New 9V Li-Poly batteries/charger too!

I was looking around and found this new 9V charger that charges a new 9V Li-Poly battery! The only thing is that I had some Ipower 9V Ni-MH and didn't have good luck with them! Look here: Charger

Hmm. Less capacity than an alkaline tho.

-john

Hello Bill,

Help me out here... my brain is a little fuzzy tonight.

Li-Poly cells run at 3.7 volts per cell and charge up to 4.2 volts per cell. How are then getting 9.6 volts for their 9 volt cell?

Tom

SilverFox said:

Hello Bill,

Help me out here... my brain is a little fuzzy tonight.

Li-Poly cells run at 3.7 volts per cell and charge up to 4.2 volts per cell. How are then getting 9.6 volts for their 9 volt cell?

Tom

Click to expand...

Tom:

It's that new math! :nana:

EDIT: Yep, I was wondering myself unless they have a circuit like the 3V Li-Ion cells?

Tom:

I emailed Ipower asking about the above question. We'll see if I get an answer!

EDIT: Wow! Just got a email verification before my email get passed on to them!

John N said:

Hmm. Less capacity than an alkaline tho.

-john

Click to expand...

Considering that most 9.6v (9v) Ni-mh batteries had 150-200mah capacity this 400mah li-poly is a vast improvement.

John

Still no answer from Ipower on how they get 9.6V when a Li-Poly cell is 4.2V fully charged!

Of course, lots of businesses are off this week including me! :rock:

I put the question to Thomas Distributing who seels the batteries also and got a response stating that these Ipower 9V batteries are really a 2S Li-Poly battery with a max of 8.4V. Now would that be a problem in some applications? It might be!

wptski said:

I put the question to Thomas Distributing who seels the batteries also and got a response stating that these Ipower 9V batteries are really a 2S Li-Poly battery with a max of 8.4V. Now would that be a problem in some applications? It might be!

Click to expand...

Highly unlikely.

Check the graphs on the data sheets. A 9 Volt alkaline is something like 10% discharged at 8.4 Volts.......

Doug Owen

Hello Doug,

It may start out at 8.4 volts, but mid point voltage should be around 7.4 volts. Does that seem a little low?

Tom

SilverFox said:

It may start out at 8.4 volts, but mid point voltage should be around 7.4 volts. Does that seem a little low?

Tom

Click to expand...

Tom, remember all those years when all we had in a rechargeable "9V" was a NiCad that only really put out 7.2V? It seemed to work in every 9V application I had. :shrug:

Doug Owen said:

Highly unlikely.

Check the graphs on the data sheets. A 9 Volt alkaline is something like 10% discharged at 8.4 Volts.......

Doug Owen

Click to expand...

It's irrelavant! What's a 9V alkaline start out, fresh? This battery starts out at 8.4V. It "all" depends on the application and what it considers a low battery and the capacity is below a alkaline too.

Hello Doug,

That's right. The NiCd and NiMh 9 volt batteries have 6 cell in them. 6 cells at 1.2 volts works out to 7.2 volts, so 7.4 volts would be an improvement.

Tom

vcal said:

Tom, remember all those years when all we had in a rechargeable "9V" was a NiCad that only really put out 7.2V? It seemed to work in every 9V application I had. :shrug:

Click to expand...

vcal:

I've never had a problem either but I'd say that it's "possible" but not "highly unlikely".

I received an email from Ipower a few minutes ago stating that the 9V Li-Poly batteries "aren't" 9.6V and have instructed Thomas Distributing to change their on-line description. I think that they have made the changes already.

SilverFox said:

Hello Doug,

It may start out at 8.4 volts, but mid point voltage should be around 7.4 volts. Does that seem a little low?

Tom

Click to expand...

Perhaps to you and I, but to the device that expects to see an alkaline battery there (say like my garage door remote) it'd better still work. Eveready says it's still got 'plenty of juice' (at 7.4 Volts) and it works just fine in my radio........

Doug Owen

wptski said:

It's irrelavant! What's a 9V alkaline start out, fresh? This battery starts out at 8.4V. It "all" depends on the application and what it considers a low battery and the capacity is below a alkaline too.

Click to expand...

Sorry to disagree, it is absolutely relevant. To the device being powered, everything is fine.

Again, if you call a 10% discharged alkaline dead (because it's now 8.4 Volts) you'd better not advertise you can use 9 Volt Alkaline batteries......

And yes, alkaline has larger capacity (although some of that is at a lower voltage and may not be useful.....). However this is a great step up for the already useful NiMH batteries in this size. If it doesn't suit you, don't buy it.

Doug Owen

SilverFox said:

Hello Doug,

That's right. The NiCd and NiMh 9 volt batteries have 6 cell in them. 6 cells at 1.2 volts works out to 7.2 volts, so 7.4 volts would be an improvement.

Tom

Click to expand...

And the capacity is like double, right? FWIW, I have a couple of 8.4 Volt NiMH (one more cell, lower capacity per cell). The only place I can see a real difference is with the PakLite where there are two LEDs in series with a resistor. By the time you subtract two Vfs at say 3.6 Volts each there's not much left of 7.4 Volts..... The 8.4s are brighter and run longer too.

Doug Owen

Doug Owen said: Sorry to disagree, it is absolutely relevant. To the device being powered, everything is fine.

Again, if you call a 10% discharged alkaline dead (because it's now 8.4 Volts) you'd better not advertise you can use 9 Volt Alkaline batteries......

And yes, alkaline has larger capacity (although some of that is at a lower voltage and may not be useful.....). However this is a great step up for the already useful NiMH batteries in this size. If it doesn't suit you, don't buy it.

Doug Owen


I don't understand, unless you own every 9V device ever made, how you could say that there "won't" be a problem. I've never had a problem using 9V Ni-MH batteries but who knows for sure, you?

I know that we're talking 9V batteries here but there was one report of a camera not powering up using Battery Station's AA lithium cells. Another user had to start up with the screen OFF to avoid the initial voltage drop at start up. I on the other hand I got such great runtime in my Fluke 189 with these cells that Fluke asked BS for samples to test!

Another point is that I had ten IPower Ni-MH 9V batteries that were pure junk. I didn't get very many cycles if you want to call them cycles. I sent a couple to Silverfox for testing and he had the same problem. He disected one and found a dead cell.

Ipower is coming out with a new model Ni-MH 9V battery shortly.

Bill,

I have an iPower Ni-mh 9v that is 9.6v & 250mah. I use it in my Torfino Ice Light when directing traffic at night. Is the new iPower you just spoke of a 9.6v or 8.4v? Is the capacity higher than 250mah?

Thanks,

John