..... Posted July 23, 2021 Share Posted July 23, 2021 Ever since new, my Sherm has always showed 99.2V max. Of course I was a little worried (I tend to do that). Eventually the ota update came and gave me a reason to bother checking the actual voltage. Lo and behold, my charger outputs 100.5 (ewheels and stock), verified while charging with a meter. Whille at 100.5v my wheel reports 99.1V. SO I bumped the screen menu to show actual voltage and it happens to be at the MAX adjusting they gave. I verified battery voltage at the packs while not charging, and the 1.4V adjustment gives me the correct voltage on screen and on the apps. So, how far off is everyone else's wheels? ON a side note, who's adjusting the voltage setting without opening the wheel and getting the actual data? I would suspect that a LOT of people are adjusting this and dont even own an accurate meter or have properly tested for it. If you dont get an accurate test and make adjustments, you are kind of wasting your time arent you? Calibrating things without knowing WHAT the specs really are, is simply trading one inaccuracy for another imho. 2 Quote Link to comment Share on other sites More sharing options...
DjPanJan Posted July 23, 2021 Share Posted July 23, 2021 Instaled FW 1.0.58 checked my voltage in charging/balancing (used stock MSP gotway 3A charger) on charger was 100.8/9 when i unplug charger sherman report 100.7V Then i no adjust voltage 100,7 or 100,8 no drama for me or i am wrong? My sherm is Fat rim red butons knoby stock tire original FW 1.0.56. Quote Link to comment Share on other sites More sharing options...
..... Posted July 23, 2021 Author Share Posted July 23, 2021 (edited) 51 minutes ago, DjPanJan said: Instaled FW 1.0.58 checked my voltage in charging/balancing (used stock MSP gotway 3A charger) on charger was 100.8/9 when i unplug charger sherman report 100.7V Then i no adjust voltage 100,7 or 100,8 no drama for me or i am wrong? My sherm is Fat rim red butons knoby stock tire original FW 1.0.56. Absolutely no way of knowing without testing the packs or the charger output. It's possible your charger is honestly supplying 100.8, but how could you know? My charger says 101v while its pushing 99.4V. Its a waste of time to make any adjustments without knowing if ANY of the equipment correct. Its like adding air to a nascar car tire because your cheap tire gauge says its off. More than likely most wheels are fine. I dont really know wtf Veteran was thinking when they made this adjustment so easy. I cant imagine how many people adjust it and have no clue whats the correct reading. I'll tell you this much. The new pa adjust caught me off guard. I had to verify with a level. It seems that the old pa2 is now more like pa7. Edited July 23, 2021 by ShanesPlanet 2 Quote Link to comment Share on other sites More sharing options...
Popular Post Chriull Posted July 23, 2021 Popular Post Share Posted July 23, 2021 8 hours ago, ShanesPlanet said: If you dont get an accurate test and make adjustments, you are kind of wasting your time arent you? Calibrating things without knowing WHAT the specs really are, is simply trading one inaccuracy for another imho. Or one "calibrates away" a misbalanced battery. The more it degrades, the more often calibration is needed to reach 100% and keep the battery reported as healthy Could be nicely misused by sellers to hide bad batteries. Either private or commercial. There is no "valid" reason anymore for aliexpress to force their sellers to replace a battery if it can be made to show 100%! Such a calibration should only be a manufacturer setting, ?as inmotion does?. Putting it in the hands of everyone should increase ones awareness for sellers reputation! 1.4V is MAX adjustment? If so this at least seems to be "reasonable" - about common range of known inaccuracies and not "too much" degradation that can be hidden... But still this is an adjustment to be made by the manufacturer - during quality control! 4 Quote Link to comment Share on other sites More sharing options...
..... Posted July 23, 2021 Author Share Posted July 23, 2021 (edited) 3 minutes ago, Chriull said: Or one "calibrates away" a misbalanced battery. The more it degrades, the more often calibration is needed to reach 100% and keep the battery reported as healthy Could be nicely misused by sellers to hide bad batteries. Either private or commercial. There is no "valid" reason anymore for aliexpress to force their sellers to replace a battery if it can be made to show 100%! Such a calibration should only be a manufacturer setting, ?as inmotion does?. Putting it in the hands of everyone should increase ones awareness for sellers reputation! 1.4V is MAX adjustment? If so this at least seems to be "reasonable" - about common range of known inaccuracies and not "too much" degradation that can be hidden... But still this is an adjustment to be made by the manufacturer - during quality control! Yup. I think its 1.5v, but your point is valid. I think someone mentioned THEIR mileage went back to zero as well. As a tech, I do enjoy this kind of adjustments. However, I also realize that it can be abused or simply adjusted wrong. LUckily Im pretty sure the bms doesnt care wtf YOU think the voltage is. I'd bet moeny it has its own method or sensor and its much more accurate. Every euc company could avoid so many problems with simple quality control. A little burn in procedure and a set assembly process. But alas, this is the thing of myths and fairy tales....for now. Edited July 23, 2021 by ShanesPlanet 1 Quote Link to comment Share on other sites More sharing options...
