LV6548 with 48/51.2V 110AH trophy battery - setting to use utility to increase voltage

[pulper11]

Hello - I have the LV6548 inverter with a 48/51.2V 110AH trophy battery. I have the LV6548 currently setup so that when the battery goes to below 51V, the utility power kicks in until it gets to 54V. 51V is the highest number for this setting.

During winter months my battery will hover around 52V. I know that isn't good for the battery to not be increased for a while (I've been told it should happen every couple days).

Other than simply using as much power as I can to get the battery below 51V, is there a setting on the LV6548 where I can tell it, no matter what the voltage of the battery is now, to increase it up to 54V?

Hope this makes sense! Thank you.

 

[timselectric]

You won't do any damage to LFP batteries, as long as the voltage stays between 2.5v and 3.65v per cell, and the temperature stays in the comfortable range for humans.
Getting to a full charge regularly let's the BMS balance the cells.
Which is how you get the maximum capacity from the batteries.
But at 54v on a 16s battery, you aren't getting above 3.45v for cell balance, anyway. So, it doesn't matter how long you go between 54v charges.
I just came off of a 3 month run without a full charge. (winter production sucks)
It took about 24 hours for my active balancing to wip my batteries back into shape.
It's nothing to worry about, just some lost capacity until balanced again.
Just keep in mind that more time without balancing, means less capacity available.

 

[pulper11]

Thanks Tim for the reply! I have a couple questions then:
1. Are you saying that I should set it to 55V or higher?
2. I saw in another post that it matters how long you stay at the full charge. However, when mine charges and hits 54V (or if #1 above - 55V), it immediately stops charging and drops down to (I'm assuming) the float voltage at around 53 to 53.5 or so. How can I get it to stay at 54/55V for a specific amount of time using utility power?
Thanks!!
Paul

 

[timselectric]

1. Are you saying that I should set it to 55V or higher?

55.2v minimum for any meaningful balancing.

2. I saw in another post that it matters how long you stay at the full charge.

I wouldn't leave it full indefinitely. You need to test the capacity from time to time, just to make sure it's ready when you need it.
I just went through a winter storm and held my battery bank at 57v for 2 weeks.
LFP cells don't have memory. And as long as you don't push them outside of their temperature and voltage ranges, I don't see anything to worry about.
I know that not everyone agrees with that, but I have seen no degradation from the way that I do things. And I test the capacities yearly.

 

[pulper11]

55.2v minimum for any meaningful balancing.

I wouldn't leave it full indefinitely. You need to test the capacity from time to time, just to make sure it's ready when you need it.
I just went through a winter storm and held my battery bank at 57v for 2 weeks.
LFP cells don't have memory. And as long as you don't push them outside of their temperature and voltage ranges, I don't see anything to worry about.
I know that not everyone agrees with that, but I have seen no degradation from the way that I do things. And I test the capacities yearly.

Thanks again Tim! Hopefully this is my last question here: Would I keep it at 55.2V (for say 24 hours) by changing the float to 55.2V?

 

[timselectric]

Thanks again Tim! Hopefully this is my last question here: Would I keep it at 55.2V (for say 24 hours) by changing the float to 55.2V?

Yes
You will also have to raise the bulk charging to above that, for the settings to be accepted. Usually at least 0.5v higher is enough for most units.

 

[pulper11]

Thanks! I'll give it a try.

 

[pulper11]

I actually forgot my original question! Hope there is an answer to this:
Other than simply using as much power as I can to get the battery below 51V, is there a setting on the LV6548 where I can tell it, no matter what the voltage of the battery is now, to increase it up to full charge (using utility)?
Thanks!

 

[timselectric]

I actually forgot my original question! Hope there is an answer to this:
Other than simply using as much power as I can to get the battery below 51V, is there a setting on the LV6548 where I can tell it, no matter what the voltage of the battery is now, to increase it up to full charge (using utility)?
Thanks!

Possibly, if it has some kind of timer settings.
I'm not familiar with all of its settings.