Titanium Charger & NiCd Problems

[jayflash]

The new Titanium MD3000 charger lasted only a few days before two of the charging bays failed. About 1/3 of the 20 Titanium Innovation AA, "High Discharge Rate", NiCd cells, I ordered, have only ~1/2 of rated capacity after 4 - 5 break in cycles. The eight 3.2Ah C size NiCd have only 2/3 capacity at only a 200mA load. The 7000mAh D cells have about 5000mAh capacity at 200mA. Of the big batch of cells, I ordered, only the sub-C are close to capacity.

I've already received an RMA, but what a disappointment and waste of my time. Do you think a few more cycles are needed to bring the cells up to capacity? Most of the AA cells showed immediate voltage suppression, going below 1.2 volts at only a 200mA load.

The reason I ordered NiCds rather than NiMH cells is due to the nature of their use. Some will be used to near exhaustion or kept on trickle charge. Anybody else have experience with "Titanium Innovations"?

 

[Black Rose]

I have some of the Titanium Innovations Power Enduro LSD NiMh AA & AAA cells.

The AA cells needed somewhere around 15 charge/discharge cycles before they started to come to life. Capacity wise, they are all 12 to 17% below the labelled capacity according to my Maha C9000.

Even though they are not where I would expect them to be capacity wise, their LSD capabilities are very good.

 

[MattK]

Sorry to hear about these issues - I'm sure our C/S will take good care of you. Especially with regards to the charger - we've had almost no returns on the MD-3000's.

There's a few things that leap to mind here:

Firstly 4-5 break in cycles isn't enough - proper formation can take twice as many cycles as that.

Secondly, I am a bit confused as the the problems with the AA's; those cells are very fresh having arrived perhaps a month ago. I'm not sure what discharge and test methodology you're using but charge and discharge rates will play a major role - do you have the 900mah HD cells or the standard discharge 1200mah cells?
Either way the MD3000 is 'too much' charger for these cells; the capacity ratings are calculated using .2C charge and discharge rates , to grossly oversimplify. The MD-3000 has a 1.7A charge rate which means, depending on which battery you have, that you're hitting those NiCd's with 1.5C or 2C charge rates so it is not suprising they don't seem to make their specified capacity; if you don't use them within spec you cannot expect them to perform within spec. FYI, I just pulled the factory spec for the 900mah HD cells and it's standard charge rate .2C (180mah), normal charge rate .4C (360mah) and quick charge .5C (450mah).

There's some excellent basics on batteries; charging, discharging, chemistry etc at these two sites:
http://www.gpina.com/pdf/NiCd.pdf
http://www.batteryuniversity.com/

See this from the GP PDF:
3.2 Charging Method
Like NiMH, the main concern in charging a NiCd
battery is the build-up of temperature and internal
pressure due to high overcharge rates. As previously
mentioned, the cell design applies the concept of
oxygen recombination in lowering the battery's
internal oxygen level during standard charging.
However, if the cell is subjected to severe charging
conditions (such as overcharging at a current rate
over 1C), the rate of oxygen evolution from the
positive electrode increases rapidly, exceeding the
recombination reaction rate. As the oxygen
recombination reaction is exothermic, this results in
excessive oxygen pressure and increased
temperature. The excessive pressure will then be
released through the safety vent causing a reduction
in the cell electrolyte; the excessive heat will
eventually degrade the cell's internal contents. These
two factors are considered to be the major limitations
to the battery's service life. For this reason, charge
control is very important in battery charging. GP
NiCd cylindrical cells are designed to be able to
charge up to 1C rate.

I'm guessing that it was only the thermal protection circuit in the MD-3000 that kept these cells from venting and leaking.

 

[jayflash]

Thanks for the reply, Matt. I didn't mention where I purchased these items because I've got complete confidence the problems will be resolved. Our past transactions were all flawless and the products performed as advertised.

The NiCd AA cells are the 900mAh "5C" discharge. I first charged all the cells from that order @ 200mA in a LaCrosse BC-900 (confirmed specs & reliability). They were all discharged @ 100mA after subsequent charges. I did a few (4 - 5) more 500 & 700mA charge/100mA discharge cycles.

Most of them hold up well, now, @ 350mA discharge and meet (close) the 900mA spec. A few still have low (300mAh) capacity and a several more show about 500mAh, so I'll run more cycles on them.

Perhaps all the cells are quite fresh and in need of more cycling. I've had good service from cell purchased from Matt, in the past, which are now several years old.

The MD3000 was only used with the C & D NiCds. I wouldn't even charge my "Duraloops" or ROV Hybrids at the MD's ~1700mA rate. The charger performs perfectly on two channels and I confirmed the chg/discharge rate with an accurate meter.

 

[MattK]

Sure thing and thanks for your faith and confidence. it will not be misplaced.

I think a few more cycles should do it - it's not unusual for fresh NiCd cells to need a bunch of forming charges

We'll get the MD-3000 replaced and take it from there - I'm sure we can make sure that you're satisfied.

 

[jayflash]

Hopefully I jumped the gun with my concern, but I was wondering about any other experience. There probably aren't too many people buying NiCds anymore and this forum is one place, other than an RC forum, to get feedback.

The charger is probably victim of my close proximity. :sigh: The last stereo system I assembled (~$5000) had a bad preamp, remote control and one of two woofers in each speaker. This was decent stuff: Adcom and Paradigm. My new washing machine developed a problem that three different service techs couldn't fix. After almost a year of new parts the company replaced my Fridgedaire front loader. My HDS U60 was returned for repair right after I got it several years ago. PT just replaced my Yukon HL. The list continues ... The new MD3000 didn't stand a chance!

I must have used up my luck, years ago, when servicing industrial and consumer electronics. Often, the malfunction would disappear in my presence. Things seem to even out.

I'll continue to do several more cycles at a low 100mA discharge and 500mA charge rate for the AA cells, with the BC-900. I'm limited to the ~1.7mA rate for the two good MD3000 slots and a bit less for a single slot on my CCrane, for the C & D cells. I realize a .5C - 1C charge rate is best, but that's all I've got.

 

[MattK]

LOL - damn you're cursed!