Need help to charge simpliphi batteries

[Venezuela Solar]

Recently i bough a PIP 3048LV MK and a simpliphi 3.8kwh 48v (51v), simpliphi does not have a profile for the PIP and recommends using a 2 stage charger, so you know the PIPs are 3 stage algorithm, checking other inverters settings, like solark, Victron and outback, i get this voltages, 54.4 for absorption (in some cases it provides absorption time) and 54v float (as a place holder, float is disabled, but as a recommendation) so I'm thinking on setting the bulk to 54.4v, the float to 54 and cutoff voltage to 50.2v (80% D.O.D at c/2 by the manufacturer and recommended cutoff voltage)

It worries me to damage the batteries, by overcharging or not charging it completely, i also plan on using a watt meter for the battery so i can confirm how many watts go in after i discharge it to 50.2 at c/2

 

[svetz]

Can you turn off the float in the PIP? Here's what I saw in the SimpliPhi manual:


If you can't turn off the float, perhaps there's an "integration guide" as mentioned in the bottom note?

 

[Venezuela Solar]

Can you turn off the float in the PIP? Here's what I saw in the SimpliPhi manual:

View attachment 26951
If you can't turn off the float, perhaps there's an "integration guide" as mentioned in the bottom note?

Actually that's the integration guide I'm using, I think I can't turn off the float charge, that's the problem, i will continue digging into the PIP, but at least on first sight I can't find a way to turn it off

What could happen if it continues charging with float?

 

[svetz]

...What could happen if it continues charging with float?

Overheating the cells and premature death. Lithium doesn't mind being fully charged, but it doesn't like staying that way. I only use mine for emergency reserve power as I have a nice net-metering agreement... so unless there's a storm brewing I usually keep them at 70% during hurricane season and am planning on less for the off-season. See https://diysolarforum.com/threads/soc-degradation-of-lifepo4.13215/ for more.

What did PIP say about turning off the float? It's very common to need to do that for LiFePO4, they should have some way of doing it.

 

[Venezuela Solar]

Overheating the cells and premature death. Lithium doesn't mind being fully charged, but it doesn't like staying that way. I only use mine for emergency reserve power as I have a nice net-metering agreement... so unless there's a storm brewing I usually keep them at 70% during hurricane season and am planning on less for the off-season. See https://diysolarforum.com/threads/soc-degradation-of-lifepo4.13215/ for more.

What did PIP say about turning off the float? It's very common to need to do that for LiFePO4, they should have some way of doing it.

I just sended them a mail

 

[Venezuela Solar]

Overheating the cells and premature death. Lithium doesn't mind being fully charged, but it doesn't like staying that way. I only use mine for emergency reserve power as I have a nice net-metering agreement... so unless there's a storm brewing I usually keep them at 70% during hurricane season and am planning on less for the off-season. See https://diysolarforum.com/threads/soc-degradation-of-lifepo4.13215/ for more.

What did PIP say about turning off the float? It's very common to need to do that for LiFePO4, they should have some way of doing it.

Here in venezuela we use it daily or weekly at least, lights go out all the time

 

[Venezuela Solar]

Overheating the cells and premature death. Lithium doesn't mind being fully charged, but it doesn't like staying that way. I only use mine for emergency reserve power as I have a nice net-metering agreement... so unless there's a storm brewing I usually keep them at 70% during hurricane season and am planning on less for the off-season. See https://diysolarforum.com/threads/soc-degradation-of-lifepo4.13215/ for more.

What did PIP say about turning off the float? It's very common to need to do that for LiFePO4, they should have some way of doing it.

Just received an email from Mppsolar, they say i should set float = bulk, I'm currently testing this, but Ian Roux, from Mppsolar USA told me to set the float to battery nominal voltage, in this case would be 51v, not sure which one is better

 

[svetz]

Just received an email from Mppsolar, they say i should set float = bulk, I'm currently testing this, but Ian Roux, from Mppsolar USA told me to set the float to battery nominal voltage, in this case would be 51v, not sure which one is better

As long as the float voltage is less than or equal to the cutoff-charge voltage no current will flow and since you're using it daily either is probably fine. Hopefully if one is actually better than the other someone more knowledgeable will give you something more than their best guess and an explanation (then we can both learn!)