Sherman Charger Issue ?

[DjPanJan]

On 1/9/2021 at 5:23 PM, Adel said:

I notice that the charger makes periodic clicking noise, also accompanied by corresponding LED flicker as you can see from the clip below. I also noticed the same behavior from a replacement charger. If you have a Sherman, does your charger behave the same way, is this normal or sign of a problem with the charger or the wheel ?

 

My brand new charger what come with my sherman do same behavior. Sherman  is created/assembled/packed 28/1/2021 motor date is 13/1/2021. Scary eucworld report 100,7/8 V after green led and charger autoshudown. 

Things i try/test: Plug standard gotway msp 100,8V 3A charger turn to green instant.

Plug smart (switchable) charger display show 101V and does nothing. https://www.1radwerkstatt.de/epages/80603321.sf/en_GB/?ObjectPath=/Shops/80603321/Products/Charger_adj

Plug chargeman into sherman and chargeman not ON(stay off state). On gotway chargeman always show voltage when conect to conectors(propably sherman have diferent behavior). https://eunicycles.eu/en/home/200-chargeman-gotway-100v.html 

 

 

[evil696]

This clicking sound is caused by motherboard, i do my own charger for veteran and it have no clicking sound BUT power on charger drops same as clicking sound on original chrger.

[GoldenOne]

Just got my new sherman, doing the same thing, can any other veteran owners comment if this is normal? 

https://streamable.com/9f5mga

[DjPanJan]

2 hours ago, GoldenOne said:

Just got my new sherman, doing the same thing, can any other veteran owners comment if this is normal? 

https://streamable.com/9f5mga

This is normal is ballancing stage. 

[visionarek]

You’re all forgetting all meters have uncertainty. Cheap multimeters up to 0.5 percent. 101.3 could be 100.8

[Boogieman]

On 3/22/2023 at 1:45 PM, visionarek said:

You’re all forgetting all meters have uncertainty. Cheap multimeters up to 0.5 percent. 101.3 could be 100.8

+/- 0.5% is not that bad in 400V DC range, cheap ones can certainly be worse  Fluke 88V has ±(0.4 % + 2) and thats not their cheapest meter.

My Velleman DVM345DI has 0.1V resolution (400V DC range) and +/-0.5% +/- 3 digits. The digits part made me confused. I guess at 100.X volts it means

+/-0.5 V (0.5%) +/- 0.3V (3 digits at the lowest 100mV part) so worst case +/- 0.8V.

my sherman was adjusted -0.5V from display.

After that both charger display, volt meter and Sherman display showed allmost the same value (volt meter on power supply shows +0.1V vs Sherman and volt meter)

so during charge cycle it showed:

charger 93

volt meter 92.9

sherman 92.9

One ODD thing though. Volt meter showed short spikes where voltage went to 93.7V as if the charging stopped shortly (as if Sherman battery load cut off by main board shortly), really strange. Not sure if thats because i chose to charge at 2A (can chose up to 8A) but really strange?

any ideas ?

 

edit: tested 6A and 8A and both show same spiking.

Also at 6A and 8A the charger voltage deviates from sherman and volt meter (about 0.4V), im guessing due voltage drop in cables to wheel as power increases.

Edited May 27, 2023 by Boogieman

[Chriull]

1 hour ago, Boogieman said:

Volt meter showed short spikes where voltage went to 93.7V as if the charging stopped shortly (as if Sherman battery load cut off by main board shortly), really strange

Seems that the sherman cuts off charging in-between for whatever reasons. I remember reports that sophisticated li ion chargers which stop once charging current drops below some threshold do not work with sherman veteran wheels.

[Boogieman]

On 5/28/2023 at 12:16 AM, Chriull said:

Seems that the sherman cuts off charging in-between for whatever reasons. I remember reports that sophisticated li ion chargers which stop once charging current drops below some threshold do not work with sherman veteran wheels.

Ok. This charger is pretty standard. Jia rui b900-100 so similar to the standard except voltage display and can set 80/90/100% charge (80% does not work though as it stops at 90% there as well) and can chose amps 2 6 8 A.

When charging was done at 2A display is still on but voltage and amps drops very low, i guess its some leakage from wheel.

After 4 or so hours at that low reading when disconnecting and measure voltage its at 100.5V so its seems to charge well.

Im just worried that those spikes happen also when close to full, so that it goes to 102V or something like that.

Spikes are so short that only multimeter register them. Voltage display on charger stays at same voltage, probably just lower update rate on that one.

Edited May 29, 2023 by Boogieman