Uniden cordless phone battery life?

Muse

Lifer
Jul 11, 2001
22,381
638
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Santa came early this year. For some time I've been wanting one or two more cordless speakerphones for my house. I got a Panasonic KX-TC1703B via a Hot Deals thread in 2002 and when it had a problem, Panasonic sent me a Panasonic KX-TGA224F to replace it. The KX-TGA224F is a 2.4 GHz cordless speakerphone and easily my favorite around the house. So, I was contemplating getting a couple more similar and thought if I get a holiday check, I'll buy them.

However, yesterday biking home from the gym I spotted a box on the sidewalk with wires sticking out and I doubled back. The box was for a 4 handset Panasonic system, but when I got it home it turned out that inside was a Uniden system, evidently just replaced by the Panasonic system. Thanks, Santa! I've seen similar Uniden systems selling in Costco for a long time but figured them to be inferior to Panasonic, really only based on posts from years ago, many in the thread mentioned above. One of the handsets appeared to not be working and putting it on a charger, it wasn't showing any life. Inspecting the battery pack I realized that it hadn't been properly attached, and attaching it brought it back to life. I have to wonder if the owner mistakenly assumed that one of their handsets was no longer functional and replaced the whole system therefore.

Well, this is a Uniden TRU9280-3 5.8 GHz system, with answering machine, 3 cordless speakerphones. I downloaded and printed the manual and have read most of it and am going "man, I didn't know what I was missing!" Until now I had a digital answering machine, a corded speakerphone, the Panasonic KX-TGA224F cordless speakerphone mentioned and an ATT cordless without speakerphone. This Uniden system will replace all that and have an integrated system and the instructions make it clear that for the most part this thing is very well thought out and intuitive, no doubt the result of several life cycles for their cordless phone systems. However, I came to the statement about 2/3 into the manual that the batteries (NiMH) for the handset units only last about a year! "With average use, your phone's battery should last approximately one year." This is dumbfounding to me. I think my original Panasonic had the battery die (NiCD, probably), and I'd babied it, not leaving it on the cradle and thinking that the batteries would last longer if not topped up constantly. I'd done this because of a few cautionary statements in the original Panasonic's manual. That phone IIRC didn't last so much as a year. Since, I've left my cordless phones on their cradles and none have had their batteries die, after several years. The ATT cordless must be a dozen years old and still works. It has NiCd batteries. My Panasonic has NiMH batteries. Will I really need to replace these Uniden NiMH batteries every year? That seems preposterous.
 

Eli

Super Moderator | Elite Member
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Oct 9, 1999
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Keeping a battery near 100% State of Charge without overcharging is paramount to longevity, whether it be NiCd, NiMH, lead acid or any other rechargeable battery.

Try not to let it get below 50% SoC and it should last longer than a year.

They're probably just covering their asses. I would say 1 year is the minimum amount of time the battery should last.
 

spidey07

No Lifer
Aug 4, 2000
65,481
2
76
Maybe that's why they tossed it? I've noticed that phone batteries don't last nearly as long as they used to.
 

marvdmartian

Diamond Member
Apr 12, 2002
5,513
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Maybe it's just a safe statement made by the company? I don't use my phones often, but I have the Uniden 5.8GHz cordless system with cordless base station and 2 remote handsets (only one phone jack in my apartment, so this was the best type of system for me). The system is almost 2 years old now, and no problems with battery life. :)
 

Muse

Lifer
Jul 11, 2001
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Originally posted by: Eli
Keeping a battery near 100% State of Charge without overcharging is paramount to longevity, whether it be NiCd, NiMH, lead acid or any other rechargeable battery.

Try not to let it get below 50% SoC and it should last longer than a year.

