David Gladwin

Last Sunday I had a TX battery voltage alarm whilst starting a model for the 8th flight of the day. Thought it strange as the voltage had been at 11.3, normal, after taking it off charge that morning.

Getting home I charged overnight, voltage came up to 11.2 but rapidly decayed to 10.2 and ten minutes later died completely.

A new battery arrived this morning and on dismantling the case, the original battery had considerable brown, negative, wire corrosion and powder on the negative terminals. It was purchased in June 04 in one of two new 10Xs I bought then. The battery in the other 10X was changed a year ago as a precaution and the original battery from that Tx still looks fine and passes a capacity check. and ii used a lot in my bench-only 10X. !

I have several JR batteries years old (not used for flight) which still show no sign of this corrosion. so after 4 years this seems odd.

I see the batteries in my new 12Xs are identical in shape etc and are NiMh of 2200 Mah and appear interchangeable with the 10x battery.

I know nothing of the chemistry of this corrosion, but perhaps NiMh are not subjct to this problem.

Anyway may I suggest you do a visual check on your batteries to ensure you are not experiencing this problem, it MIGHT save you a jet.

Regards, David Gladwin.

tothemax

Check out this thread.When I tore the JR packs apart I discovered a similar corrosion problem.They weren't very old.
http://www.rcuniverse.com/forum/m_76...tm.htm#7682988

craigdyer

Hi To All

The black wire effect only happens to Ni Cads when a cell dies or is over discharged causing cell reversal...Some electrolyte creeps out or the battery and corrodes the wire.
Hope this helps.

Kind Regards, Craig Dyer

Moerig

This effect, commonly called "black death" in the ol'days is about as old as ni-cad technology itself. Have not seen it much in recent years but with the decline and illegal status in some countries the use of Ni-Cads, quality is probably slipping. JR probably relies on a supplier that has deminished it QC. Anyway they should have stopped NI-Cad sales years ago. Its a real burden on the environment and should NOT be disposed of in regular trash.
IN SEVERE cases it could spread to your PCB in the TX. Check that too, as a matter of urgency. Most comonly it follows the ground wire all the way round the TX.

Moerig

To be clear do you mean it cannot happen to Ni MH at all? I have long forgotten the chemistry behind this phenomenon. It used to be a debating point in R/C circles. Can you elaborate?

Dave Wilshere

David

You been using wall type chargers for the tx?

The 10x Nicad pack is no longer available, so the 12x NiMH is the only choice for existing 10x owners.
I found that 10x packs were only good for around 2 years, even charging with a Graupner Ultraduo plus 30

Dave Wilshere

Gordon Mc

My Feedback: (11)

Although that may be the case for complete packs in the case, don't forget how easy it is to replace the innards of a 10X battery unit.

I monitor & cycle my packs regularly, and when I see them diminishing I just buy a brick from Dave at Radical RC ( http://www.radicalrc.com/shop/ ), pop the heat-shrink and cardboard endcaps off of it, and then stuff it into the old case. I also put a sticker on the case indicating the date and type of battery replacement so that I always know how old these packs are.

Gordon

Bob_B

My Feedback: (11)

David,
A friend had his new 12X battery fail like this too. He sent the entire TX back and they replaced the cell inside the battery case as they did not have replacement packs on hand yet.
Bob

Eddie P

My Feedback: (4)

'Black Death' used to get a lot of attention back in the NiCd EDF days because of the vast numbers of cells in our inventories. I considered three years to be the basic shelf life limit of a critical use NiCd pack before recycling and changing out, as long as I cycled the packs regularly and guarded against under voltage / cell reversal. I have not had a NiCd in my inventory for years but other battery types also have their quirks and shelf life issues too.

Dee Miller

My Feedback: (2)

FWIW my first (I bought 2) 12X battery fried itself and expanded so that it was tough to get out of the radio. It was an NiMh 2000mah.
I requested Horizon replace it with the 1100mah NiCd they had in stock. I have no clue about the cause, but I have never been impressed
with NiMh because they do hold a charge well. Sure enough that is true with my other 12X. Someday a new technology will help us; maybe A123.
The charger that comes with the 12X is not worthy of that class of transmitter.
Dee

David Gladwin

Yes Dave I have always used the supplied wall charger for charging Txs. I do that because the diode on the battery PC board prevents use of an Ultra Duo type charger. This morning I soldered up a charging lead (cut from an old Macgregor charger, RED is NEGATIVE) and replaced the diode with a jumper.Connected it up to my faithful UD Plus 2 . A few moments later part of the PC copper adjacent to the main socket burnt out. It least that was on an old pack not in Tx use ! So, its back to wall chargers for now !!

Any advice on how to charge JR Tx batteries without removing the pack from the Tx using a fast charger would be most welcome !

That said I have been using JR wall chargers on JR Txs for over 25 years, this is the first problem I have experienced !

Regards and thanks, David.

craigdyer

Hi David

I have owned a 3810 and now run an MX22 and have bridged the diode out on both with great success...Maybe take your transmitter to a tv repair centre and get them to bridge it for you. I charge my TX with an ACE smart charger

Kind Regards, Craig Dyer

David Gladwin

Thanks Craig BUT I have already bridged the diode (removed the diode and soldered in a jump lead) Is that what you meant ?

