Going Lithium

[sunshine_eggo]

So I have bulk set to 13.8v on both the Victron 100/30 and IP22 12/30. Should I set the absorb time for as long as possible? Currently set for 9h on the charge controller and 12h on the ac charger. Would it be helpful to set it for more than 24-48 hours?

I normally suggest holding at 24 hours to give the battery some time to balance.

Typically needs 2+ hours to nearly fully charge at 13.8V. I think the IP22 can be set to work in power supply mode, so you can just set that one to stay at 13.8V. On the MPPT, just set float to .05V below absorption.

After 24 hours, try 14.0V, 14.2V, 14.4V and see if you can induce a BMS protection event. If so, set to the highest voltage it can sustain without triggering protection and hold it there for 24 hours. Rinse and repeat until you can get to 14.4V.

Alternatively, if you can pull full rated capacity by charging to 13.8V without triggering BMS protection, extended dwell times at elevated voltage may not be needed and regular charging to 13.8V+ will improve battery balance over time.

 

[Brucey]

So I have bulk set to 13.8v on both the Victron 100/30 and IP22 12/30. Should I set the absorb time for as long as possible? Currently set for 9h on the charge controller and 12h on the ac charger. Would it be helpful to set it for more than 24-48 hours?

What are the individual cell levels as reported by the powerurus Bluetooth?

I'm running one hour of absorb at 14.4V(dropped it down from recommended 14.6V on my Redodo minis).

Using the settings at the end of this thread:

IP22 charger going straight to Absorption - Victron Community

community.victronenergy.com

 

[Tomthumb62]

What are the individual cell levels as reported by the powerurus Bluetooth?

I'm running one hour of absorb at 14.4V(dropped it down from recommended 14.6V on my Redodo minis).

Using the settings at the end of this thread:

IP22 charger going straight to Absorption - Victron Community

community.victronenergy.com

View attachment 168157

Cell voltages, taken at one of the biggest deltas I’ve seen so far:



When I get home, I’m going to put it on 13.8v constant for 24 hours and see if that triggers the BMS to cutoff. If not, move up to 13.9v and test again, then again at 14.0v and on up to 14.2v, per @sunshine_eggo ’s suggestion.

So far it with the new charge profile on the new Victron MPPT , I’m not getting any BMS cutoffs.

 

[sunshine_eggo]

Cell voltages, taken at one of the biggest deltas I’ve seen so far:


When I get home, I’m going to put it on 13.8v constant for 24 hours and see if that triggers the BMS to cutoff. If not, move up to 13.9v and test again, then again at 14.0v and on up to 14.2v, per @sunshine_eggo ’s suggestion.

So far it with the new charge profile on the new Victron MPPT , I’m not getting any BMS cutoffs.

Recommend you go reverse direction. Start at 14.6V and go down. Several hours at elevated voltage may provide sufficient balancing to eliminate the issue.

 

[Tomthumb62]

Recommend you go reverse direction. Start at 14.6V and go down. Several hours at elevated voltage may provide sufficient balancing to eliminate the issue.

Oh, OK! I’ll try that.

As aside, my math is suggesting that the Victron MPPT is 21-33% more efficient at converting solar to wattage. Max wattage I ever got with the 30A Renogy MPPT was 280w on a 600W system, in ideal conditions about 7 days ago. I just hit 374W on the 30A Victron, in hazy/smoky skies. If this isn’t just a fluke, then Victron upgrade is paying for itself already.

Now one thing is I’m slightly further south than a week ago, but not by much.

 

[Brucey]

Cell voltages, taken at one of the biggest deltas I’ve seen so far:

View attachment 168333

When I get home, I’m going to put it on 13.8v constant for 24 hours and see if that triggers the BMS to cutoff. If not, move up to 13.9v and test again, then again at 14.0v and on up to 14.2v, per @sunshine_eggo ’s suggestion.

So far it with the new charge profile on the new Victron MPPT , I’m not getting any BMS cutoffs.

Using the profile from the Victron community forums?

 

[Tomthumb62]

Oh, OK! I’ll try that.

As aside, my math is suggesting that the Victron MPPT is 21-33% more efficient at converting solar to wattage. Max wattage I ever got with the 30A Renogy MPPT was 280w on a 600W system, in ideal conditions about 7 days ago. I just hit 374W on the 30A Victron, in hazy/smoky skies. If this isn’t just a fluke, then Victron upgrade is paying for itself already.

Now one thing is I’m slightly further south than a week ago, but not by much.

I was wrong, we’re further NORTH, not south. A week ago at 40 degrees, now at 44 degrees. This is a crazy big difference. Definitely the Victron is more efficient. Hit a record a few minutes ago of 389W. Never ever seen that much before.

