PowerGenix NiZn batteries

[Barrie]

can a standard AAA-AA charger be used for these 1.6v cell or would i need to buy yet another charger :thinking:

 

[tebore]

You'll need their kind of charger.

 

[bcwang]

Thanks to your post I ended up ordering a kit! I never heard of this before I read this post, but doing some research it looks like something that could be interesting with the higher voltage and lower internal resistance.

I'm thinking in something like the Nikon SB800 flash, you could get much faster recycling times with 4 of these cells and even beat 5 Nimh cells. (4x1.6 > 5x1.2)

I'm also hoping it can power 1AA flashlights like the L1D and Quark AA with a higher turbo mode close to the 2AA versions in brightness.

I guess I need more info on or will soon try and figure out:
-what devices are known to be safe with this (worried about over-voltage) I think these are 1.6v nominal but 1.9v hot off the charger. How high are AA lithiums?
-what is the self discharge rate
-what is the correct safe discharge cut-off voltage
-what kind of voltage drop under load
-what is the max amps I can safely draw

There doesn't seem to be much information about these cells so far which is surprising considering how much people on this forum are into batteries.

 

[xenonk]

You definitely need a charger designed for NiZn. The charging properties are too different from NiMH or NiCd.

The main reason I haven't pursued NiZn myself is because I'm already all set up with and satisfied with my LSD NiMHs. I'm interested in and have been keeping an eye on the chemistry, though.

AA Lithiums start at 1.7V. NiZn isn't a very widespread chemistry yet, so those 1.9 volts could very well some devices until the electronics industry accounts for them.

I haven't yet found satisfactory information regarding self-discharge. Nor the discharge characteristics, though it should be pretty impressive. The chemistry looks to be hardy.

You're actually supposed to charge these batteries fast, no slower than 0.5C and ideally at 1C. They don't like long charges at all. The suggested charge cycle is a 1.9V CC/CV algorithm, with a hard time limit.

 

[bcwang]

Ran one on a CBA-II, didn't meet capacity figures. Maybe it'll improve with cycles or under less load. The good thing is it seems to stay cool during charge and during discharge. They also feel lighter than nimh batteries. I'm still trying to figure out the charger. I'm too chicken to use this anywhere so far other than my Quark. I've heard of burned out flashes and broken cameras using this type of battery, so I'm checking out voltage range specs for each device before I try it.

Cell Rating 1500mah typical, 1350mah minimum

My Test
Discharge Rate: 1.5 amps
End of discharge: 1197 mah

 

[Chrontius]

Malkoffs will regulate on anything, so when are we going to see something sized for using in a 6r?

 

[tebore]

I've heard of people blowing their flashed on these batteries.

Thanks to your post I ended up ordering a kit! I never heard of this before I read this post, but doing some research it looks like something that could be interesting with the higher voltage and lower internal resistance.

I'm thinking in something like the Nikon SB800 flash, you could get much faster recycling times with 4 of these cells and even beat 5 Nimh cells. (4x1.6 > 5x1.2)

I'm also hoping it can power 1AA flashlights like the L1D and Quark AA with a higher turbo mode close to the 2AA versions in brightness.

I guess I need more info on or will soon try and figure out:
-what devices are known to be safe with this (worried about over-voltage) I think these are 1.6v nominal but 1.9v hot off the charger. How high are AA lithiums?
-what is the self discharge rate
-what is the correct safe discharge cut-off voltage
-what kind of voltage drop under load
-what is the max amps I can safely draw

There doesn't seem to be much information about these cells so far which is surprising considering how much people on this forum are into batteries.

 

[xenonk]

My Test
Discharge Rate: 1.5 amps
End of discharge: 1197 mah

The voltage sag seems a little steep. Did they come off the charger at 1.9V open circuit?

It could be that these need a forming charge or a few cycles to break in, so the numbers may change after some use.

IIRC, the capacity rating for NiZn is done at 1C discharge so your test should be label accurate.

 

[bcwang]

tebore,
Yes, I've heard of people blowing their flashes with these batteries too. The Nikon sb-600 seems to be the one I keep reading about that won't work. Though I also read the sb-800 and sb-900 work great with these batteries. I'm still too chicken to try them in anything without asking about operating voltage first. I don't want to blow my canon flashes or any of my other electronics.

xenonk,
I don't remember what voltage it comes off the charger exactly, but 3 days of resting, the battery is 1.79v. Pulling half an amp, it showed 1.75v.

If their testing is done at 1c, I should be getting higher mah figures. I guess I'll try it again after a few cycles. Maybe it just needs a few cycles to get going just like nimh.

