Grin Satiator not charging 52V Li-ion battery

[mcbutler]

Hello all,
I have a brand new 52V 20A downtube battery using the ST3 connection. Grin satiator model 4808 with grin supplied XLR - ST3 cable.
Battery charges fine on supplied charger, grin charges my 48V battery no problem.
ST3 has charging voltage at the plug when a force start is initiated
Grin will not charge the battery when connected even when initiating force start!
Grin firmware is 1.039
Wondering if different cables have different drivers maybe?
Any ideas ?

 

[BVH]

I experienced something similar. I have three Satiators and use two at the same time to charge both batts on my bike. The newest charger would give the same symptoms you have. I determined that the Satiator cable was malfunctioning by replacing it with the cable from my third unused unit. Have not had the problem since. This was about 2 years ago.

 

[mcbutler]

Thank you for replying, I appreciate you taking the time.
Just to clarify, did you swap the main cable that screws into the satiator or the adapter cable that connects the main cable to the battery?

Thanks again,

Mark

 

[BVH]

Both pieces. IIRC, I may have wiggled the screw connection at the Satiator and seen indications of a make & break event. Not 100% sure but I think I did.

 

[amberwolf]

Do you have a voltmeter? You can force start the satiator, then measure hte voltage between the charging pins + and - without it connected to the battery. You should see the same voltage there as on the screen, if the cable is ok. Otherwise there is a connection failure somewhere between the point you're measuring and the inside of the Satiator.

 

[mcbutler]

Hi Amber wolf, Thanks for the advice, I have just done as you suggest and the readings at the end of the satiator lead match exactly the reading on the satiator display.
I have read that if I have zero V on the battery side of the charging port (like I do) then the charger cannot see the battery, apparently this is usually a dodgy BMS.

 

[mcbutler]

Here is something interesting, look at these three photos.
The battery port and OE charger seem to have a slightly different profile on the centre (signal) pin than the satiatior lead.
The satiator lead is actually harder to push in and remove than the OE!
I am wondering if different versions of the ST3 connector exist?

 

[amberwolf]

Here is something interesting, look at these three photos.
The battery port and OE charger seem to have a slightly different profile on the centre (signal) pin than the satiatior lead.
The satiator lead is actually harder to push in and remove than the OE!
I am wondering if different versions of the ST3 connector exist?

It might mean the electrical connection is not being correctly made, if for instance the pins and barrels don't match diameters, it could either not connect at all (pin floating inside barrel) or have higher resistance than it should (and it would drop voltage across that resistance during current flow).

 

[mcbutler]

After having ordered ST3 connectors from 2 companies only to find them all slightly different I decided to cut the lead on the original charger, install an XLR plug to rejoin it.
This way I can unplug the original plug from the OE charger and attach it to the satiator.
So - Job done, OE charger tested and it charges the battery perfectly.
OE plug detatched from OE charger and plugged into satiator
Satiator force start initiated and polarith and op from the plug checked - all ok
Satiator plugged into battery, nothing happens.
Force start initiated - voltage rises to around 45.9V then slowly trails to zero over a few seconds then 'connect battery' message.
Also seeing a 3.3V line on the display!!

Video here

Any ideas guys

 

[amberwolf]

Does the current (A) on the screen ever rise from zero?

If you actually see the screen's voltages on the plug (or beyond it, in any of the cable connections) with a voltmeter as it's happening, then the Satiator is probably doing what it is supposed to.

But the charge port of the BMS (C-) could be turned off because something inside the pack has exceeded a limit in the BMS (or the BMS is broken); in this event the Satiator can't pass current into the battery, so it will stop trying to charge because the shutoff current limit in the profile is reached and it thinks the battery is full (or the BMS has turned offf for balancing, protection, etc).

Note taht the test below may not work if the charge and discharge ports are separate at the BMS (most common type) because the intrinsic diode of the port control FETs will allow current *out* of the port even when it's disabled:

On the battery's charge port, if it reads the correct voltage there before connecting the Satiator, what does it read if you connect a load between the charge positive and charge negative? The load can be anything small, like an incandescent light bulb (12v car type or wall voltage type, etc), or a resistor if you have one laying around. The meter should be connected to the pins while the load is connected, so you can see what happens.

If the voltage remains the same as the unloaded voltage and doesn't drop significantly, the charger port is probably "on" and should pass current (see note above, though). If the voltage drops significantly or to zero, then the port is off and the BMS is protecting against charge because it sees a problem with the cells (real or not), or is defective or wired wrong, etc.

If the BMS has separate C- and P- (discharge) ports the test above wont' work correctly, and will seem operational when it may not be. You'd have to open the battery and test voltage at the B- lead (meter black at that point and meter red at B+) while the satiator is in force-start mode as it first ramps up to full voltage, to see if the voltage you see on it is also seen at the B+/B-. If the voltage there never changes even a flicker, and no current shows up on the satiator, then the C- port is probably off.

Then you can test voltages of the cells at the BMS PCB to see if any of them reads incorrectly at that point to figure out why the BMS has shut off the port.