Are Alkaline batteries usually better for low load applications?

20 posts / 0 new
Last post
Zebretta
Online
Last seen: 6 min 27 sec ago
Joined: 12/08/2016 - 18:57
Posts: 389
Location: USA
Are Alkaline batteries usually better for low load applications?

Tried some good rechargable AAA’s in some low drain devices and TBH, the Alkalines last a LOT longer.
About 2 weeks for the Alkys and about 4 days for the rechargeables.

Probably because the cut-off voltage for the devices is around 1.34v

Are there any rechargable AAA’s that are good for low drain applications?

Lexel
Lexel's picture
Offline
Last seen: 32 min 12 sec ago
Joined: 11/01/2016 - 08:00
Posts: 1252
Location: Germany

At 1.34V cutoff voltage the NiMh batteries are more than 85% full

For your device NiZn rechargable batteries with 1.6V may work, but the device needs to survive the voltage of a fresh fully charged cell

http://www.akkushop.de/de/ansmann-nickel-zink-lr03-aaa-nizn-akku-16-volt...

joechina
Offline
Last seen: 6 hours 12 min ago
Joined: 03/05/2016 - 08:23
Posts: 128

Normally yes, I have a digital clock 20 years old and changed the AAA twice.

You could try NiMH made for wireless phones they have normally a higher inner resistance.

I wonder if a batteriser (they are normally BS) could do the trick, because your device has this high cut off voltage.
https://en.m.wikipedia.org/wiki/Batteroo_Boost

Please correct me if I’m wrong.

wle
wle's picture
Offline
Last seen: 2 days 16 hours ago
Joined: 01/07/2015 - 13:49
Posts: 279
Location: atlanta ga

LSD NiMh is better but they age, and even when new, they still self discharge.
The LSD means “low self discharge”.
Also advertised as ‘pre-charged’.
Eneloops were the first, others followed.

Alkalines are best where either the load is very low [clocks], or the device is basically never used but you want it ready [flashlight by the furnace under the house].

Pete7874
Offline
Last seen: 7 hours 39 min ago
Joined: 11/23/2011 - 16:47
Posts: 213
Location: USA

joechina wrote:
You could try NiMH made for wireless phones they have normally a higher inner resistance.

Why would higher IR be a good thing?
Zebretta
Online
Last seen: 6 min 27 sec ago
Joined: 12/08/2016 - 18:57
Posts: 389
Location: USA

Lexel wrote:
At 1.34V cutoff voltage the NiMh batteries are more than 85% full

For your device NiZn rechargable batteries with 1.6V may work, but the device needs to survive the voltage of a fresh fully charged cell

http://www.akkushop.de/de/ansmann-nickel-zink-lr03-aaa-nizn-akku-16-volt...

I see where HKJ did a review of these batteries and his conclusion?
NiZn Review by HKJ

_“The cells might be useful for some special applications, but as replacement for alkaline or NiMH they are not very good. The higher voltage might damage equipment and the cells will be damaged when discharged to much.
I do not believe the cells are useable as replacement for alkaline or NiMH_.”
.
.
On the other hand……
If the device I want to use it in has an internal voltage cut off of 1.34v then I would never have to worry about over discharging right?

joechina
Offline
Last seen: 6 hours 12 min ago
Joined: 03/05/2016 - 08:23
Posts: 128

A high IR limits the self discharge.

So when you draw very little current, like in clocks, the current over a low IR can be significant to reduce runtime.

He said it’s low drain and with the high cut out = bad runtime.

Newer good designed devices should work with 0.8V to 1V, than you can use all the energy from a NiMH and alkaline.

flydiver
Offline
Last seen: 6 hours 11 min ago
Joined: 06/19/2013 - 19:16
Posts: 623
Location: Seattle, WA

joechina wrote:
A high IR limits the self discharge.

Are you sure? In my experience high IR indicates an old and failing battery that have much worse self discharge.
Good batteries like Eneloop always have a low IR, at least when new and good.
High IR will limit the current output, that’s for sure. They can only be low load.

Zebretta
Online
Last seen: 6 min 27 sec ago
Joined: 12/08/2016 - 18:57
Posts: 389
Location: USA

I ordered a few NiZN batteries to “try”, since the device I want to use them in does have the 1.34v cutoff so that means the NiZn’s won’t be damaged by over discharging (which I hear is their biggest killer). I was planning to only charge them to 1.7v thinking that that would “probably” not harm the device. Of course, that means they will not be fully charged.

