Can you top off a K-3 battery?

Shakey · 12-28-2014, 06:32 PM

I searched for this topic but did not find anything...I have Pentax batteries for my K-3. If they are not completely discharged can I top them off to fully charge them or will I be lessening the life of the battery?
Thanks

amoringello · 12-28-2014, 06:49 PM

Current rechargeable battery tech does not require complete drain.
Charge them any time you want. I always charge them regardless of how drained they are before I go out for a day's shooting.

calsan · 12-28-2014, 06:57 PM

I've been doing that with my K10d since December 2006 and the batteries still hold a good charge. Same with k7 and k3. I think the older NiCad batteries required draining, but these are Lithium Ion. Ideally, they should be charged to less than 80% for storage, but I don't think that would make much more than a small percent in longevity over many years of use.

ppppsssstttt · 12-28-2014, 07:15 PM

i've seen conflicting/inconclusive reports/opinions regarding topping off. while it's true that lithium ions don't suffer from memory effect like nicads, some people will say that continually topping off from ~85%(?) - 100% will decrease the longevity of the battery. it's the top couple of percent that's tricky to keep charging over and over again. any sort of discharge/recharge cycle is a cycle, and it's the # of cycles that matters. if you look at the curves when a battery is charged, it's usually pretty fast from 0-85% and slows down for the last ~15%.

in practice, i don't know how much of a difference we can tell over the course of a battery's life. i wouldn't worry too much about it because the battery you're using is pretty common. if it dies, there are plenty out there to replace it. i'd worry more if it were a device that has a less common battery, or a device with a non-user replaceable battery, or if pentax decides to go with a different battery for the future cameras. you might be worrying about having a couple of extra outings if you don't top off your battery all the time while risking a dead battery at the end of the day. 6 of 1 half dozen of another

Adam · 12-28-2014, 07:42 PM

Originally posted by Shakey

I searched for this topic but did not find anything...I have Pentax batteries for my K-3. If they are not completely discharged can I top them off to fully charge them or will I be lessening the life of the battery?
Thanks

The K-3's battery charges so slowly that I think topping it off isn't harmful, especially if you only do it once in a while.

cbope · 12-29-2014, 11:42 AM - **1 Like**

Originally posted by ppppsssstttt

any sort of discharge/recharge cycle is a cycle, and it's the # of cycles that matters.

Sorry, I'm going to disagree on that one. A cycle is not a cycle and in fact, more recent studies have proven modern Li-Ion batteries start losing their charge capacity when exposed to full charge/discharge cycles on a regular basis quicker than batteries that are charged more irregularly or are topped off when needed.

The biggest contributor to cell death seems to be heat, and charging a nearly empty Li-Ion to full charge dumps a whole lotta heat into the battery. Top-off charges put far less heat into the cells and do it over a shorter time period.

I do agree it's not healthy to continually charge them from 97% to 100% full. By topping off I mean at least 75-80% capacity still remains. I rarely drain my Pentax D-LI90's below 50% and I am still running the original that came with my K-5 after 3 years and no sign of reduced capacity that I can notice.

Another no-no with Li-Ion is draining them near empty and leaving them in that state over a period of time without charging them. The cells can actually flip polarity under this condition.

ppppsssstttt · 12-29-2014, 12:25 PM

Originally posted by cbope

Sorry, I'm going to disagree on that one.

no problem, I've never quite bought into that idea either. that's just what i've read in the past.

Shakey · 12-29-2014, 12:48 PM

Thanks for the info..especially about leaving the battery uncharged for a long period.

ppppsssstttt · 12-29-2014, 01:34 PM

Originally posted by Shakey

Thanks for the info..especially about leaving the battery uncharged for a long period.

actually, that's a really good point. i've left a device uncharged for a long time and i had to throw it away because the battery was dead. it was a special sized lithium battery with no replacement parts, not even from ebay. the closest i could get was a 100 piece order from china.

