T&L Publications

I got one of these units, and it seems pretty good for testing and rating li-ion batteries.
but i am wondering if anyone has ever used one, i'd like to know if there is a way for the back light to stay on without hacking the unit ?
i'm sure i could find out, but if there is a setting, that would be great, but it does not say in the manual anywhere.
i have looked inside of it, and there is just a transistor controlling the leds. i could bypass the collector and emitter with a switch if need be.
if you press any of the buttons, the leds come on, but your current view of the page changes as well, and you have to press it a few more times to get back to the page you was on. and after 3 seconds or so, it's out again.

I found it in this manual

https://images-na.ssl-images-amazon.com ... cbvBaL.pdf

DISPLAY Selection
LCD Display Backlight Control. Press and hold the DISPLAY
button for more than 5 seconds to toggle the backlight mode.
To turn on the LCD Display Backlight press and hold the
DISPLAY button for more than 5 seconds. The backlight will
remain on continuously.
To return the LCD Display Backlight control to auto-off
(backlight turns off after 30 seconds of no button press) press
and hold the DISPLAY button for more than 5 seconds.

There was some stuff on you tube too

i tried this,, did not seem to work,,
mine is the 3400 model with v3.1
I'll try it again..
mine did not show any menu sort of options, it just selects between the different charge / discharge modes.

Hello there,

I have the same model apparently, on the back it says BT-C3400 v3.1 and when i press and hold the DISPLAY button for about 5 seconds or so the display does not turn off anymore like it does before i do that.
You reminded me i had to charge one of my batteries so i just tried this again about 5 minutes ago.
All i can think is that something is wrong with that unit and so maybe it has to be returned and replaced.
Are you sure you hold it in for 5 or more seconds? Maybe you are releasing it too fast.

There's no menu but the other buttons have other effects that show charger current, etc.

hi all.. i tried it again and counted a little slower, and it seems to work now.. but the book says nothing about it, and there is no indication it worked, til you left it alone and waited for it to time out.. i waited bout 30 seconds and then it stayed on..
thanks again .

Hi again,

Oh i am happy you got it to work now.
Yes, you have to wait the 30 seconds to see if the display goes off again, which it does not if you held in the DISPLAY button long enough. THat's the right time too i think, 30 seconds, because if you dont press the button and hold for 5 seconds it turns off after 30 seconds.
I use that function now and then, but not as much as when i first got the charger. Now i just stick a battery in there and maybe set the current, then let it go and check later.
What i dont like is when i do not use that press and hold function and come back an hour later to check the voltage, when i press the DISPLAY button (to get the backlight to come on again for another 30 seconds) the display mode switches away from Voltage and to something else that i dont care to see right then and there, so i have to press the DISPLAY button a few more times to see the Voltage again. Not too bad i guess, but i would prefer to be able to keep the same mode on the first press after much time has passed from the last press.
Seems to charge pretty well though.

the other thing i don't like is when a battery is finished being tested, it says FULL. and if i press the button to see the capacity, it shows for a second or so, then it goes back to FULL.. i have to keep pressing it to get back to the capacity page.. annoying at times..

Hi,

Oh yeah, i had that problem too. A little strange. Also sometimes i like to review the capacity and the final voltage so that becomes a problem too as you cant just set it and look at the reading because it "goes away" after a short time. Lucky pressing more times will get it back again.

right,, and that's what mine is doing..
it needs to stay put and they could add in another page, so that you can see if it is FULL or still being analyzed.

i am guessing that there is no one here in the states to talk to about it, or a version update.

Hi,

Yeah a new version would be nice. Maybe they have a way to update it but not sure right now.
Then again, i might not want to try it since it is working right now and if the update fails i could end up with a box that does nothing