General questions - RCR123

[skins2]

Hello

Firstly I'd like to say what an informative and helpful forum this seems. Thanks to searching through posts (and 'alfablue' on bikeradar.com) I've chosen and bought the following for my bike:

2x Fenix P3D Q5
2x Fenix P2D Q5
4x AW protected RCR123 cells for the P3D's

What I now need to buy are some 3V RCR123 cells for the P2D's.

I also have a few questions I couldn't find the answers to by searching:


1. Can anyone verify if this is a genuine Ultrafire charger?
http://www.oknewshop.com/products/ultrafire-30v36v-cr123a-charger-1236.html
I only ask because they seem so cheap.

2. Will the Tenergy RCR123's (2nd product on page below) charge safely on the above charger set to the 3V charge?
http://thephotonshop.co.uk/page43.htm
And if so I assume they only display the warning to encourage you to buy their charger/battery pack for more money.

3. If the 3V Tenergy RCR123's were charged in the 3.7V mode could they explode? I'm wondering if it's worth buying the Tenergy charger/battery pack, even though I only need 2 batteries, in case I forget to switch back to the 3V mode.


Thanks in advance for your help, Matt

 

[jirik_cz]

1. Can anyone verify if this is a genuine Ultrafire charger?
http://www.oknewshop.com/products/ultrafire-30v36v-cr123a-charger-1236.htmlI only ask because they seem so cheap.

Probably eyes. They can be purchased for even lower price on some other online shops.

2. Will the Tenergy RCR123's (2nd product on page below) charge safely on the above charger set to the 3V charge?
http://thephotonshop.co.uk/page43.htm
And if so I assume they only display the warning to encourage you to buy their charger/battery pack for more money.

No. These RCR123 are common 3.7V cells with regulation circuitry that lowers the voltage to 3 volts. These cells need special chargers that charges to 4.4V. btw. don't believe the 900mAh capacity, they will be 500mAh at best.

 

[skins2]

Thanks for the answers. I'll go for the Tenergy charger/battery pack then.

 

[skins2]

Just two more questions. What's the 3v mode on the charger for? Can it be used to charge the 3.7v AW batteries to just 3v so they can be used in the P2D?

I know it's a long shot, but if you don't ask...

 

[jirik_cz]

3V mode is for charging LiFePo4 cells. You can get them here. If you would use this setting for 3.7V cells they would be charged only to 0-20%. So you would get none or very short runtime with them.

 

[mdocod]

Instead of the P2Ds, get this:
https://www.4sevens.com/product_info.php?cPath=93&products_id=501 so that you don't have to order a special set of lousy cells just for the P2Ds. The EX10 will run fine on a regular 3.7V cell.

Instead of the P3Ds, get this:
http://www.bugoutgearusa.com/jetiiiprost.html
It's similar in size and shape, and will have double the runtime when used with a single 18650 as compared to a P3D running on 2xRCR123s.

Get a Pila IBC charger and some spacers to charge the RCR123s with.

Eric

 

[naked2]

Hello...

I've chosen and bought the following for my bike:

2x Fenix P3D Q5
2x Fenix P2D Q5
4x AW protected RCR123 cells for the P3D's

He already bought the Fenixs!

 

[Marduke]

The charger you linked is cheaper here
http://www.dealextreme.com/details.dx/sku.1236

 

[mdocod]

never-mind, I misread,

----------------------

The Tenergy 3.0V RCR123s are actually 3.7V cells with voltage regulators on them, they actually require a charge voltage of ~4.4V. So you could charge them in a regular 3.7V charger, and they would charge up to ~80%.

I personally really don't like any of the rechargeable options for the P2D and P1D lights.

1. You can use a 3.7V cell, often overdriving the electronics and LED, and loose all low modes. [edit in :some users report permanent damage.]

2. You can use a 3.0V voltage regulated cell (like the tenergy), have to deal with lousy capacity (~500mAH @ ~3V), energy storage converted to heat in the cell by a voltage regulator, and have to own a charger that would cause an explosion if any other li-ion cells were accidentally loaded into it. [edit in: 4.4V charge termination]

3. You can use a 3.0V LiFeP04 cell, suffer from dramatically low capacity, (~350mAH). This option also has nothing in place to prevent over-discharge, so you have to make sure you keep track of your usage to prevent it yourself.

----------------------

Using rechargeable cells in a P1D or P2D is a crap shoot.

 

[jeremyison05]

I'd suggest buying some cells from AW either direct from him or here http://www.lighthound.com/AW-RCR123a-Protected-750-mAh-Battery_p_0-114.html . They're quality cells and possibly the safest ones out there. And you can also pick up http://www.lighthound.com/Ultrafire-36-volt-or-3-volt-RCR123-Lithium-Battery-Charger_p_6-2270.html from lighthound. Your P3D and P2D can both run on the RCR 123's without fear of hurting them, I think four7's has said the buck circuit works up to something like 12v in them? The 3.7v setting is what you'll want to use to charge these cells.

I own a P3D and use these cells in it, never had one problem, and I don't lose any of my low modes while using them fresh off the charger, you'll be happy with them. :twothumbs

 

[naked2]

The P2D doesn't fully support 3.7V Li Ion cells, it will only work on turbo and strobe, you lose hi/med/lo. After prolonged use at this voltage, you will lose them PERMANENTLY!

However, the P3D works on all modes/levels at 8.4V.

 

[jeremyison05]

Really? I thought four7's said the P1/2D would work fine. Either way, from what I gather these are going to be used as bike lights. So the low probably isn't an issue.

Edit: found the post

those graphs in the first post are 2xcr123a and 2xrcr123.
Fenix specs state that it's fine with 2xrcr123. It's a buck circuit.
I've tested it up to 16v (unofficial )

 

[naked2]

Yeah, but that's the P3D (2 cells). But believe me, if you want to burn-out the hi/med/lo levels on your P2D (I don't know about the P1D, never owned one), keep using it at 3.7~4.2V; I know first hand, it happened to mine.

It was the P2D CE (P4), and Lighthound refunded me in full after almost a year. When I returned it the Q5 version was out, but when I asked John (at Lighthound) if the Q5 version fully supported 3.7V Li Ion and he said "no", I said "I'll pass", and took the refund. I may be wrong, but I believe the brand new PD20 is STILL the same (too bad).

Because of this experience, I'll never again buy another light unless I know for sure that it will FULLY support Li Ions, regardless of how many or what size cells it takes!

 

[jeremyison05]

Ya, that was him talking about the P3D. I've never personally owned a P2D so i'll take your word for it