[UnknownVT]

Slot 1: --------------- Slot 2: ------------------ Slot 3: --------------- Slot 4:

724mAh ------------- 742mAh --------------- 784mAh ------------- 869 mAh
95 min --------------- 97 min ----------------- 102min --------------- 114min (these are obviously going up all the time as the units are still attached).
1.43V ---------------- 1.43V ------------------- 1.43V ---------------- 1.44V

R&A only ---------- R&A only ------------Discharge ------------ R&A only
-----------------------------------------------------then R&A

What do you think of these measurements, they have only been through one R&A apart from slot 3, and I did read in the instructions that it is possible to do more than one R&A to bring batteries back to near there original state.
Also thank you for the information to the proper charging amounts for these AAA's.

another quick edit....

the times have not changed at all, my mistake.... (I only thought they would)

slot 1 everything the same
slot 2 everything the same
slot 3 gone up to 145v
slot 4 gone up to 145v

Those readings look pretty good for old rechargeable AAA rated at "1000mAh" -
conservatively most "1000mAh" AAA's do about 800mAh - which is no better than eneloop AAA's.

Glad you realized yourself that the time would not go up any more after the charger says "Done" - ie: done the fast part of the charge -

The Maha/PowerEX C9000 is very kind on batteries - the fast part of the charge - although has multiple end of charge detection strategies - mostly terminates at Vpeak of 1.47v this is before the dV (deltaV) is reached (over complicated: the deltaV detects the slight drop in voltage when the full charge has been reached - by definition (and somewhat pedantically) this is strictly speaking just over-charging the batteries - albeit for a very short duration - the Maha C9000 avoids even that and terminates the charging at about 90% capacity - that is why there is an extra 2 hour top-up charge cycle at 10% of the fast/full charging current = 100mA for a 1000mA charge current for eneloops, to truly reach full capacity)

So your AAA batteries - leave them in for the "extra" 10% top-up charge -
but since they were charged at 1.0C this ought be for only 1 extra hour.

Then if you are curious - allow the batteries to rest for at least 1 hour (to cool down etc.) then put them back in for a discharge cycle at 0.2C = 0.2x1000 = 200mA -until "done" and see the total (dis)charged capacity of each battery.

Then charge them up again at 0.5c = 0.5x1000 = 500mA - until done - leave for the extra 10% top up charge for 2 hours, then they ought to be good to go.

I would do those discharge and charge cycles separately that way there is no rush to catch the reading in any automated cycle like the R&A

---

Last edited by UnknownVT; 09-11-2012 at 11:44 AM.

[sadsack]

They have had a little more than an hour, more like a couple...... (wrong time of day, 7 year old, Daddy daddy every couple of mins) .... bless him.
But I'm going to do that right now, exactly what you have said. I will come back probably a lot later now that the timings will be correct and give you the amounts.
Just printed out the details, be back soon,

thanks UnknownVT.

edit:

I'm also going to try out some Energizer AA 2450mAh NH15 1.2v HR6 that I brought about a year and a half ago, they all show that there is a small amount of charge in them (not totally dead), (originally charged on the Energizer Charger about 7-8 weeks ago), It would be good if these would come back to life, but I Believe that whether I like it or not, these like my other NiMH's may only hold a charge for a very short period of time.
Still on the good side, practice makes perfect.

sadsack
p.s. AAA's are out of the charger and they feel only mildly warm to the touch, actually even the charger doesn't get hot like I thought it might. But I will still leave them for the period you suggested and do them again, per your details.
Yes your quite right, about the R&A, took me nearly 10 mins to make sure I had the correct readings written down.

[UnknownVT]

edit:
I'm also going to try out some Energizer AA 2450mAh NH15 1.2v HR6 that I brought about a year and a half ago,
...but I Believe that whether I like it or not, these like my other NiMH's may only hold a charge for a very short period of time.

Optimal charge for these 2450mAh = 0.5C = 0.5x2450 = 1225mA -
the Maha C9000 cannot do that exactly, so use the nearest 1200mA

Standard discharge (used for measuring remaining capacity) = 0.2C = 0.2x2450 = 490mA
use the nearest 500mA.