12-28-2014, 06:32 PM	#1
Shakey Senior Member Join Date: May 2014 Location: Wisconsin, USA Posts: 211	Can you top off a K-3 battery? I searched for this topic but did not find anything...I have Pentax batteries for my K-3. If they are not completely discharged can I top them off to fully charge them or will I be lessening the life of the battery? Thanks

12-28-2014, 07:42 PM	#5
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,593	Originally posted by Shakey I searched for this topic but did not find anything...I have Pentax batteries for my K-3. If they are not completely discharged can I top them off to fully charge them or will I be lessening the life of the battery? Thanks The K-3's battery charges so slowly that I think topping it off isn't harmful, especially if you only do it once in a while. Adam PentaxForums.com Webmaster (Site Usage Guide \| Site Help \| My Photography) PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

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12-28-2014, 06:49 PM	#2
amoringello Veteran Member Join Date: May 2008 Location: Virginia, USA Photos: Gallery Posts: 1,562	Current rechargeable battery tech does not require complete drain. Charge them any time you want. I always charge them regardless of how drained they are before I go out for a day's shooting.

12-28-2014, 06:57 PM	#3
calsan Pentaxian Join Date: Nov 2008 Location: Perth, Australia Photos: Gallery Posts: 1,548	I've been doing that with my K10d since December 2006 and the batteries still hold a good charge. Same with k7 and k3. I think the older NiCad batteries required draining, but these are Lithium Ion. Ideally, they should be charged to less than 80% for storage, but I don't think that would make much more than a small percent in longevity over many years of use.

12-28-2014, 07:15 PM	#4
ppppsssstttt Senior Member Join Date: Dec 2010 Location: Massachusetts Posts: 152	i've seen conflicting/inconclusive reports/opinions regarding topping off. while it's true that lithium ions don't suffer from memory effect like nicads, some people will say that continually topping off from ~85%(?) - 100% will decrease the longevity of the battery. it's the top couple of percent that's tricky to keep charging over and over again. any sort of discharge/recharge cycle is a cycle, and it's the # of cycles that matters. if you look at the curves when a battery is charged, it's usually pretty fast from 0-85% and slows down for the last ~15%. in practice, i don't know how much of a difference we can tell over the course of a battery's life. i wouldn't worry too much about it because the battery you're using is pretty common. if it dies, there are plenty out there to replace it. i'd worry more if it were a device that has a less common battery, or a device with a non-user replaceable battery, or if pentax decides to go with a different battery for the future cameras. you might be worrying about having a couple of extra outings if you don't top off your battery all the time while risking a dead battery at the end of the day. 6 of 1 half dozen of another

12-29-2014, 11:42 AM - 1 Like	#6
cbope Veteran Member Join Date: Dec 2011 Location: Helsinki Posts: 664	Originally posted by ppppsssstttt any sort of discharge/recharge cycle is a cycle, and it's the # of cycles that matters. Sorry, I'm going to disagree on that one. A cycle is not a cycle and in fact, more recent studies have proven modern Li-Ion batteries start losing their charge capacity when exposed to full charge/discharge cycles on a regular basis quicker than batteries that are charged more irregularly or are topped off when needed. The biggest contributor to cell death seems to be heat, and charging a nearly empty Li-Ion to full charge dumps a whole lotta heat into the battery. Top-off charges put far less heat into the cells and do it over a shorter time period. I do agree it's not healthy to continually charge them from 97% to 100% full. By topping off I mean at least 75-80% capacity still remains. I rarely drain my Pentax D-LI90's below 50% and I am still running the original that came with my K-5 after 3 years and no sign of reduced capacity that I can notice. Another no-no with Li-Ion is draining them near empty and leaving them in that state over a period of time without charging them. The cells can actually flip polarity under this condition.

12-29-2014, 12:25 PM	#7
ppppsssstttt Senior Member Join Date: Dec 2010 Location: Massachusetts Posts: 152	Originally posted by cbope Sorry, I'm going to disagree on that one. no problem, I've never quite bought into that idea either. that's just what i've read in the past.

12-29-2014, 12:48 PM	#8
Shakey Senior Member Join Date: May 2014 Location: Wisconsin, USA Posts: 211 Original Poster	Thanks for the info..especially about leaving the battery uncharged for a long period.

12-29-2014, 01:34 PM	#9
ppppsssstttt Senior Member Join Date: Dec 2010 Location: Massachusetts Posts: 152	Originally posted by Shakey Thanks for the info..especially about leaving the battery uncharged for a long period. actually, that's a really good point. i've left a device uncharged for a long time and i had to throw it away because the battery was dead. it was a special sized lithium battery with no replacement parts, not even from ebay. the closest i could get was a 100 piece order from china.

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