Tuning the voltage up to increse charging speed is an issue?

[nico87]

I have opened my monster v3 100v charger but it seems the current controller pot is missing

https://ibb.co/Ht6pLM3

The pot in front of the fan is the voltage controller, the other one i assume is the cutoff current controller.

Can the voltage be raised to increase charging speed?

 

 

[Tawpie]

No. Doing so runs the risk of a battery fire.

[nico87]

nevermind, it can't be tuned that much, only goes up to 102v.

Edited May 14, 2022 by nico87

[Wolverine]

The voltage of the charger has to be high enough to push a useful level of current through the battery's internal resistance. In practice that means a few volts higher than the battery normal output voltage. Let’s take an example: a 12V car battery charger must put at least 14 volts or thereabouts across the battery. If the charging voltage is too high, the excess energy not going into the chemical storage would end up as heat. But there’s more than that, greater current and higher voltages charge batteries faster, but there's also a limit to what they can take, which must always be taken into account.

[alcatraz]

Increasing it would only increase charging speed after 80-90% charge.

Get a high amp charger.

[OneLeg]

leave the voltage as is, if anything lower it to 98V per cell... get a charger where you can adjust the amps manually...

The lower the voltage the better, the slower you charge the better for life battery.....

[Chriull]

On 5/14/2022 at 2:33 PM, nico87 said:

Can the voltage be raised to increase charging speed?

That would be against the principles of li ion charging.

Li ion charging consists of a constant current and a constant voltage stage.

The constant current stage can be accelerated by increasing the current until the connectors, wires and cells limits.

Constant voltage stage is best conforming to the top balancing bms, which are mostly set to 4.2V per cell.

Increasing max voltage to something higher is just stressing or even endangering the cells.

As @Tawpie and @alcatraz already wrote above.

[mrelwood]

On 5/14/2022 at 8:56 PM, nico87 said:

nevermind, it can't be tuned that much, only goes up to 102v.

Even at 102V the charger would disturb the cells’ balancing process, and rely on the BMS’s emergency charging cutoff to stop the charging process. The battery life would be shortened for several reasons. And the charging time wouldn’t even be shortened by any amount worth mentioning. Please adjust it back to 100.8V and get a faster charger if you need one!

[OneLeg]

The life shortening of  charging at 4.25V is well documented in some papers I saw... 102V = 4.25V

[nico87]

17 hours ago, Chriull said:

That would be against the principles of li ion charging.

Li ion charging consists of a constant current and a constant voltage stage.

The constant current stage can be accelerated by increasing the current until the connectors, wires and cells limits.

Constant voltage stage is best conforming to the top balancing bms, which are mostly set to 4.2V per cell.

Increasing max voltage to something higher is just stressing or even endangering the cells.

As @Tawpie and @alcatraz already wrote above.

Yes, i was just wondering, don't really know how the li ion charging works.

15 hours ago, mrelwood said:

Even at 102V the charger would disturb the cells’ balancing process, and rely on the BMS’s emergency charging cutoff to stop the charging process. The battery life would be shortened for several reasons. And the charging time wouldn’t even be shortened by any amount worth mentioning. Please adjust it back to 100.8V and get a faster charger if you need one!

Tuned it back to 100.8v, doesnt seem to be useful raising it to a higher voltage

 

Reading the watt meter from the wall, this charger is drawing 5.3 amps and 680watts, this things have a very bad efficency, do they? The specs are 100v3amps, and it needs almost double the amount

Edited May 17, 2022 by nico87

[RagingGrandpa]

On 5/14/2022 at 8:33 AM, nico87 said:

The pot in front of the fan is the voltage controller, the other one i assume is the cutoff current controller.

 

The usual YZpower design: it's multiple small supplies in parallel (here, a YZ210 + a YZ150).

The trim pot is only the CV threshold for each supply. They should be set to the same voltage; otherwise the lower one will stop contributing current 'too early,' which is safe but means reduced charging speed. We want both of the supplies to CV exactly at 100.8, and not give up early.

If you've got them out of balance, I think you can do a quick and dirty adjustment by turning them both down below 100V, then raise only one to 100.8V, then raise the second until you see 100.9V, then reduce just a tiny amount back to 100.8.

There is no trim pot for the current threshold.

And there is no end-current shutoff. The light will turn green, but the power supplies are still active and delivering a trickle current  
So unplug the charger within a few hours of turning green, and don't leave it connected for days.
 

8 hours ago, nico87 said:

 Location: Florence
this charger is drawing 5.3 amps and 680watts, this things have a very bad efficency

Where did you find 125V_rms mains power in Italy?  
And seems a bit strange for your watt meter to display apparent power in units of Watts... because VA is more correct (V_rms * A_rms).

The loss is the power factor (60% typ), not heat... and lucky for you, your utility bills you for real power, so this power factor doesn't cost you money. RMS current is 5.3A, but real power is more like 320W.
So the only remaining annoyance is your circuit breaker- which only knows current, and will trip sooner with a poor power factor  

Real power, RMS mains current, and pf example shown: 
(apparent power would be 49VA, despite real power being only 24W)

Edited May 17, 2022 by RagingGrandpa

[techyiam]

1 hour ago, RagingGrandpa said:

And there is no end-current shutoff. The light will turn green, but the power supplies are still active and delivering a trickle current

Just to confirm. This will go on unless one cell reaches 4.25 V. Then the charger will shut down power to the whole battery pack, right?

Thanks.

[RagingGrandpa]

47 minutes ago, techyiam said:

This will go on unless one cell reaches 4.25 V. Then the charger will shut down power to the whole battery pack, right?

Almost.
After any cell reaches 4.25V, the EUC will shut down the charging input.
The charger will keep trying, but because the EUC interrupted it, no current flows. 
And if the pack is healthy and balanced, this shutoff won't occur, because 4.20 * 24 = 100.8V, the charger's maximum output voltage. No cell will reach 4.25.

[nico87]

14 hours ago, RagingGrandpa said:

The usual YZpower design: it's multiple small supplies in parallel (here, a YZ210 + a YZ150).

The trim pot is only the CV threshold for each supply. They should be set to the same voltage; otherwise the lower one will stop contributing current 'too early,' which is safe but means reduced charging speed. We want both of the supplies to CV exactly at 100.8, and not give up early.

If you've got them out of balance, I think you can do a quick and dirty adjustment by turning them both down below 100V, then raise only one to 100.8V, then raise the second until you see 100.9V, then reduce just a tiny amount back to 100.8.

There is no trim pot for the current threshold.

And there is no end-current shutoff. The light will turn green, but the power supplies are still active and delivering a trickle current  
So unplug the charger within a few hours of turning green, and don't leave it connected for days.
 

Where did you find 125V_rms mains power in Italy?  
And seems a bit strange for your watt meter to display apparent power in units of Watts... because VA is more correct (V_rms * A_rms).

The loss is the power factor (60% typ), not heat... and lucky for you, your utility bills you for real power, so this power factor doesn't cost you money. RMS current is 5.3A, but real power is more like 320W.
So the only remaining annoyance is your circuit breaker- which only knows current, and will trip sooner with a poor power factor  

Real power, RMS mains current, and pf example shown: 
(apparent power would be 49VA, despite real power being only 24W)

strange readings, the voltage anyway read 220v. When charging from a street charging station it showed a 0.300kwh drawn.

Is the adapter plug (Us to Eu) playing a role?

[M640x]

When I had my Z10 I wired two charger outputs in parallel to double the amps/charging speed.  Caution though, whether it's 2 or 12 chargers, there is a max charging current that the batteries in the pack can handle.  I did my research before the mod.