question

That datasheet is interesting. Took me a while...

From the graphs, you have the choice of charging to 2,27 or 2,4V/cell. Note the current limitations.

Configured at 48V nominal, you have 24 cells, so set absorption voltage to either 24 * 2.27 or 24*2.4. Your choice. What happens is the charger will push at it's max current until the absorption voltage is reached. Then it maintains that voltage. Their graphs correspond with this. What they also show is that charge times vary with DOD. Leaving your charger on adaptive should be OK. Max absorption time can be inferred from the graphs from the point of max voltage forwards. The default of 8 hours should fit well, but increasing won't be a bad thing. Usually it'll be a lot less in adaptive.

Repeated absorption I'd leave at defaults, unless you can get a clear statement from the makers.

They don't give a float voltage. I'd be tempted to charge at 2.27 to be safe, and set float a little lower, say 2.25.

If the current doesn't get too high, try charging at 2.4V and check the current.

I'd also watch the DOD/cycles. Quite a big improvement in life if you limit DOD to 30%.

On capacity, it's a touch misleading. We usually work from the C20 value as a starting point. IF you have very low current draw, you can set it higher.

Temp comp they only give for capacity. What's of interest here for charging is the Voltage change with temperature per degreee C. For now, leave at default. unless you get a better answer. Note that battery voltage decreases with temperature, for the same state of charge.

@kevgermany "accurat" is a home brand of "autobatterien-billiger" (batterium GmbH)

What specifically should I ask them to fill in the blanks?

95Ah (C10 discharged to 10,5V) at 48V is way to less for a 5000VA MultiPlus.

You will not get happy with that system.

Basically all the open questions.

Temp compensation, peukert, float, what's the real difference between charging at 2.4 and 2.27V, sustained discharge current. Matthias is right, I should have noticed the batteries are too small - 5KW is in the 100Amp region. Also rough indication of voltage under discharge conditions for your alarms. But if you don't have a BMV your alarms are very approximate.

The OEM-vendor (batterium GmbH) cannot provide any other information :-(

We have a Raspberry Pi with Touchscreen, Venus OS and DVCC enabled. Do we really need a BMV or is Venus OS capable to aggregate the values of the SmartSolar MPPT and the Multiplus II to get correct voltage/currente/charge state readings of the battery?

Which configuration values do you suggest for a safe operation until I have found a suitable battery (probably LiFePo).

Thanx for any hint! :-)

For the battery, as long as you stick to what you have, should be OK. But state of charge is going to be inaccurate. All the charging is voltage based.

So you're guessing the alarm level. As you probably know, when you put a load on a battery, voltage drops. When load goes off voltage climbs. Maybe warn at 12V, but no idea really, sorry.