sschwell

I have a Triton charger purchased approximately 6 months ago. I’m having a problem with the cutoff voltage when discharging NiCd packs in the Dchg/chg and Chg/Dchg modes (cycling modes). While the manual states that the cutoff voltage is preset to .8v/cell, my charger continues to discharge well below the expected 3.20V for a 4 cell pack. This morning I noticed that it was still discharging a 4 cell pack even though the output voltage was displaying 3.01 V. I immediately terminated the discharge. To check it I scrolled to the individual discharge function, set the cutoff voltage to .8vx4 ( 3.2 v) and started the discharge. The Triton sensed the output voltage to be below .8v/cell and almost immediately terminated the discharge.

Why is the charger not terminating the discharge at the proper voltage when in the cycling modes? Has anyone else experienced this problem?

90sparty

I just got a new Triton and noticed the same thing (see an earlier post on discharge cutoff voltage). As you indicated, this occured, when I was using the D>C on my 4.8v Nicd. It would not cut off at 3.2 volts. If I did a regular discharge function, it would cut off at the appropiate voltage (I had it programed to 1.1 v / cell). So I experimented around a little bit and the next time just kept letting the battery discharge since it was a battery I did not care much about. The charger did cutoff and went into the delay mode when the voltage finally reached like 2.7v (or maybe 2.4 v I forgot). I called Hobby Services and they did not provide a whole lot of information. My only wild guess at this point is the cause may be due to my 12'ish voltage source I am using. I am using my boat battery that I am storing in the basement over the winter. I checked it with a voltmeter though as well as the data screen on the Triton and is was reading 12.5 volts.

Let me know if you find out anything.

guver

My Feedback: (325)

When doing a cycle function could the triton be detecting the number of cells wrong? I am hearing more and more about this problem and will check mine to see.

sschwell

Thanks for your comments. I have an email in to Great Planes Support on this. I'm hoping to hear back soon. Meanwhile, I hope to hear from more people on this topic, particularly Triton owners so we can determine if this is a firmware problem with the product. If so I'm concerned that people may be inadvertantly over-discharging and consequently reversing cells.

guver

My Feedback: (325)

I just been playing with 3 differeent tritons and various cell counts.
The discharge function works ok, but the discharge to charge function doesn't work well.

It seems to have something to do with
1- auto detection of cell count
2- display updates not exactly the same as what's being seen by the charger. In otherwords you have to really stare at it and see that the voltage sometimes drops fast enough that you are not seeing the true voltage. It varies greatly with the rate of discharge and the state of charge of the batt.

I will do some more and try to figure out why it will sometimes discharge below the .8 value.

90sparty

I tried again tonight using the D>C function on my 4.8v ni-cd pack and watched the screen closely as well as had a Fluke on it. The discharge stopped at 2.70 v and went into delay. I then aborted the function again and immediately again started the D>C discharge. Again, the discharge stopped at 2.70 v.

Ross Kean

Is the 2.70V, by any chance, the loaded voltage? I was wondering if the Triton was displaying the loaded voltage during the discharge but was deciding when to stop on the basis of the unloaded volts. It seems to me that it stops drawing current (or adding current during charge) to measure at periodic intervals to see where it is. Just a thought. Maybe you should measure the voltage with your Fluke after the completion of the discharge cycle.

Ross

guver

My Feedback: (325)

I believe it has something to do with the speed or rate at which the voltage is dropping, but as far as I can tell during discharge it does not stop (like during charge)

sschwell

Hey guys I greatly appreciate all the attention you are giving this problem. If only GP would take the issue as seriously. Here are two responses from GP support publised verbatim. I am posting the emails in full. Note that I initially contacted GP product support as well as GP electronic support. That's why I got two responses. The email I sent them was exactly as the first post in this thread. Note also that both responses from GP are from the same chap and neither really address the problem. The one regarding sampling every minute may have some relevance if the voltage isn't being sampled under a load. Overall I think GP is in denial about this problem - "this is nothing to be concerned about". I hope this thread will alert more people that the cycling modes may be ruining battery packs (based on the testing being reported here).


Thank you for your recent e-mail. The Triton checks voltage approximately once every minute during discharge. If the predetermined cutoff voltage falls between this sampling, it will discharge lower until the next voltage check occurs. This is nothing to be concerned about.

Hope this answers your questions

Sincerely,
Craig
Product Support

Thank you for your recent e-mail. In cycle mode, the discharge voltage is fixed at 0.8V/cell and is not adjustable by the user.

Thanks for writing!

Sincerely,
Craig
Product Support

guver

My Feedback: (325)

It seems at a very slow discharge rate the voltage will not be dropping too fast. However on a much higher rate the battery can vary in voltage a lot during a 1 minute increment or interval.

Trogdor the Burninator

I've been using the Triton for a year now to charge cycle etc packs and find the first GP response pretty much what I see and have no problems with it. I think the sampling is done more often than every minute and since there's no way for the triton to determine the cell count, it must just be some algorithm that calculates load vs. voltage drop. It's obviously not set to 0.8V per cell since there's no way to really tell but it just shuts off at that quick dip in the voltage that occurs when discharge is complete on any size pack. I find no reason to worry about this at all. All my packs that I've been using with the Triton function completely normally. Also the time that is spent below 0.8V is SO short it can't matter as the voltage will recover quickly after taking the load off.

guver

My Feedback: (325)

I would agree, not to worry at all. In fact I don't worry about cycling either . dischargeing either.