Li-ion Charger Help

[rockz4532]

I have ordered a AW RCR123a battery, and a AW 17670 batt from Lighthound. They should be here Thursday.

Is there a problem with using wires and magnets to charge the 17670 with a nano charger? (besides charging the battery backwards)

Also what is the expected charge time for both batteries? I've heard 3 hours for the RCR, but I just want to verify.

Is there any safety or charging issues with the Nano? Since it costed less than $10, I'm a bit worried with the quality and charging. Does it actually measure the voltage of the cells?

Any answers appreciated!

 

[mdocod]

should be ok.

With li-ion cells and charger, it's ALWAYS best to check yourself with a volt-meter whether your charger is doing it correctly. Since cheap chargers vary from batch to batch, nobody can answer your question with 100% accuracy but you.

-Eric

 

[rockz4532]

Ok, thanks. IIRC, once the batteries get to around 4.1v, it is fully charged?
How do I know when a battery is dead? 3.6v?

 

[mdocod]

4.10-4.20V is "full"
Anything over that is over-charged.

And yes, 3.6V is, for intents and purposes, empty. (there's about another 10% capacity in there if you suck it all the way down to 2.5V, but that's really unhealthy for the cell).

If you can figure out a way to keep your cells between 3.7V and 4.1V most of the time, then they will last a really long time.

 

[Ajay]

Is there any safety or charging issues with the Nano? Since it costed less than $10, I'm a bit worried with the quality and charging. Does it actually measure the voltage of the cells?

Any answers appreciated!

:thumbsdow One of the most hazardous times for a Li cell is during charge (and for you). I think you should buy a proper charger, you get what you pay for. CPF folks here use the Pila charger http://www.pilatorch.com/BatterySys_charger.htm

I use a hobby charger and external power supply. Check towerhobbies.com and other hobby shops.

Say NO to cheap chargers! :nana:

 

[rockz4532]

i only have 2 batteries, the nano will do fine for me. But it charges hell slow. the batt was at 4.11v at 4:00, and at 6:00 it was at 4.13. Man, this is boring, supervising the charger, then finally at 6:45 it was done at 4.14v. Way too slow. :shakehead Ill just play some ps3 while the 17670 is charging.

 

[Black Rose]

I think you should buy a proper charger, you get what you pay for. CPF folks here use the Pila charger http://www.pilatorch.com/BatterySys_charger.htm

The Pila is great for folks in the US since it can be obtained at an affordable price.

Unfirtunately for those CPFers outside the US, it is a royal PITA to get one affordably.

A $49 charger quickly turns into an $85 to $100+ charger once you factor in international shipping charges and exchange rates.

 

[moldyoldy]

should be ok.

With li-ion cells and charger, it's ALWAYS best to check yourself with a volt-meter whether your charger is doing it correctly. Since cheap chargers vary from batch to batch, nobody can answer your question with 100% accuracy but you.

-Eric

I certainly concur with this advice! For example, the Nano charger has quality problems. Of the dozen or so Nano chargers that I have had cross my desk, the open circuit voltage ranges from 4.12 to 4.30 volts. Suffice to say, the 4.12 max voltage unit will not charge an RCR123a cell to full charge. Most of the Nano chargers have an open circuit voltage in the range of 4.25 to 4.28 volts. If the open circuit voltage is too low, the charger will take a loooong time to charge a cell to cutoff, including longer than overnight to "charge". I have also had several outright failures. Some were DOA, some failed after a few hours. If you are willing to order 2 Nano chargers and hope for one "good" charger, it may be worth it since the charger is so small and is 120/240VAC capable - nice for traveling.

The main "Pita" with the Pila charger is the sensitivity to jiggling or bumping to which the charger immediately cuts off charging and sets the LED to green/charged. Get used to pressing the "reset" button if you bump the charger!

Frankly, the consumer market for Li-Ion chargers is immature by comparison with Ni-MH chargers. I am excluding the hobby chargers that require external holders and clips. There are plenty of reasonable Ni-MH chargers available to consumers.

 

[rockz4532]

Is there any charger besides the pila that cpf-ers think of good quality?

My open circuit voltage on my nano is 4.25v, so I'm good. For me, i am only going to charge to 4.10 for my cells, otherwise its painfully slow. I read a thread which says the current tapers down from .45a as the cell gets more charges, explaning the time for charging. Is 4.10v ~90% of the cells capacity?

for the 17670, I charge them using some old multimeter wire (12ga?) and donut magnets. It works quite well.

 

[SilverFox]

Hello Rockz,

The Schulze line of chargers are of very good quality... :devil:

Tom

 

[Luxbright]

I second Tom on the Schulze chargers, batteries come out cool after a full charge. Love it.

 

[mr.snakeman]

Hello Rockz,

The Schulze line of chargers are of very good quality... :devil:

Tom

Link, please.

 

[SilverFox]

Hello Mr. Snakeman,

Here you go.

Tom