They're probably just covering their asses. I would say 1 year is the minimum amount of time the battery should last.
I guess the thing to do then is to keep the handsets on their chargers. Like I say, I didn't do this with my first Panasonic (thinking that the batteries would last longer if I made them go through near complete cycling, and I think this was often recommended at least in those days with NiCD's) but that's the one whose batteries died. When I did a warranty replacement on the phone, Panasonic, having left my model behind, sent me one with NiMH batteries and I've pretty much kept it on the charger and it's been ~5 years now, and it's still working OK AFAIK.

Yes, their statement may be to deflect possible complaints from owners ("cover their asses").

Originally posted by: marvdmartian
Maybe it's just a safe statement made by the company? I don't use my phones often, but I have the Uniden 5.8GHz cordless system with cordless base station and 2 remote handsets (only one phone jack in my apartment, so this was the best type of system for me). The system is almost 2 years old now, and no problems with battery life. :)
Do you keep your handsets on the charging stands when not in use?
 

Jeff7

Lifer
Jan 4, 2001
41,602
10
76
Originally posted by: Eli
Keeping a battery near 100% State of Charge without overcharging is paramount to longevity, whether it be NiCd, NiMH, lead acid or any other rechargeable battery.

Try not to let it get below 50% SoC and it should last longer than a year.

They're probably just covering their asses. I would say 1 year is the minimum amount of time the battery should last.
Except li-ion.

Those things lose capacity just by existing.

And I think they're best kept at 50% charge, but I could be wrong on that.
Li-ions are crazy critters.


NiMHs should be good for 1000 charge/discharge cycles.

Two things that could kill them early:
- A cheap charger, which is likely in a cordless phone like that.
I had a phone that was in the same price range as that Panasonic, and the battery pack was always warm. That should only happen when the batteries are being charged at a fairly rapid rate. Overcharging is a great way to kill a battery.
I also had a Dustbuster which had a simple charging circuit: A resistor and a diode hooked to a regular DC power supply. That was it. Those things didn't even last 3 months. I replaced the NiCads with two NiMH cells and got it a real charger. It's well over a year old and still going strong.

- Cheap batteries. I have had terrible luck with Chinese NiMH batteries. They tend to have poor discharge curves, lower-than-normal voltages, or else they simply die after less than 100 cycles, showing a terminal voltage of <0.1V with greatly diminished capacity.
Made in Japan Sanyo NiMH cells: :heart: And their Eneloops are simply excellent.

 

mugs

Lifer
Apr 29, 2003
48,903
9
81
My Uniden phone batteries have lasted much longer than a year.

You could replace it with a different brand of battery if you're worried.
 

dandruff

Golden Member
Jan 28, 2000
1,402
1
81
we ahve a uniden set as well .. color lcd screen on all 4 handsets ... and even with all that drain, batteries lasted 3 yrs (thats a lot less compared to panny, i know); but bought new batteries off ebay (not original or even good aftermarket like lenmar) .. just got no-name batteries from a seller named "batterygalaxy" for $3 shipped each (MS Live Cashback) ... and they are working beautifully ... hth!
 

Rubycon

Madame President
Aug 10, 2005
17,770
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Originally posted by: Jeff7
...meGaSnip...
Made in Japan Sanyo NiMH cells: :heart: And theri Eneloops are simply excellent.

Pana-Sany now. :laugh:

Japanese cells > Chinese cells. SOME CN li-ions are actually pretty good but <danger!> they are naked, unprotected and the end user MUST have some kind of protection or they may face an eruption of hazardous materials, release of fire/flaming balls, and destruction of property. :Q

 

OFFascist

Senior member
Jun 10, 2002
987
0
0
For house phones I personally go with corded phones. I use my cell phone as my primary and only use the house phone for my DSL or faxing. So I dont need to be wasting electricty to charge a battery on a phone I rarely use also if the power ever goes out with a corded phone atleast I could make a phone call on it.
 

dman

Diamond Member
Nov 2, 1999
9,111
0
0
It's getting cheaper to replace the phones than the batteries, $20/pack vs $30-50 for a close-out model new phone.
 