Yes, unfortunately high capacity regular NiMH rechargeables after a while just will not hold their charge -
(that's why the eneloop/LSD (Low self-discharge NiMH battery) was invented)

High capacity regular NiMH use very thin materials to cram in all that capacity -
so tend to get damaged more easily -
that includes over-charge, over-heat and even shock, like dropping them -
and only takes one in a set to bring the whole set down -
that's why it is advisable to mark/number individual battery -
not just to be obsessive - but to Id any sub-par ones.

[sadsack]

Update on discharge UnknownVT,

All AAA's were placed back into the same slots. for discharge.

Slot 1: ---------- 773 mAh ------------ 256 Mins --------------- 1.21v

Slot 2: ---------- 764 mAh ------------ 253 mins ---------------- 1.21v

Slot 3: ---------- 762 mAh ------------ 251 mins ----------------- 1.22v

Slot 4: ---------- 803mAh ------------- 266 mins ----------------- 1.20v

I'm going to do the recharge now as your recommendation: I'm going to put them on now, as it's 3.03 am and I'm in need of some sleep so hopefully they should be done in a few hours.
I will post back the info, and then print out the info for the AA's and do the same to them, No reason to R&A them is there.

I also found a small nail file came in handy to give a little roughness to the battery contacts, much better contact.

All the best
sadsack

[UnknownVT]

I will post back the info, and then print out the info for the AA's and do the same to them, No reason to R&A them is there.
I also found a small nail file came in handy to give a little roughness to the battery contacts, much better contact.

Don't file them too much - should just use some contact cleaner -
(DeoxIT is ideal - but isopropyl alcohol will do.)

With the eneloops might be worth fully charging them (including the 2 hour top up charge) - >1hour rest -
then put them through a discharge cycle at 0.2C = 400 mA -
just to see what real capacity they have -
that way you'll know the "health" of each individual cell -
if any are sub-par - then put only those through a R&A cycle -
that's why individual channels are so useful.

[sadsack]

Hi UnknownVT,

Charging and charged states of AAA's.

Set at 500mA

Slot 1: -------- 495 mA
Slot 2: -------- 496 mA
Slot 3: -------- 495 mA
Slot 4: -------- 497 mA

Charged State:
Slot 1: -------- 710 mAh ---------- 95 min -------- 1.45v
Slot 2: -------- 764 mAh ---------- 103 min ------- 1.45v (dropped to 1.44v)
Slot 3: -------- 770 mAh ---------- 102 min ------- 1.45v (dropped to 1.44v)
Slot 4: -------- 835 mAh ---------- 111 min ------- 1.45v (dropped to 1.44v)


-----------------------------------------------------------------------

AA's gone in to discharge, Discharge was within seconds.

Slot 1: ------- 0.93v
Slot 2: ------- 0.94v
Slot 3: ------- 0.93v
Slot 4: ------- 0.93v
Will report back on charged state when done,
sadsack

[sadsack]

Charged state:

Slot 1: ------------- 2302 mAh ----------- 127 min --------------- 1.44v
Slot 2: ------------- 2655 mAh ----------- 147 min --------------- 1.44v --- finished at 1.45v
Slot 3: ------------- 2704 mAh ----------- 149 min --------------- 1.44v -- "" ------ "" 1.45v
Slot 4: ------------- 2533 mAh ----------- 140 min --------------- 1.44v ---- "" ------ "" 1.45v

Thanks for any input ...

sadsack


------------------------

Looking at my readings and what you mentioned before "The Maha/PowerEX C9000 is IMHO the best consumer grade battery charger - I know many will also cite the LaCrosse - but the last time I checked even their top of the line Alpha charger is not that flexible on discharge currents. For a 400mA (=0.2C of eneloop) the follow up charge current is then 800mA - if you want 1000mA charge current - then then discharge has to be at 500mA - not flexible enough to get the ideal.

My C9000 seems to charge up position 1 (left-most) the least - in order of highest to lowest charge mine seems to be 3,2,4,1 - but this is NOT reliable - as it is so dependent on the battery. However position 1 (left-most) seems always to be consistently just a bit lower on my copy."

