Confusing battery settings

[livingthefreeway]

Hey All.
I have (4) 12v 300ah Enjoybot brand batteries hooked up in series to power a 48v Victron system. I’m trying to understand what are the optimum charge settings for the battery, and although the manufacturer was quick to respond with specs when I emailed them, some of the numbers seem like they might be a bit off.

Hoping someone else can take a look and confirm or deny my suspicions.

Here’s the specs sent over from Enjoybot to plug into my Victron system:
DC Input Low voltage shutdown: 51.40v
Absorption voltage: 58.40v
Repeated absorption time: 12.00 (hours)
Float voltage: 55.2v
Repeated absorption interval: 1.00 (days)
Charge current: 20A recommended. 50A Max (amps)
Absorption time: 2.00 (hours)

Charged voltage: 53.60v
Tail current: 2.0% (percentage)
Charged detection time: 30min (minutes)
Peukert exponent: Default
Charge efficiency factor: 100% (percentage)
Current threshold: Default
Time-to-go averaging period: Default
Time-to-go discharge floor: 20% (percentage)

By comparison, here is Enjoybot’s spec sheet for their all-in-one 48v battery
That spec sheet is for just one 48v battery (with one singular BMS), so not sure if there should be any difference in my settings run (4) 12v batteries in series.

In general, do these specs from the manufacturer look right?

Specifically the charged voltage of 53.6v seems rather low, as well as the inverter low voltage disconnect of 51.4 both seem rather conservative.

I know this is what I get for going with a ‘no-name’ battery manufacturer. But it was the only option available to me at the time.

Thanks for any input you can share

 

[sunshine_eggo]

Pretty much all LFP:

1. Fast charge: 3.55-3.65V/cell 15-30 minutes absorption (best for generator charging, and you should consider setting absorption time to 1m to avoid charging inefficiently)
2. Slow charge: 3.45V/cell, 2 hour absorption (may see improved cycle life)
3. Float: 54V

DC Input Low voltage shutdown: 51.40v

48V

Absorption voltage: 58.40v

see above

Repeated absorption time: 12.00 (hours)

disable or lengthen to max.

Float voltage: 55.2v

see above

Repeated absorption interval: 1.00 (days)

Disable or lengthen to max.

Charge current: 20A recommended. 50A Max (amps)

Seems CRAZY low unless this is per battery.

Absorption time: 2.00 (hours)

See above

Charged voltage: 53.60v

0.3V below whatever absorption voltage you choose.

Tail current: 2.0% (percentage)

Fine

Charged detection time: 30min (minutes)

3

Peukert exponent: Default

1.05

Charge efficiency factor: 100% (percentage)

99

Current threshold: Default

.01A

Time-to-go averaging period: Default

Yep

Time-to-go discharge floor: 20% (percentage)

Personal preference. This only means that when you look at the shunt, and it's discharging, it will report the time remaining until 20% is hit.

Specifically the charged voltage of 53.6v seems rather low, as well as the inverter low voltage disconnect of 51.4 both seem rather conservative.

They're likely following guidelines for AC charging that specify 0.3V below float. I prefer using absorption voltage to avoid potential false syncs to 100% when charging with solar.

Critically important that you charge all 4 12V to poked full individually - watching for odd behavior like BMS charge protection events - and then again in parallel for maybe 24 hours. you need all 4 12V to be at true 100% when you string them in series.