Sanyo Eneloop: HR-3UTG won't charge (MH-C9000) @ 'Break-in'

Hi guys,

I have some older Sanyo Eneloop batteries that won't charge on the MH-C9000

I have tried 'Break-In' mode @ 1800 or 1900 capacity, but they still refuse to charge. I get the 'HIGH' reading. (2.64 initial voltage check).
I know - give them a funeral already - but is there anything else I could try?


Marc

Note: I've bought AA & AAA 'Amazon Basics' pre-charged recently (made in Japan), so hopefully they'll have a good run.

I've been able to trick my Maha C9000 into charging batteries with HIGH readings by re-inserting them back into the charger and starting the regular charging process at 1000mA.

It might take a half dozen attempts to get the I.R. down to about 2.09 volts, where the charger can then deal with things.

I got tired of that process and recycled the batteries, but I could get them to charge.

Chris

Marc999 said:

Hi guys,

I have some older Sanyo Eneloop batteries that won't charge on the MH-C9000

I have tried 'Break-In' mode @ 1800 or 1900 capacity, but they still refuse to charge. I get the 'HIGH' reading. (2.64 initial voltage check).
I know - give them a funeral already - but is there anything else I could try?


Marc

Note: I've bought AA & AAA 'Amazon Basics' pre-charged recently (made in Japan), so hopefully they'll have a good run.

Click to expand...

Try another charger (if possible). I have some Eneloops that is showing signs of being worn down but not enough to recycle them yet. I believe the c9000 is way too sensitive on resistance ( granted that i don't have this charger) but these cells had trouble charging on a consumer brand charger as the red light would keep on blinking but charges fine on the mc3000 charger. Heck, even before the mc3000. I had the accu iq-328 charger which has no problems charging really worn out cells. It amazes me as expensive as the c9000 is. That must be really annoying to have cells rejected soon that are probably slightly worn out.

I only have 1 other charger aside from the MH-C9000.

Duracell (4 individual charging slots) that charges @ 550. I could see what happens, but I'm sure the logical thing to do is recycle them.

Thanks for the tips on the continually reinserting when reading 'HIGH' - I tried 3x, but stopped after it didn't work. Also, 'Discharge' of course does nothing @ 400 since there's nothing left in them. Same with Refresh/Analyze.

One more thing that you can try before you do recycle them. This for sure will fix the high issue with your cells. You can temporarily lower the cell's internal resistance drastically by heating them up. ( I don't know why that is but it works! Lol) i used to leave them in the hot sun and then put them in the stubborn charger right away, and ta-da. It charges! Instead of blinking red light, again, i don't know why heat reduces the resistance. Otherwise, recycle them lol.

Don't throw them away. Stick them in a drawer for future use. If you ever get a cheap timed charger, they work great for charging batteries that have high internal resistance.

If your old cells still have decent low-self-discharge, you can still use them for low-current applications like remotes, clocks, etc. If they have poor self-discharge, you can still use them in dim lighting like garden lights or dim flashlights.

You can buy a crappy charger that comes with two crappy 14500 batteries on banggood for $2.25. (Look for "2x Elfeland 3.7V 1200mAh 14500 Li-ion Rechargeable Battery+Dual Smart Charger".) The charger also works with NiMH cells, and it will charge cells with high IR. I've played with it a few times with very old (not Eneloop) cells. Don't trust it with any good cells, though.

And don't use it indoors, either.
P

You could try a deeper discharge of the problem cells by running them in a flashlight until it gets dim (a single cell flashlight is best), then put it on the charger and see if it accepts it.

If that doesn't work, either recycle it or get a dumber charger (my EBL-999 doesn't care about internal resistance, but it's smart enough to not overcharge cells, and it can do 10 at once + 2 9V) and use it in lower current drain applications like a remote. You'll probably find you won't get nearly the mAh that's on the label.