Jeff7

Lifer
Jan 4, 2001
41,602
10
76
Originally posted by: Rubycon
Pana-Sany now. :laugh:

Japanese cells > Chinese cells. SOME CN li-ions are actually pretty good but <danger!> they are naked, unprotected and the end user MUST have some kind of protection or they may face an eruption of hazardous materials, release of fire/flaming balls, and destruction of property. :Q
Mmmmm, I love battery talk.
:D


 

SonicIce

Diamond Member
Apr 12, 2004
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Originally posted by: Jeff7
Originally posted by: Rubycon
Pana-Sany now. :laugh:

Japanese cells > Chinese cells. SOME CN li-ions are actually pretty good but <danger!> they are naked, unprotected and the end user MUST have some kind of protection or they may face an eruption of hazardous materials, release of fire/flaming balls, and destruction of property. :Q
Mmmmm, I love battery talk.
:D
LOL
 

Muse

Lifer
Jul 11, 2001
22,381
638
126
Originally posted by: Jeff7
Originally posted by: Eli
Keeping a battery near 100% State of Charge without overcharging is paramount to longevity, whether it be NiCd, NiMH, lead acid or any other rechargeable battery.

Try not to let it get below 50% SoC and it should last longer than a year.

They're probably just covering their asses. I would say 1 year is the minimum amount of time the battery should last.
Except li-ion.

Those things lose capacity just by existing.

And I think they're best kept at 50% charge, but I could be wrong on that.
Li-ions are crazy critters.


NiMHs should be good for 1000 charge/discharge cycles.

Two things that could kill them early:
- A cheap charger, which is likely in a cordless phone like that.
I had a phone that was in the same price range as that Panasonic, and the battery pack was always warm. That should only happen when the batteries are being charged at a fairly rapid rate. Overcharging is a great way to kill a battery.
I also had a Dustbuster which had a simple charging circuit: A resistor and a diode hooked to a regular DC power supply. That was it. Those things didn't even last 3 months. I replaced the NiCads with two NiMH cells and got it a real charger. It's well over a year old and still going strong.

- Cheap batteries. I have had terrible luck with Chinese NiMH batteries. They tend to have poor discharge curves, lower-than-normal voltages, or else they simply die after less than 100 cycles, showing a terminal voltage of <0.1V with greatly diminished capacity.
Made in Japan Sanyo NiMH cells: :heart: And their Eneloops are simply excellent.
Yep, Lithium Ion rechargables are different. I try to never charge them to peak capacity. They deteriorate fastest at peak charge. They are best stored at 40% capacity in the refrigerator and that's where my laptop battery is right now, my camcorder's batteries too, all put in there at ~40% charge because I don't use them often. When I charge my cell phone I am careful not to charge it to the peak. I never intentionally leave it on the charger and forget about it, but it's happened a few times. At such times I'm sure to leave the phone on so it discharges. I believe that my cell phone makes periodic automatic calls into the network to check on time synch, maybe other things. I don't know how else to account for the fact that the phone's battery discharges so quickly when on even if I don't use it. Edit:I guess it also uses a fair amount of power just determining how good a signal it's getting/providing the network. I guess I'm doing pretty well with my cell phone battery though because I've had it over 4 years and it's still operational. When I got the phone I heard that the battery would last a year or two.

The chargers with this Uniden system appear to be not bad. The critical thing is that they don't charge too quickly. A 15-20 hour first time charge is recommended. I have to think that the charge rate is below 0.1C. I'm referring to the rate where a discharged cell would reach full charge in 10 hours. The satellite chargers for this Uniden system are rated at 4 watts, so that would seem to be close to trickle rate, which is best. The downside would be that it doesn't lessen the charge when the batteries are topped (AFAIK, I don't actually know one way or the other how that apparently simple charger is designed), but if the rate is low enough it wouldn't matter. This is more true of NiCDs than NiMH, though.