I’m just looking for a balance. AAA Alkalines last about 18-25 days in the device (depending on the quality of the alkaline). If I can get the NiZn’s to power the device for 15 days I would be satisfied.

It’s also not “mission critical” by an means. I’m mainly having fun experimenting with the different chemistries. If I end up throwing out 4 useless NiZn batteries and just using Alkalines in the device that’s ok too.

Boaz
Boaz's picture
Offline
Last seen: 2 hours 56 min ago
Joined: 11/07/2010 - 09:31
Posts: 5957
Location: Birthplace of Aviation
you say you tried some “good “ nimh’s // What make what model ? and in what kind device ?

καὶ τὸ φῶς ἐν τῇ σκοτίᾳ φαίνει καὶ ἡ σκοτία αὐτὸ οὐ κατέλαβεν

AA Cycler
AA Cycler's picture
Offline
Last seen: 37 min 47 sec ago
Joined: 06/09/2016 - 23:22
Posts: 13
Location: Slovakia

Zebretta, I understand you tested NiZn cells, because your device has high cutoff for NiMH. According to your tests NiZn are not that robust and have lower cycle life than NiMH.

What about trying what joechina suggested? To get some AAA Batteroo sleeves and use them with AAA Eneloops. It’s not their intended use, but if one wants to use rechargeables in a high cutoff device they seem to be a good fit. (Given the battery compartment allows for extra space)

AAA Eneloops store 880 mWh @ 500 mA discharge. At nominal 1.2V they deliver 730 mAh. The sleeves would bump the voltage by 200mV. At 1.4V (+ some conversion losses) they should deliver 580 mAh. Not tested though, but if it was so the Eneloops with sleeves would give you comparable capacity than NiZn and would last 300 cycles…

Cycle count tests of AA batteries - http://aacycler.com

Zebretta
Online
Last seen: 6 min 27 sec ago
Joined: 12/08/2016 - 18:57
Posts: 389
Location: USA

Regardless of the brand they discharge tested at or over 900mAh. For NiMh AAA I was under the impression that was a good NiMh?

Zebretta
Online
Last seen: 6 min 27 sec ago
Joined: 12/08/2016 - 18:57
Posts: 389
Location: USA

AA Cycler wrote:
Zebretta, I understand you tested NiZn cells, because your device has high cutoff for NiMH. According to your tests NiZn are not that robust and have lower cycle life than NiMH.

What about trying what joechina suggested? To get some AAA Batteroo sleeves and use them with AAA Eneloops. It’s not their intended use, but if one wants to use rechargeables in a high cutoff device they seem to be a good fit. (Given the battery compartment allows for extra space)

AAA Eneloops store 880 mWh @ 500 mA discharge. At nominal 1.2V they deliver 730 mAh. The sleeves would bump the voltage by 200mV. At 1.4V (+ some conversion losses) they should deliver 580 mAh. Not tested though, but if it was so the Eneloops with sleeves would give you comparable capacity than NiZn and would last 300 cycles…

First, thanks for taking the time to post that. Good info indeed and I may try that.

My understanding is that batteroo sleeves are for disposable batteries only
But maybe they would work IF the device they were installed in had a built in voltage cut out (like my devices do).

These are basically Joule Theif circuits I believe.

At this point, the NiZn batteries seem to be doing a VERY good job as intended. My devices draw only .5milli-amps and I have achieved 500mAh capacity with my NiZn’s by adjusting the charge rate to 100milliamps or less and the discharge current to 100 milliamps or less.
At .5mAh discharge rate, I’m thinking the capacity could be over 600 easily.
.5mAh * 24hrs = 12mAh / day. 12mAh * 30 = 360mAh per month.
At this rate, they should power my intended devices for well over a month…nearly 2 months.
However, since the cut off is 1.34v, (and not the 1.2v lower limit I used in my tests), that might reduce the available capacity to about one month.
The question then would be …which battery can remain above 1.34v the longest?

Ironically the seller touts them as good for high-drain applications but from my testing, low drain is where they shine. Of course, I’m running a month long test now and will know more in 30 days. But my voltage tests thus far are promising. It “seems” they will make the 30 days and then some.