Marc999 said:

...
Thanks for the tips on the continually reinserting when reading 'HIGH' - I tried 3x, but stopped after it didn't work. Also, 'Discharge' of course does nothing @ 400 since there's nothing left in them. Same with Refresh/Analyze.

Click to expand...

Keep in mind mc9000 discharges at 1A PWM, which means the battery cannot sustain 1A draw, regardless if you set it to 400 or 200mA, it just spreads the time so to make it on average e.g. 400mA draw. The battery may be perfectly capable to deliver e.g. 500mA. I know that because I also have a Liitokala Lii500 which does CC charge/discharge (no PWM) and any battery that has been rejected by maha on discharge (return 0 mAh), I was able to get all the charge with Lii500, I really mean ALL the charge! So in fact your batteries may be fully charged regardless what maha say. You may think of maha's discharge like that "how much capacity can I get from the battery if discharged at 1A".
These are pitfalls I consider a downside for maha and all PWM chargers regardless of make if they do not adjust the PWM actual current applied. For that reason, I only use maha for charging mostly and any stubborn batteries are treated by Liitokala. I was able to revive several AAA which delivered 0mAh on Maha (recall 1A PWM discharge performed even if I set it to 200mA) and the cycle mode in maha didn't really do anything for the same PWM reason. I then plugged these batteries in Liitokala and after 3-4 cycles they now deliver almost their full capacity, whilst the 1st or 2nd cycle could yield only up to 100mAh. If I had only maha, I would have thrown away some perfectly good batteries. The fun fact is, all these batteries were accepted by maha (no High shown). So after that experience, for actual rescue of batteries I only consider CC chargers.
Regarding your batteries, initial reading of 2.64V in Maha suggests the batteries cannot really provide any sufficient current, the only viable usage is in very low drain applications (remotes, clocks etc), there isn't anything you can do about high internal resistance. If you want to keep using them in low drain applications, you'll either have to get a true CC charger and charge at low rates or a dumb charger and keep using them till they die completely. When maha indicates High reading, this is a good indication the battery cannot longer provide sufficient current for high drain applications; they will get really hot if used in such devices.

apagogeas said:

this is a good indication the battery cannot longer provide sufficient current for high drain applications; they will get really hot if used in such devices.

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I find that they don't get hot, they just don't deliver the required current. For example, they'll only power a light to a few lumens, even if you put the light on max. Their internal resistance is just too high to deliver much current, even if shorted.

That's probably not the case for cells that are just entering the "high IR" phase of their life, but I've got some cells that come up with 3000-5000 milliohms of internal resistance. But, they still work fine for low-power lights, and in those applications they still have quite a bit of useful capacity. Gotta charge them really slow, though!

WalkIntoTheLight said:

I find that they don't get hot, they just don't deliver the required current. For example, they'll only power a light to a few lumens, even if you put the light on max. Their internal resistance is just too high to deliver much current, even if shorted.

That's probably not the case for cells that are just entering the "high IR" phase of their life, but I've got some cells that come up with 3000-5000 milliohms of internal resistance. But, they still work fine for low-power lights, and in those applications they still have quite a bit of useful capacity. Gotta charge them really slow, though!

Click to expand...

3-5Ω IR is extreme really. I had in mind NiMH which have increased resistance but still useful in moderate applications, probably struggling in higher current usage. I have AA->NP-F converters to drive LED lights, I mostly use in there lower quality cells so even if I overdischarge them I wouldn't care much. They do get very hot and maha registers them as 1.8-2V initial voltage, close to the point of HIGH indication of 2.09V. I have also used Eneloop in there, same power settings and the batteries get just normal hot and the maha initial reading is 1.45-1.6V max. Same behavior in flash usage (very hot vs warm-hot), but there I really need the faster recycle time so I use exclusively eneloop pro in this case.
I'm sure if the battery develops very high IR like yours, the current will be insufficient enough to produce a lot of heat.