I try to buy really really good rechargable batteries. Had too many bad experiences with substandard batteries. Prepacked in devices, I have little control of that, though.

Regarding Sanyo and eneloops, I heard on the news maybe yesterday that Panasonic is buying them, and it was opined that it was to get ahold of their superior rechargable battery business.


 

Muse

Lifer
Jul 11, 2001
22,381
638
126
Originally posted by: OFFascist
For house phones I personally go with corded phones. I use my cell phone as my primary and only use the house phone for my DSL or faxing. So I dont need to be wasting electricty to charge a battery on a phone I rarely use also if the power ever goes out with a corded phone atleast I could make a phone call on it.
It's for that reason that I will retain my corded phone after I swap out my current systems with this Uniden system. I live only a couple of miles from a major earthquake fault (the Hayward Fault), which has been having a major quake just about every 140 years. It's been just about exactly 140 years since the last one. I might need that corded phone any time. I still haven't set up my Uniden system, busy today.

 

Jeff7

Lifer
Jan 4, 2001
41,602
10
76
Charging at 1C = charging at the nominal discharge rate.

So a 2Ah battery would be taking a charge of 2A at 1C.

You meant to say 0.1C instead of 10C.


And I think a good charger is one that uses some -deltaV detection or some such thing - some circuitry that monitors the battery's voltage and adjusts the charging rate accordingly. But of course such circuitry adds expense, which is a bad thing for manufacturers.



Originally posted by: Muse
Regarding Sanyo and eneloops, I heard on the news maybe yesterday that Panasonic is buying them, and it was opined that it was to get ahold of their superior rechargable battery business.
Hopefully they don't screw over the quality. Makes me wish I had the money laying around now; I'd replace half of my NiMH stock with Eneloops now, just in case they do decide to cheap out and send the quality to hell.


 

Muse

Lifer
Jul 11, 2001
22,381
638
126
Originally posted by: Jeff7
Charging at 1C = charging at the nominal discharge rate.

So a 2Ah battery would be taking a charge of 2A at 1C.

You meant to say 0.1C instead of 10C.

And I think a good charger is one that uses some -deltaV detection or some such thing - some circuitry that monitors the battery's voltage and adjusts the charging rate accordingly. But of course such circuitry adds expense, which is a bad thing for manufacturers.

Originally posted by: Muse
Regarding Sanyo and eneloops, I heard on the news maybe yesterday that Panasonic is buying them, and it was opined that it was to get ahold of their superior rechargable battery business.
Hopefully they don't screw over the quality. Makes me wish I had the money laying around now; I'd replace half of my NiMH stock with Eneloops now, just in case they do decide to cheap out and send the quality to hell.
Thanks for correcting me on the 0.1C. I edited my post to correct my mistake.

Yes, deltaV. I don't know whatall is in the chargers but what I see is what looks like a transformer, but maybe isn't. Lately I've been seeing wall warts that are smaller than the larger square ones we used to get. They have rounded corners and they use less energy by quite a bit. Is it possible that deltaV technology is built into some of these?

Regarding eneloops taking a nose dive in quality, I sort of doubt that this is going to happen. Panasonic AFAIK is still Matsushita and they are one of the very best Japanese electronics outfits. For years Matsushita products have had a great reputation for reliability and quality. That is unless they've tailed off, but if they have, it's news to me.
 

Muse

Lifer
Jul 11, 2001
22,381
638
126
Originally posted by: Rubycon
Originally posted by: Jeff7
...meGaSnip...
Made in Japan Sanyo NiMH cells: :heart: And theri Eneloops are simply excellent.

Pana-Sany now. :laugh:

Japanese cells > Chinese cells. SOME CN li-ions are actually pretty good but <danger!> they are naked, unprotected and the end user MUST have some kind of protection or they may face an eruption of hazardous materials, release of fire/flaming balls, and destruction of property. :Q
I thought that by law the lion batteries had to have protection built into them, or maybe I'm thinking of the chargers. I had a conversation with a pretty technically savvy guy on the phone about it.

