Zero 8 , Qs-s4 screen flashes... thats all though HELP

[s1dways]

Hey guys I've got a zero 8 I picked up with a smashed lcd for cheap. Figured that was the issue it wasn't working. Brought a new one yet I've had no luck.. Still it's just dead. Battery's showing 46v I'm running a qs s4. which ive already gone through the motions of opening up the back and matching the wiring outputs i believe.. i cant get this thing to seem to work, or even show me a display, the mr100 flashes on for 2 seconds when i plug it in,but still no display, what ever help would be really appreciated thanks


with the controller, i lalso picked up a new mr100












All reactions:
33

 

[amberwolf]

What happened to it that caused the damage? Knowing that could help lead to a solution.

When you read the battery voltage at 46v, is that while it's still connected to the controller and display, after trying to turn the system on? If not, try that, and see what you read on it then. If it drops way down, then the battery's BMS is turning off the output to protect the cells from damage.

It could be doing it if the cells are not all the same voltage, especially if some are very low and the slight load of turning on the controller drops them below LVC.

It could do it if the controller/etc is damaged and excessively loading the battery (like shorted FETs, etc), so the BMS shuts down from overcurrent.





Other thoughts:

Is it the original controller? if not, it may not be compatible with that display. (not usually something that causes the specific problem you're seeing, but if you have other troubles after fixing this, it's something to think about).

Also, there can be different versions of displays with different firmware, and they aren't usually intercompatible with all controllers even if those controllers normally use that style of display.

 

[s1dways]

Thanks for your knowledge, The controller's the original one i believe, but i got this cheap as my friend crashed it, hurt herself and smashed the LCD , So i brought a new S4 to replace it, She said the battery was on its way out, but thought she was just wrong after i got a charger and it charged fine, As for the drop in rate, its around 46v with meter reading direct from the battery prongs but i took a reading from the red positive, it was only like 20ish, and just slowly was rising . Im guessing the battery is buggered after all, like you say it should never drop anywhere near that low, do u think if i had the charger plugged in at the same time the lcd might come to life, im just so over it now. i was about to buy a new controller, after buying a tf100 and then a new s4.. oh plus a charger..
Anyone in NZ needing any of it, or has a cheap battery for me haha

 

[amberwolf]

She said the battery was on its way out, but thought she was just wrong after i got a charger and it charged fine, As for the drop in rate, its around 46v with meter reading direct from the battery prongs but i took a reading from the red positive, it was only like 20ish, and just slowly was rising . Im guessing the battery is buggered after all, like you say it should never drop anywhere near that low,

Do you have anything else that runs on the "48v" of that battery? If so, you could test the battery using that. If not, then if you have an old heating element from a stove, you could connect that to the battery output, and measure the voltage at the terminals while it's connected. If it stays at the 46v, it's probably not the battery. If it drops radically in voltage, it's the battery.

But, a fully charged 48v battery should be about 54v or a bit more. 46v is closer to empty than full. So, if you've left it on the charger till the charger stops, then there *is* something wrong with the battery. (assuming the charger outputs it's full 54.somethng volts as marked on the label, when not connected to the battery)

do u think if i had the charger plugged in at the same time the lcd might come to life,

depends on whether it's a common-port BMS or not; if it is, then the charger is wired to the same place as the controller connector inside the battery, so the charger voltage would pass to the controller, and power it on.

But...if it's not the battery causing the problem, and it's a short in the system, it could damage your charger, too.

 

[s1dways]

But, a fully charged 48v battery should be about 54v or a bit more. 46v is closer to empty than full. So, if you've left it on the charger till the charger stops, then there *is* something wrong with the battery. (assuming the charger outputs it's full 54.somethng volts as marked on the label, when not connected to the battery)

Hmm ok ill charge it again now, even though i only charged it about a week ago and its only been plugged in for testing, currently its reading 46.7 i dont think ive ever seen it above 50 though and yea its a 54v charger - ill see how long this takes, cause its bearly been used so shouldnt take long i would think

 

[s1dways]

depends on whether it's a common-port BMS or not; if it is, then the charger is wired to the same place as the controller connector inside the battery, so the charger voltage would pass to the controller, and power it on.

But...if it's not the battery causing the problem, and it's a short in the system, it could damage your charger, too.

Meh if it stuffs the charger then its worth the risk, ive only got this 48v one as abit of a project , hopefully ill get another 10x soon, there far more fun

 

[s1dways]

Ok hour on charge, light went green, only 47.5v thats not good

 

[s1dways]

Ok hour on charge, light went green, only 47.5v thats not good
after attaching the charger too it finally came to life

 

[amberwolf]

Sounds like a bad battery. One or more cells failed in one way or another.

 

[s1dways]

Yep im of the same conclusion, So after afew YouTube videos i opened the pack up, Funnily enough from the battery connecter or the charging port its reading 47.2 as shown in the pic, freshly charged, But from the main positive inside the cells to a negative its reading 53.0..... So would that be a issue with the BMS or how do i isolate the bad cells and attempt to replace them