My first Slot also seems to be the weakest. I haven't really seen a big difference in the other slots, but the 1st is obvious.

---

Last edited by sadsack; 09-12-2012 at 05:45 AM.

[UnknownVT]

My first Slot also seems to be the weakest. I haven't really seen a big difference in the other slots, but the 1st is obvious.

Both your 1000mAh AAA and the 2450mAh AA - look in pretty good state -
of course capacity doesn't say anything about how well/long they will hold their charge -
but at least they seem to have reasonable capacity.

As you've marked/numbered your batteries individually - you can make sure the weakest battery in each set avoids slot #1 - and perhaps put it in either slot #3, or #4 whichever seems the highest charge to you.

If you're really diligent (obsessive?) work out which are the highest/strongest - and put them in the opposite order in the charger's slots......

Now that you've enjoyed those exercises -
your next homework assignment is to
fully charge the eneloop AA's
make sure they have at least 1 hour's rest
then put them through a discharge cycle at 0.2C = 400mAh
and please let us know what you get for the real capacity.

If any seem sub-par - put those only through a R&A cycle and see if that improves them?

Great toy, huh?

[sadsack]

Well you beat me to it UnknownVT,
about an hour ago I took my run down Eneloops out of the camera as they were going to be my next target. This will be set One.

Now there is some juice left in these, (not that the k-x meter means anything but it was on orange, flicking on the liveview made them go to almost depleted after about 15 sec's.
turning off liveview and we go back to orange.

So should I just charge these up first as you posted: charge at 0.5C = 1000mA until done then allow the eneloops to sit in the charger for another 2 hours for the top-up charge.
This may seem a bit of a stupid question, but the part where you mention "sit in charger for another 2 hours" would I correct in saying that this is done by your own means, I.E. alarm on mobile, or whatever you choose to tell you two hours?

Then 1 hours rest,
then put them through a discharge cycle at 0.2C = 400mAh
and please let us know what you get for the real capacity.

Thanks, UnknownVT

sadsack

p.s.
agreed, slot one can have the strongest battery on each change of set.

[UnknownVT]

Now there is some juice left in these, (not that the k-x meter means anything but it was on orange, flicking on the liveview made them go to almost depleted after about 15 sec's.
turning off liveview and we go back to orange.

Not surprising as Live-View, Movies and flash use quite a lot of battery.

I don't use live-view or movies, and hardly ever flash (since I use my $80 p&s for flash work) -
so your shot count is going to be substantially lower compared to my miserly usage.

So should I just charge these up first as you posted: charge at 0.5C = 1000mA until done then allow the eneloops to sit in the charger for another 2 hours for the top-up charge.
This may seem a bit of a stupid question, but the part where you mention "sit in charger for another 2 hours" would I correct in saying that this is done by your own means, I.E. alarm on mobile, or whatever you choose to tell you two hours?
Then 1 hours rest,
then put them through a discharge cycle at 0.2C = 400mAh
and please let us know what you get for the real capacity.

One extra small step if you haven't already started the charge - first discharge those "depleted" eneloops - at 0.2C = 400mA, and record the remaining capacity when "Done" - this way you know how much capacity is left in the eneloops and if any is notably lower than the others. Then rest (>1 hour) before charging at 0.5C = 1000mA.

Yes, I vaguely time the extra 2 hours top-up charge - note the time of start the charge, as the Maha/PowerEX C9000 records the total (fast) charge time, from that we get the "end" time for the extra 2 hours - which is about 4 hours + a few minutes from the initial start.

From Post #7

My charging regime is to always discharge at 0.2C = 400mA until done - then let batteries rest overnight then charge at 0.5C = 1000mA until done then allow the eneloops to sit in the charger for another 2 hours for the top-up charge.

I cycle 3 sets (of 4) - one in camera, carry spare set - one set at home. Before moving the set which was at home to the spare carry set I do a quick top-up charge @ 1000mA - until "done" - before putting them in the bag.

I have now used eneloops in my K-x for almost 58,000 shots with over 49 changes of battery and I average over 1,200 shots per charge with my last two counts at: 1,433 and 1,375 - normally no flash and no live-view or movies.