The question also becomes the number of cycles they will last I suppose. If I only have to charge them ± 10 times per year, it all becomes a moot point I suppose. It’s all getting a bit persnickety over a little difference maybe (except that it’s a hobby kinda sorta). Smile

Speed4goal
Offline
Last seen: 3 hours 35 min ago
Joined: 06/11/2016 - 13:03
Posts: 574
Location: Gulf Coast USA

Let us know how it goes. If all else fails you can get 150aaa alkalines chrome battery on amazon for $30 and call it done for the next 5 years.

Even on eBay I’ve found 180aaa ac delco brand for $30 I use rechargables in what I can but a few things its just better to use alkalines. And I just save the used ones until I go to recycle bin. Gives me a reason to dig around in it.

Sometimes on shoplet they will run sales on Duracell procells 6.24/24aa/AAA

Best buy a couple times a year does clearance on their advanced lithium’s for around $1/cell

Mr.Scott
Offline
Last seen: 1 day 4 hours ago
Joined: 02/13/2016 - 00:26
Posts: 208
wle wrote:
Alkalines are best where either the load is very low [clocks], or the device is basically never used but you want it ready [flashlight by the furnace under the house].

I tend to use Lithium primaries (not Li-Ion rechargeable) batteries in never used (emergency) devices. I am concerned about the alkaline leaking inside the flashlight, making it unusable when it is really needed, and ruining the device.

joechina
Offline
Last seen: 6 hours 12 min ago
Joined: 03/05/2016 - 08:23
Posts: 128

0,5mA draw and 1,34V cut off?
What BS device is this?
No way that normal NiMh last longer than Alkaline.

A good device is designed for a 0,8V or 0,9V cut off voltage.

Zebretta
Online
Last seen: 6 min 27 sec ago
Joined: 12/08/2016 - 18:57
Posts: 389
Location: USA

joechina wrote:
0,5mA draw and 1,34V cut off?
What BS device is this?
No way that normal NiMh last longer than Alkaline.

A good device is designed for a 0,8V or 0,9V cut off voltage.

Joe,
No BS.
These are remote controls (pagers if you prefer) for vehicle alarm systems.

I have carefully measured the current when in use and it’s .3mA but it fluctuates each time a pulse is transmitted to the receiver so I averaged it to .5mA.
When these devices reach approximately 1.3v-1.34v, they stop working, the displays go dead and the current is clamped (turned off).

I “assume” they are this way to ensure that as long as the battery is operating, the circuit ensures there is enough voltage/current to send and receive signals to the receiver, which could be up to 1/2 mile away…without damaging the circuit because in essence, they are transmitters and receivers.

They will run for about 4-5 weeks on a top quality alkaline AAA and I have purchased bricks of AAA’s for these but I wanted to reduce the number of batteries I have on hand so decided to try rechargables. NiMh was no good as they reach 1.34v quickly compared to the NiZn’s so far.

In high drain apps the NiMh’s are probably better where the cut off voltage is either non existent or lower.

joechina
Offline
Last seen: 6 hours 12 min ago
Joined: 03/05/2016 - 08:23
Posts: 128

Hm, so a radio transmitter.
You are sure you use the right type of battery? For me it sounds wrong to change them on a monthly basis.
Also the transmitters I know run on 3V or 6V Lithium batteries.
But if you need 1,5V I would test a Energizer Lithium battery

joechina
Offline
Last seen: 6 hours 12 min ago
Joined: 03/05/2016 - 08:23
Posts: 128

If you look in the data sheet of the Energizer l92
http://data.energizer.com/PDFs/l92.pdf
You should get more then 60 days runtime

Zebretta
Online
Last seen: 6 min 27 sec ago
Joined: 12/08/2016 - 18:57
Posts: 389
Location: USA

Hi,

These remotes use 1 × 1.5v AAA battery.

Yes I do have some of the Lithium Energizer batteries and they are indeed pretty good batteries.

But they’re not rechargeable. So 1 cycle at 60 days = 60 days run-time for the Energizer Lithium.

But for the NiZn – 300 cycles x 30 days = 9000 days run-time (assuming they only go 300 cycles, even though they claim much more).