turboxrayt1fk05

iTrader: (27)

i think novak should do a recall on this sense it looks like more people are having similar issues with the tray (SE) edition , it sounds to me that issue is with the micro processor in the unit getting hot and locking up and not monitoring the voltage being drawn from the battery, just my 2cents, i tried putting a fan behind the tray as is discharging to keep it cool.

Ashley Cobb

iTrader: (28)

CCristo

iTrader: (56)

I have the same issue with both of my SE trays. The far left cell always takes considerably longer to discharge than the rest of the cells. At first I thought it was just my packs, but it does it on my 6 old packs and 4 new ones.

turboxrayt1fk05

iTrader: (27)

i wounder if novak is actually checking on this issue looks like more people are coming forward with this issue , i know novak has a awesome customer service and tech support , i spoke with one of the techs at novak and they dont have knowledge of this happening or if they do , they trying to just patch it up by just telling you to check incoming voltage into the unit.

howard1

Another problem which I have found on the SE tray is the voltage hold. When you select a certain cut off voltage and the system reflects that it is holding at e.g. 1v. However, when you put a multimeter across any cell or the whole pack the voltage is far from constant It jumps from .9v to 1.18v continuously. This is not what is advertised.

Scottrik

iTrader: (261)

That is the difference between "load" and "no-load" voltage. A healthy cell will ALWAYS return to somewhere near 1.2V when load is taken off. It then drops rapidly (and ever more so the more times the button is pushed) to the cut-off "load" voltage when you discharge again. ANY discharge tray with a cut-off voltage does this, not just the Novak one.

howard1

I underdstand the concept of "load, no-load", but the whole point of the tray is to hold the selected voltage. To quote from the Novak site, "the Smart Tray SE will constantly monitor and hold each cell at the selected voltage". The word "hold" is the keyword here, and the tray is not doing this. In essence the system should maintain a specific load on the cells to hold it at the selected voltage. This is not happening!!!!!

Ashley Cobb

iTrader: (28)

in order to keep the voltage level constant it would need to turn the resistance on and off.

Scottrik

iTrader: (261)

You are arguing a narrow semantic point.

ANY continued load will continue to discharge the cell...most definitely NOT the point of a voltage cut-off discharger. It has, effectively, "held" the cut-off "load" voltage as evidenced by the fact the lights only show briefly when you press the button again. Any time the load is released, AND IT HAS TO BE RELEASED OR YOUR CELL WILL GO TO ZERO, the cell will return to "no-load" voltage. There is no escaping that particular fact.

Now I'm not familiar with, specifically, the SE but does it periodically apply load again?

howard1

Scottrik, when the pack/cell has reached the desired cut-off the LED goes out. In my case I set the cut-off at 1v per cell. I hooked up the multimeter fromthe begining of discharge and monitored the voltage drop. At 1v the light went out, but the readings immediately started fluctuating between 1.17v and 0.9v. It never remained constant at the set 1v. Measuring across the whole pack gave the same results viz. fluctuating between 7v and 5v. You say it has held the cut-off voltage, but it has not, because after reaching the preset cut-off it varies. By comparison the LRP discharge tray discharged to 0.6v per cell and maintained it there. This big issue is if they say thats what it does then it must do it!

Scottrik

iTrader: (261)

Whatever.

I'm guessing they're just holding voltage in a different manner. FUNCTIONALLY your voltage is being held at 1v under load. They are doing exactly what they have said they are. Again, yours is a marginal semantic/technical argument at best.

What this new feature does certainly improves upon the original Smart Tray because the when the load ended it ended. Once the battery is at rest it recovers some voltage, hence if you pushed the button again it would discharge for a little while, then subsequently less and less with each push of the button.

turboxrayt1fk05

iTrader: (27)

voltage hold mode is like a voltage limiter that acts when voltage increases slightly and keeps doing that until battery is removed, it would never hold the voltage @ 0.9/cell because voltage on the battery will to increase to a limit without getting incoming power from a source because the heat that was generated inside of the cell and this is what you see on the voltmeter voltage increasing and decreasing, ones the pack temp goes down to room temp more or less you will see voltage no holding as is the pack was hot , Tekin has the battery doctor which monitors battery voltage and it drops to a limit it will charge battery back up without the need of cycling the packs once or twice a month or whatever.

howard1

Problem solved!!!!
I decided to open the Smart Tray and discovered dry joints and areas on the resistor joints with the pc board that had no solder. Re-soldered and tested, and the results were spot on! Cuts off at preset voltage and not such erratic bouncing in voltage. You can now see with the voltmeter when the cut-off ids reached and the circuit switches off and then again on. Thanks for the input guys!

turboxrayt1fk05

iTrader: (27)

can you post some pix of this where you re-soldered and the dry joints?

howard1

turboxrayt1fk05 I have assembled everything already, but when you have undone all the screws and loosened the speaker, slide out the circuit board. When looking at the resistor side of the board, look at where the resistors enter the board. Not all of the resistors had solder on them and those that did had minimal amounts (notmaking proper contact). I applied small amounts of solder in these areas on all the resistors and assembled. Once this was done it worked properly. No jumping discharge volts.