[sadsack]

Starting right now,

Thanks, UnknownVT

-----------------------------------------------

Discharge measures:

Slot 1: ---- 1344 mAh ------------ 221 min ------------- 1.14v
Slot 2: ---- 1361 mAh ------------ 225 min ------------- 1.13v
Slot 3: ---- 1355 mAh ------------ 222 min ------------- 1.14v
Slot 4: ---- 1348 mAh ------------ 223 min ------------- 1.14v

Switching off now & rest for 1 hour.

[sadsack]

My charging regime is to always discharge at 0.2C = 400mA until done - then let batteries rest overnight then charge at 0.5C = 1000mA until done then allow the eneloops to sit in the charger for another 2 hours for the top-up charge.

------------------------------
It would make more sense for me to do this due to the time the Eneloops finished discharging, (22:30pm) A recharge would be at 11:30 but finishing way before the morning, so I would have no idea as to the finishing time + Top Up.

Do you think it would be a problem for me to do the recharge first thing in the morning, allowing me to have better control over the timings?

[UnknownVT]

Discharge measures:

Slot 1: ---- 1344 mAh ------------ 221 min ------------- 1.14v
Slot 2: ---- 1361 mAh ------------ 225 min ------------- 1.13v
Slot 3: ---- 1355 mAh ------------ 222 min ------------- 1.14v
Slot 4: ---- 1348 mAh ------------ 223 min ------------- 1.14v

Switching off now & rest for 1 hour.

I am assuming these are for the eneloop AAs that you said in Post #24:

about an hour ago I took my run down Eneloops out of the camera as they were going to be my next target. This will be set One.

Now there is some juice left in these, (not that the k-x meter means anything but it was on orange, flicking on the liveview made them go to almost depleted after about 15 sec's.
turning off liveview and we go back to orange.

Look at your own discharge readings -
the charge remaining is 2/3 (67%) the rated capacity of eneloops!

So Orange is nothing to panic about - even if it dips into Red - momentarily
Even on Red there is still about 16.7% capacity left (for me this amounts to about 200 shots...)

It would make more sense for me to do this due to the time the Eneloops finished discharging, (22:30pm) A recharge would be at 11:30 but finishing way before the morning, so I would have no idea as to the finishing time + Top Up.

Do you think it would be a problem for me to do the recharge first thing in the morning, allowing me to have better control over the timings?

Well duh.... of course do the charge cycle when you're awake
or time it such that you're around to catch it at the end of the extra 2 hour top-up cycle.
[it probably doesn't do the batteries much harm if they remain in the charger after the extra 2 hours top-up cycle, once - just don't make a habit of it - as trickle charging eneloops is actually harmful - I try to avoid that if possible - but if one is strapped for time, then a few hours on trickle is not going to be that harmful.
Minimize that "over-time" - by starting the charge as late as possible, like literally just before you go to bed and stop as soon as you're awake - BUT please remember to write down the readings!]

[raider]

The battery man has spoken. Thanks for all these info UnknownVT.

[UnknownVT]

The battery man has spoken. Thanks for all these info UnknownVT.

Thank you - that is most kind of you.

I merely read a lot and gleaned a lot of my information from CPF -
Flashlight Electronics - Batteries Included
and credit where credit is due - especially the threads/posts from SilverFox -
like:
Maha MH-C9000 Wizard One Charger

NiMh Battery Shoot Out

Eneloop Self Discharge study

An informal look at the Sanyo NC-MQN06U - Charging in Pairs

Here's a useful reference thread:

Flashlight Electronics - Batteries Included - Threads of Interest

I also had a rambling thread -
not very well organized - since I was experimenting as I went along:
eneloop vs. Kodak Pre-Charged Voltage Maintenance
using the Pentax K100D as the test bed -
so it is very relevant here for Pentax dSLRs and battery meter levels -
because of the dis-organized nature I did do a Summary of results in Post #57
(of course I did all this before owning the Maha/PowerEX C9000 -
things probably would have been a lot easier and possibly clearer cut if I had)