It seems the discharge curve is not as flat as nimh. Dropping more gradually overall, but not holding a flat voltage for any large range. I guess voltage sensitive devices will have more varying performance throughout the discharge of the batteries.

 

[bcwang]

ok, I did a bit of discharge testing to determine internal resistance. I discharged until it looked like the voltage stabilized. The cell was charged 1 week ago.

0.2 amp = 1.7v
1 amp = 1.65v
5 amp = 1.52v
10 amp = 1.37v

20 amp was bad, it initially looked like it held around 1.13v, but then it kept dropping to 1v so I stopped the test. The cell felt quite hot. So I stopped testing completely and left it as I started analyzing the numbers. 5 minutes later when I went to take it out of the CBA II it was burning hot! Hopefully it's not an internal short but that it simply got hot from the 20amp test and it is just taking time for the heat to transfer out. After it cools down I'm going to test it to see if it's still working fine.

Anyhow, from the looks of the numbers it seems the internal resistance is around 30 milliohm. This is better than the 40-60 milliohm I've measured from my better nimh cells.

 

[VidPro]

ohh Thank you Bcwang for doing the test, glad i saw this
Discharge Rate: 1.5 amps
End of discharge: 1197 mah <--- that SUCKS (closest thing to a raspberry icon)
if there wasnt an almost .5v higher voltage potential under load i would say that really sucks , but it just sucks

 

[bcwang]

ohh Thank you Bcwang for doing the test, glad i saw this
Discharge Rate: 1.5 amps
End of discharge: 1197 mah <--- that SUCKS (closest thing to a raspberry icon)
if there wasnt an almost .5v higher voltage potential under load i would say that really sucks , but it just sucks

Don't forget, that was only after the very first charge. I have no idea if it will get better as I haven't had a chance to put any cycles on them yet.

Update to my load and testing. I did kill the cell. It only gives 200 mah after a full charge and discharged at 1.35 amp. Even lowering the current to 200ma at that point it gives an additional 60 mah.

I'm waiting to hear from powergenix on what the max continuous current of the cell is. Obviously 20 amp is unacceptable.

 

[VidPro]

great, you fried it, more wonderfull data.
mabey you should put that right under the graph or make a "schwoop" graph for 20amps

 

[MarioJP]

what would happen if you put these batteries in a nimh charger??

 

[VidPro]

what would happen if you put these batteries in a nimh charger??

the results would be unpredictable, because you didnt say WHICH charger. many of them just wouldnt charge it fully, some would GASS the cell out, ruining it, some might show a high signal and not charge , Not because it was high resistance but because the tests punches in some amps and tests the voltage.
at any rate the cell wants a CC/CV type of charge, not the usual Ni-Mh type of charging. CC/CV can potentially be easily done with a power supply, or simple voltage control, and the precise parameters. (if ya trying to be cheap)

 

[MarioJP]

the results would be unpredictable, because you didnt say WHICH charger. many of them just wouldnt charge it fully, some would GASS the cell out, ruining it, some might show a high signal and not charge , Not because it was high resistance but because the tests punches in some amps and tests the voltage.
at any rate the cell wants a CC/CV type of charge, not the usual Ni-Mh type of charging. CC/CV can potentially be easily done with a power supply, or simple voltage control, and the precise parameters. (if ya trying to be cheap)

What if the NiZn is used in a charger like the La crosse BC-9009?. I know this charger will charge any battery that you put in it. I wanted to get familiar what this charger is capable of. It actually started to charge alkaline battery, but I immediately pull the plug.

Wow talk about a charger that charges lol.

 

[zipplet]

Erm, no. You can only change the NiZn batteries in the correct charger as what was said earlier. The LaCrosse will probably ruin them.

 

[MarioJP]

I was reading on the technical datasheet. It says that these batteries must be recharged after 30 days????. Is this true.

So much of eliminating the problem of self discharge eh?.

 

[MarioJP]

supposedly this is the next gen AA that can potentially replace NiMh, but the chart says "recharge after 30 days"????.

Wow this does not solve the self discharge problem in fact it worsens.

 

[bcwang]

supposedly this is the next gen AA that can potentially replace NiMh, but the chart says "recharge after 30 days"????.

Wow this does not solve the self discharge problem in fact it worsens.

I just did a test on a cell that was sitting for 2 months after a charge

Test parameters - discharge at 1350mah down to 1.3v
Capacity tested right after charge - 1175mah
Capacity tested 2 months after charge - 1121mah

That's pretty damn good charge retention right there. I should mention the voltage throughout the discharge curve was about 0.05v less than when tested freshly charged. Though it is still putting out far more voltage than a nimh in any state.

Powergenix replaced my damaged cell with a set of newer and supposedly improved ones. I'll be putting those to test soon.