 

[Tomthumb62]

Using the profile from the Victron community forums?

No. Currently set to 14.0v. But I’m changing it to 14.6v per @sunshine_eggo ’s latest suggestion.

 

[Brucey]

Here's how my Redodos behave on the IP22 (using community profile but absorb set at 14.4V instead of 14.6V).

It will take around 103-104Ah then BMS will disconnect. Then it will sit on absorb mode for an hour and take almost nothing. Then into storage mode where I stop the cycle.

My main concern is keeping the cells in balance as it's a black box on my batts. I'm not worried about getting the final 1% of capacity.

 

[sunshine_eggo]

BTW, the 14.6V is intended to trigger protection. Most batteries will trip protection at 3.65V/cell.

 

[Factsmanmp]

I was wrong, we’re further NORTH, not south. A week ago at 40 degrees, now at 44 degrees. This is a crazy big difference. Definitely the Victron is more efficient. Hit a record a few minutes ago of 389W. Never ever seen that much before.

So you are saying the issues you warned me about…. was a battery issue and not a Renogy charge controller issue?
However you switched from a Renogy to a Victron charge controller and are finding that the Victron is more efficient?

 

[Tomthumb62]

Recommend you go reverse direction. Start at 14.6V and go down. Several hours at elevated voltage may provide sufficient balancing to eliminate the issue.

Ok I’ve tried this a few times now but only on regular solar charging. Started at 14.6v, then 14.4 then 14.2v. Still getting BMS cutoff.

If I change my ip22 charger to power supply mode, will charging at 14.6v at 15 or 30A cause any overcharging? I guess the BMS will prevent that. I think I’m still a bit confused by what you mean to start at 14.6 and work down?

 

[sunshine_eggo]

Ok I’ve tried this a few times now but only on regular solar charging. Started at 14.6v, then 14.4 then 14.2v. Still getting BMS cutoff.

The goal was to establish that you're having balance issues. Issue confirmed.

If I change my ip22 charger to power supply mode, will charging at 14.6v at 15 or 30A cause any overcharging?

No, but it is not regarded as healthy to hold them at elevated voltage.

I guess the BMS will prevent that.

Yes.

I think I’m still a bit confused by what you mean to start at 14.6 and work down?

Wanted to confirm that you were experiencing BMS cut off issues, i.e., not related to the Renogy controller "spiking" The battery is the issue, not the Renogy.

Rather than set the IP22 @ 14.6V, simply set it at 13.8V. 3.45V/cell is less stressful than holding at or near 3.65V and should allow the batteries time to balance. I'd allow for at least 24 hours @ 13.8V. Then see if you get BMS protection at 14.0, 14.2, 14.4 and 14.6V (you can stop at the first one that triggers protection). Give it another 24 hours @ 13.8V and then try again.

EDIT: If 13.8V is a good charge voltage, and you're getting acceptable capacity, you don't need to do anything special - just use it normally, and it will eventually balance out.

 

[Tomthumb62]

The goal was to establish that you're having balance issues. Issue confirmed.



No, but it is not regarded as healthy to hold them at elevated voltage.



Yes.



Wanted to confirm that you were experiencing BMS cut off issues, i.e., not related to the Renogy controller "spiking" The battery is the issue, not the Renogy.

Rather than set the IP22 @ 14.6V, simply set it at 13.8V. 3.45V/cell is less stressful than holding at or near 3.65V and should allow the batteries time to balance. I'd allow for at least 24 hours @ 13.8V. Then see if you get BMS protection at 14.0, 14.2, 14.4 and 14.6V (you can stop at the first one that triggers protection). Give it another 24 hours @ 13.8V and then try again.

EDIT: If 13.8V is a good charge voltage, and you're getting acceptable capacity, you don't need to do anything special - just use it normally, and it will eventually balance out.

Ok thank you so much for detailing that out. The battery was fully charged so I drained it a bit and now have the charger set on power supply mode at 13.8v at the lowest amperage it will allow me to set at 7.5A. I’ll wait 24 hours and see how it goes. Thanks again.

 

[sunshine_eggo]

Ok thank you so much for detailing that out. The battery was fully charged so I drained it a bit and now have the charger set on power supply mode at 13.8v at the lowest amperage it will allow me to set at 7.5A. I’ll wait 24 hours and see how it goes. Thanks again.

It will taper current once it hits 13.8V.

 

[Tomthumb62]

It will taper current once it hits 13.8V.

Ok! I didn’t know that. I hadn’t used power supply mode before and assumed it would push the amps unlike charger mode. But now I remember that current is pulled not pushed.