Speaking of cells developing high internal resistance. I have 4 AA Eneloops and out of the 4. I believe 2 of them has developed high resistance than the other 2 based on my observation of the performance i am now getting from these cells. I use these cells in a usb power pack to power these usb touch on-off/dimmer led lights. The issue now is when i turn up the brightness, it turns off unexpectedly, even when the cells just came off the charger. After doing a IR test on these cells this is what the charger shows. Are these cells done for? How high is too high to be consider junk cells?


Thanks.

Well, I have several batteries of all types and kinds, my Eneloop Pro are around 30mΩ, good quality used Li-ion 30-60mΩ (brand new was around 20+), well used and old Li-ion 70-120mΩ, Li-ion packs (BP-Ux, NP-Fx) return anything from 200-450mΩ (good to oldest/bad). I use the SkyRC iMax mini to get these values.
So my experience with individual cells (no packs) is anything above 100mΩ for single cells is considered well past its good times. Higher IR means higher voltage drop when used so it is not strange your device cannot get powered up or even if it does, it shuts down instantly. When batteries reach that point, the only viable use is on low drain applications (minimal voltage drop). Just have in mind this IR measurement is very subjective due to the quality of contact made. Try to take a few times the IR reading and each time remove and re-insert the battery to avoid erroneous readings. Your IR is the lowest reading you got (as this got the best connection which isn't part of the actual IR of the battery).

MarioJP said:

when i turn up the brightness, it turns off unexpectedly, even when the cells just came off the charger.

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It makes sense. Your device has a low voltage disconnect, it shuts off when the voltage falls below a certain point. The higher the voltage drop on the cell the less voltage remains for the device. Voltage drop on the cell = internal resistance of the cell * current through the cell. The internal resistance is already too high, even a small increase in current draw (turning up the brightness) will increase the voltage drop and trigger the cuts off. Even with a fully charged cell.

MarioJP said:

Are these cells done for? How high is too high to be consider junk cells?

Click to expand...

It depends on the current draw.

- remotes, portable radios - all OK
- flashlights in LOW/MID - 350mOhm OK, 1350mOhm JUNK
- flashlights in HIGH/TURBO - all JUNK
- high impulse devices (camera flashes) - all JUNK

I personally discard cells with 500+ mOhm internal resistance.

MarioJP said:

After doing a IR test on these cells this is what the charger shows. Are these cells done for? How high is too high to be consider junk cells?

Click to expand...

When you turn up the brightness and the light turns off unexpectedly you can consider the cells junk. You just got a perfect junk-o-meter

Further update on this. Charger now confirms that the 2 cells in question are now junk. This is when trying to charge at 1A (pic on the left). I tried it again, only this time lowered the current to 0.6A and the battery charges, however if you look at the average voltage (pic in the middle and i believe the charger reports an error around 2.2v not too sure on this), you can see how high it is.

As for the discharge test, it is even more interesting as the voltage plummets from 1.4v to the voltage that is on the last 3 pics. I even had to lower the cut-off voltage to get an idea where it stops while discharging at 0.55A on those 2 cells in question. At least the other 2 are sort of ok.

Use these cells in remote i guess.

Got to love the error message though. Battery so poor. This the first time seeing this error lol.

MarioJP said:

[...] As for the discharge test, it is even more interesting as the voltage plummets from 1.4v to the voltage that is on the last 3 pics. I even had to lower the cut-off voltage to get an idea where it stops while discharging at 0.55A on those 2 cells in question.

Click to expand...

That's due to the high IR = 1.35Ω. By Ohm's Law at 0.55A the voltage will drop 1.35Ω * 0.55A = 0.74V, yielding 1.4V - 0.74V = 0.66V, which is very close to the 0.67V shown at the start of your discharge.

Similarly the healthier cell with IR = 367mΩ will drop 0.367Ω * 0.55A = 0.20V yielding 1.4V - 0.20V = 1.20V, which is very close to the displayed 1.21V..