011, 09:05PM

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Battery University is an authority I respect for info on LiPo and other batteries.

"Charge and discharge characteristics of Li-polymer are identical to other Li-ion systems and do not require a special charger. Safety issues are also similar in that protection circuits are needed. Gas buildup during charge can cause some Li-polymer in a foil package to swell, and equipment manufacturers must make allowances for expansion. Li-polymer in a foil package may be less durable than Li-ion in the cylindrical package. Li-polymer is not limited to a foil package and can also be made into a cylindrical design."

That source echoes what others have just posted in this thread:
Charging Li-ion batteries:

Charging batteries with a power supply:

I have done the latter twice in the last 2 weeks, recovering some Nikon batteries that had sat in cameras unused for many months, and had terminal voltage so low that Nikon charger wouldn't start to charge them. (Maybe that was due to internal, active, reversible protection circuit ? ) On the bench, their I/V/time behavior was right out of the textbooks cited above.

Steve Conner

Thu Mar 10 2011, 09:15PM

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This is all very true, but we need to know if the battery has a charge circuit built in.

You said you plugged a PSP charger in and the charging light lit up. The charging light on what? The DVD player, the PSP wall wart, the battery pack itself?

You said that something took 9-12 volts in to charge. What is that thing? The DVD player? The battery? If it's the battery, it must have a charger built in, because a 2-cell battery takes 8.4V to charge.

I've designed Li-Ion power systems as part of my day job, and they do indeed charge just like lead-acids, except you're not supposed to leave them on "trickle". I've often charged them with a bench power supply as described in the article.

The pouch type cells are usually the same chemicals as the 18650 type, just squished into a plastic bag instead of rolled up in a metal canister. So, they behave the same electrically. I've used them interchangeably.

LIGHT

Thu Mar 10 2011, 09:30PM

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It shows two pouch looking cells, and then it has a small curcuit that has a couple of IC's and one small transistor, this is on the battery pack. The LED is on this circuit.

The LED is on the battery's circuit.

LIGHT

Thu Mar 10 2011, 09:56PM

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Here are a few picks to help.

Steve Conner

Thu Mar 10 2011, 09:57PM

Registered Member #30 Joined: Fri Feb 03 2006, 10:52AM
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Well then, I'd say the battery has a charger built in and you can just plug any power supply of 9 to 12V in there.

But if the power supply is less than 8.4V (or 9V or whatever) the battery probably won't charge fully. I don't think that will damage it, but it would be better to get one of the recommended voltage.

LIGHT

Thu Mar 10 2011, 09:59PM

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So because it has a built in circuit, I can use my 12v 32AMP PSU, ripped from a PS3?

Steve Conner

Thu Mar 10 2011, 10:00PM

Registered Member #30 Joined: Fri Feb 03 2006, 10:52AM
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If it is 12V and you don't connect it up backwards, I don't see a problem.

I'm pretty sure the little board inside the battery is the charger, and what you thought was the charger is just a wall wart.

LIGHT

Thu Mar 10 2011, 10:05PM

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Ahh so it was just a small wallwart to supply unregulated power to the circuit in the battery pack, so it then charges it with better precision, etc.

Thanks, will it shut off when its charged? because if I leave it overnight and it does not have that safety feature it will overcharge and blow up?

LIGHT

Thu Mar 10 2011, 10:42PM

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Steve McConner wrote ...

If it is 12V and you don't connect it up backwards, I don't see a problem.

I'm pretty sure the little board inside the battery is the charger, and what you thought was the charger is just a wall wart.

I just soldered a 12v 1.5A wallwart to the PSP adapter (because it fitted), and it shows a red LED indicating it's not charged et, so it is working? (also when I plugged in 5v from the PSP, it showed as if it was fully charged)

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