karolh

For as long as I can remember I have been leaving the batteries for all my Rx 's disconnected in an effort to avoid the dreaded black wire syndrome attacking the negative wires in the circuit. Now that I have gone to gas engines and CD ignitions I have not been disconnecting the ignition battery from the switches etc and so far so good, but I am wondering if I should start doing so. I have been told that with the improvements in the wire quality now used in our radio systems the possibility of the black wire occuring is much less than before, but I would like to get some opinions on this.

Karol

Tired Old Man

My Feedback: (1)

Karol,

I haven't encountered this problem for a long, long time. I don't know if it was a change in materials, a change in fuel, or what, but I haven't come up against the black wire syndrome in at least 10 years now. I never disconnect nicd or nimh batteries but I do disconnect lithium batteries for current drain/switch reasons only.

w8ye

My Feedback: (16)

I think tinned wire holds up better than bare copper

Jezmo

+1 for no problems for at least ten years, maybe more. Same as Pat, I don't disconnect anything except LiPos. For clarity, I only use NiMH's and A123 on the fuel stuff and LiPo on the electric stuff. All of my NiCad stuff is gone.

karolh

Thanks guys as I find your comments quite comforting.

Jez,

I guess I am really just a old fashioned fart, as all my glow and gas models are nicad powered. My main reasons for sticking with them is that they are very forgiving as every now and then something gets left on and when totally depleted they most times only need a few cycles and they are back up to snuff. Plus most of my stuff is 1.20 size at best and so their power requirements are relatively small.

W8ye,

I had to type this posting three times before it got accepted as each time the system ate it [:@]

Karol

w8ye

My Feedback: (16)

I participate in some other sites too and all of them will eat your edits sometimes.

RCU has been bad recently about hanging up. Unless you want to wait an hour, you have to go in and delete your RCU session id cookies to get back on.

Rodney

Black wire is almost always (in my 30 + years of experience 100%) experienced only with NiCad battery use and then only when using wet cell NiCads or Nicads which have had a ruptured seal. It is evidenced as an actual irreversible change in the chemical makeup of the wire where it becomes brittle and unsolder-able. The only cure is complete replacement of the effected piece of wire. I have never seen a case of black wire (corrosion, yes, black wire no) disease when NiMh's were used or where carbon zinc or lead acid batteries were used.

karolh

Never knew that about Nicads or NiMh batteries for that matter, as now knowing this I might have to give switching to NiMh packs a very serious thought. Do both battery types have similar life and charge cycle expectancies ?

Karol

w8ye

My Feedback: (16)

NiMh has a higher internal resistance so they do not have as much instantaneous amperage capacity as the NiCd batteries.

Also the charging voltage drop at peak is less than on a NiCd so some older peak detector chargers will not see the peak.

NiMh also has more faster charge deterioration setting on the shelf than a NiCd.

Other than that - They are about the same.

karolh

Thanks.

Tired Old Man

My Feedback: (1)

With an exception for the Eneloop NiMh, which maintains a stored charge much longer than NiCd.

Jezmo

All of my NiMH packs are hand built using only genuine Sanyo Eneloops. Be aware there are copies being sold of the Eneloops (we can guess where they might be made) and they are not nearly as good as the true Sanyo's. I have a West Mountain Radio CBAIII battery analyzer and using good wire and connectors, I can get them to hold a 10 amp discharge without falling below 1 volt per cell until roughly 50% discharged. They will do 6 amps and not fall below 1.1 volts per cell until nearly 75% discharged. When running dual packs that's 12 amps of current and that should be plenty for most stuff up to and including the 50cc stuff. For a long time (more than a year) I flew my 50cc Extra with two five cell Eneloop packs wired through dual switches into a Spektrum AR7000 receiver without ever having a glitch. The flying as mostly wild 3D stuff. The point of this is 5 HS-7985MG's and one HS-7955TG in the 17.5 lb Extra were all handled quite nicely by the Eneloops.

Yes, I do have to be careful so as not to completely discharge them although I have done it and they recovered but I found my mistake the next day so they didn't sit very long fully discharged. That particular pack is still going strong and it's almost 4 years old with lord knows how many cycles on it now. In case you can't tell I really like the Sanyo Eneloops. LOL Almost as much as I like my A123's.