Chriull Posted July 23, 2021 Share Posted July 23, 2021 2 minutes ago, ShanesPlanet said: LUckily Im pretty sure the bms doesnt care wtf YOU think the voltage is. I'd bet moeny it has its own method or sensor and its much more accurate. Yes. The BMS does not care about the overall voltage. BMS normally state some +/- (?or sometimes just -) 0.05V for their around 4.2V thresholds. So with this 1 or 2% that's about the same accuracy... Afair veteran has not the "single comparator per cell" circuitry but uses ICs for this? So they could easily have better/different specs. 2 Quote Link to comment Share on other sites More sharing options...
Retrovertigo Posted July 23, 2021 Share Posted July 23, 2021 3 hours ago, ShanesPlanet said: I'll tell you this much. The new pa adjust caught me off guard. I had to verify with a level. It seems that the old pa2 is now more like pa7. That's about right. I think it was Marty Backes video that mentions each step is now 0.3 degrees. I had mine on pa2 so am now flicking between pa6 and pa7 to see which one I prefer. 1 Quote Link to comment Share on other sites More sharing options...
catchi Posted December 2, 2021 Share Posted December 2, 2021 Got a used sherman with a new board (fried after only 500 miles of riding previous owner bought from martys tour and sold it to me after) at 0 adjustments my charger turns off at 98.5 v after reporting 99~ charge it discharges to that 98.5~, Could this issue be fixed by playing with the adjustment and continuing to try charging my batteries? 1 Quote Link to comment Share on other sites More sharing options...
Planemo Posted December 2, 2021 Share Posted December 2, 2021 (edited) 45 minutes ago, catchi said: Got a used sherman with a new board (fried after only 500 miles of riding previous owner bought from martys tour and sold it to me after) at 0 adjustments my charger turns off at 98.5 v after reporting 99~ charge it discharges to that 98.5~, Could this issue be fixed by playing with the adjustment and continuing to try charging my batteries? It comes down to how much it bugs you. Has the wheel already had the firmware upgrade? (maybe Marty done it?) The wheel will be charging to full, despite the 'low' reading. If it bugs you, the later firmware will allow you to adjust it to show 100.8 at full charge. I did this to my sherman after uploading the new firmware. Edit: but as said previously, you really do need to be pulling the panels and checking the pack voltages with a meter just be sure what the voltage is - I think they will be OK but... Edited December 2, 2021 by Planemo 2 Quote Link to comment Share on other sites More sharing options...
Chriull Posted December 2, 2021 Share Posted December 2, 2021 4 hours ago, catchi said: my charger turns off at 98.5 v The "perfect" way would be to first 3 hours ago, Planemo said: checking the pack voltages with a meter and adjust the chargers output voltage accordingly. Second step would be to adjust displayed battery voltage with the (new) firmware to show 100.8V. Normally the biggest problem is to get a calibrated and accurate enough volt meter. To adjust to "about exactly" 100.8V some +/-0.05V accuracy is needed. That means at least +/-0.05% accuracy! Such devices are normally not cheap and need to be regularly calibrated to be reliable. Within the BMS "everthing" happens just with about an accuracy of 4.2V +/- 50mV ~ +/- 1%! As with this same accuracy (+/-1%) maximum charge voltage per cell in manufacturers datasheets is specified. So 98.5V reported at the end of the charge is 1.5% off. The first voltmeter with 4 digits on amazon i found was ~21€ and has an accuracy of +/-(0.8%+2 digits) in the 400V range. Gives an error of +/-1.1V at 100.8V beeing +/-0.083%. So following step 1 and two should with some higher probability enhance your situation. Especially if you have access to some trustworthy better voltmeter. 1 Quote Link to comment Share on other sites More sharing options...
Chriull Posted December 2, 2021 Share Posted December 2, 2021 8 hours ago, catchi said: Could this issue be fixed by playing with the adjustment Btw - the other topic with the additional info you posted seems to get the right answers. This here could maybe lateron be used for fine tuning. 1 Quote Link to comment Share on other sites More sharing options...
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