It was the copper land on the PC board that burnt out AFTER I soldered in the jumper.
Regards, David.

Dave Wilshere

David

The wall charger will always over charge packs. Never never use wall chargers-I call them guess charging.

The new Graupner chargers, like the Ultraduo Plus 30, Ultramat 16 etc all charge JR tx's without any silly diode jumping.

I use a Graupner JR tx charge lead and alway set the charger to manual (not Auto) max charge current of 0.8A (800mA)-I generally charge my 10x at 0.6A through the battery charge socket.

I charge my DX-7, MX-22, DSX-9, four PCM 10x's and an old 3810ADT all this way

Dave Wilshere

Dee Miller

My Feedback: (2)

I am using an Orbit Pocket Lader in the field and an Alpha 4 at home to charge batteries while in the transmitter. I purchased a plug from an electronic
supply house and soldered the negative to the center and the positive to the outside. I did not touch the diode and it works fine and has for years with the
10X and now the 12X. The chargers can be set to your choice of amps. The Pocket Lader stops when the battery is full; the Alpha 4 goes to trickle when full.
Dee

rolsen12

Here is a good way to protect yourself against battery pack problems of any kind.
I put new packs in every two years.
I don't test them or cycle them, or any thing but throw them away.
Think about it, they are very cheap insurance every (2) two years( 24 mounths).
I don't trust any battery longer than that, and I have never had a battery failure.
I have done that for 50 years.

Gordon Mc

My Feedback: (11)

I had a brand new RX battery pack fail about 3 minutes into the first flight I used it for, in my helicopter (which started chasing me around !).

Just because something is new, doesn't mean it is good – so now all my new batteries get tested & cycled before use in a model. I should have done that from the beginning, but I was dumb and was ignoring the expertise I'd gained in the electronics testing world about how a burn-in period significantly reduces the liklihood of a failure during critical use.

Gordon

David Gladwin

Thanks guys, but it just will not work for me on any JR radio (PCM10, PCM 10X, PCM 12X, Apex computer) but my Pocket lader WILL charge my DX 7 so I know that leads and polarity etc are correct. I guess the diode is preventing a voltage feedback to the charger and hence it "sees" no battery.

Any suggestions ?

Regards, David.

PS Just tried ANOTHER 10X pack. Pocket Lader set to .5 amp , no reaction from charger. Replaced the diode with a jumper, set charge to .5 amps, works fine !!

So the question is why don't you guys not have to replace the diode with a jumper. Frankly I would MUCH rather use a proper delta peak charger than the supplied wall charger. I pressume the diode is only to prevent dicharge from the charge socket but has no other affect on the transmitter circuitry. Any comment anyone ?

PPS. I have now modded both of my new 12X NimH batteries by removing the diode and inserting a jumper. (its the same PC board as the 10X battery) Works FINE charging at 1 amp (the 12X battery is 2200MAh) and I can still charge with the wll charger if neccessary. I have no idea why one of the copper land burned out on my first try, apart from the burnt land everything else looks fine !

CiprianGugu

My Feedback: (17)

That was the first thing that I do with a new transmitter: jump the diode if it has one. The wall wart charger is not even used after the initial break in of the battery. Never had a problem.

Harley Condra

My Feedback: (4)

No BS Batteries has reloads for the JR cassette battery packs.
They are available in 2100, 2500 and 2700 Ma capacities, (NiMh) and Steve will do the labor for you with a one day turn around if you don't want to make the swap yourself.
The 2700 is a very tight fit in the cassette.
The price is $47.95 each.
www.hangtimes.com/txpacks.html

Read the cautionary statement on the site regarding these high capacity cells.

Hawkflyer

Hi David,
I have a JR3810 I can just plug my Swallow AC/DC charger straight in and charge as I like. I cant discharge or cycle the battery as the diode in the transmitter prevents this but I can easily just remove battery pack from TX to do it. I have replaced Tx batteries recently with Enloop (sanyo) 2000mah NIMH. They are suppose to be a newer technology NIMH and they dont self discharge between use. They seem to work very well.

Cheers Hawkflyer

David Gladwin

We crossed but all is now well, no diodes ! Anyway the chargers supplied with my 12Xs (by Model Flight in Australia) has a very low output so good riddance to them !

The NiMh immediately off charge is showing 11.8 v. whereas before the highest I have seen is 11.4 V, however, it rapidly dropped to 11.4 on Tx switch on.

Regards, (and many thanks)

David.

David Gladwin

Yep I tried my Swallow charger on an old PCM 10 WITH diode, it works, the Ultra Duo and Orbit chargers dont ! !
many thanks, David.

David Gladwin

http://www.rcbatteryclinic.com

Well worth reading for us all.
Regards, DG.

Moerig

Good link with real good info.
have you noticed that your cellphone and other well designed electronics, especially Li-Ion equiped, do not have real chargers but power supplies. The device itself manages the charging process since the device knows best what to do with its power supply. It keeps track of usage, temperature, input voltage etc. So why does a "high end" RC system come with a wall wart?
Poor design IMHO