 

Muse

Lifer
Jul 11, 2001
22,381
638
126
Originally posted by: spidey07
Maybe that's why they tossed it? I've noticed that phone batteries don't last nearly as long as they used to.
I read your post with skepticism, Spidey, but I have to think now that you may have hit the nail squarely on the head. This morning, less than 48 hours after finding this system, and about 36 hours after fully charging one of the handsets I found all three handsets completely discharged. :Q Their inability to hold a charge may well be the reason why the system was out on the sidewalk. Well, I'll keep them on the charging stands and see if I have problems (i.e. phone dieing in the middle of a conversation!). If I do, I guess I'll be in the market for replacement batteries. I hope not.
 

Rubycon

Madame President
Aug 10, 2005
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Originally posted by: Muse


I thought that by law the lion batteries had to have protection built into them, or maybe I'm thinking of the chargers. I had a conversation with a pretty technically savvy guy on the phone about it.
As a rule OEM cells (specifically made for design into a product for an end user) will NOT have protection - i.e. naked cells, unprotected cells, etc. Cells made for the end user (flashlights, for example) will have basic protection to guard against shorting, over and under discharging. The common 18650 cell, for example having a capacity around 2.6Ah will be around 2Ah or so with protection since the pcb takes up space and the cell can is shorter.

These cells are commonly used in notebook packs arranged in SP for capacity desired voltage for the computer. The protection, health and monitoring components are integrated into the pack but not the discrete cell.

 

tk149

Diamond Member
Apr 3, 2002
7,258
1
0
I bought a refurbished Uniden cordless about 3 years ago, and it's still going strong.

Luck of the draw?
 

Jeff7

Lifer
Jan 4, 2001
41,602
10
76
Originally posted by: Muse
I read your post with skepticism, Spidey, but I have to think now that you may have hit the nail squarely on the head. This morning, less than 48 hours after finding this system, and about 36 hours after fully charging one of the handsets I found all three handsets completely discharged. :Q Their inability to hold a charge may well be the reason why the system was out on the sidewalk. Well, I'll keep them on the charging stands and see if I have problems (i.e. phone dieing in the middle of a conversation!). If I do, I guess I'll be in the market for replacement batteries. I hope not.
You charged them and then left the phones sitting off of their cradles?

If that's the case, I'm not too surprised. The handsets use power while sitting idle; some have displays which will use some electricity, and at the very least, they have to be listening for the Locate Handset signal from the base, should you wish to figure out where you left the darned thing sitting.


Is it possible that deltaV technology is built into some of these?
Possible, yes. I wouldn't know how to check though.


Regarding eneloops taking a nose dive in quality, I sort of doubt that this is going to happen. Panasonic AFAIK is still Matsushita and they are one of the very best Japanese electronics outfits. For years Matsushita products have had a great reputation for reliability and quality. That is unless they've tailed off, but if they have, it's news to me.
That's good to know.:)

 

Red Squirrel

No Lifer
May 24, 2003
52,328
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www.uovalor.com
We have a uniden cordless set (2 phones, 1 main base and 1 charger base) we put it in the base most of the time after each use. I don't remember when it was bought but been at least 3 years.
 

Eli

Super Moderator | Elite Member
Super Moderator
Oct 9, 1999
50,425
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Originally posted by: Jeff7
Originally posted by: Rubycon
Pana-Sany now. :laugh:

Japanese cells > Chinese cells. SOME CN li-ions are actually pretty good but <danger!> they are naked, unprotected and the end user MUST have some kind of protection or they may face an eruption of hazardous materials, release of fire/flaming balls, and destruction of property. :Q
Mmmmm, I love battery talk.
:D
Bwhaha!!!

:D
 

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