EG4 limited charging with LV5048

[AI6MK]

Hi,

I have an off-grid setup to power my well/boost pumps. We live in rural California, with abundant sunshine.
The system comprises:
1. 16 x 325W panel ground mount
2. LV5048
3. 2 x EG4 batteries (10KW total)
4. Load is PUMPs + BARN (Lighting and miscellaneous appliances, Fan, Fridge etc)
System works generally very well and I finish the day with a tank full of water (2500 gallons) and full batteries. Overnight I turn off the well pump and in the morning the batteries are at ~50% SOC. I monitor the LV5048 using SOLAR ASSISTANT.

I configured the LV5048 with solar as the priority. I expected that the batteries would get charged as a priority as soon as I get good solar.
But, even with good sunshine, and no large loads, the SOLAR panels are throttled and typically only provide 10A charging current for the batteries. If I add loads the solar can easily provide the additional power so there appears to be plenty of unused solar capacity.

So question is:
What do I need to modify in the LV5048 to charge the batteries at say 50A MAX (25A each) ?

LV5048 Key Parameters are:
01 - SBU
02 - 100A (Max charging current)
05 - USE
11 - 50A (Max utility charging current)
16 - CSO

LV5048 PARAMETERS
	BATTERIES	EG4	2pcs
	DATE	1-Oct-23​
Program	Value	Description	Units
0	ESC
1	SBU
2	100		A
3	APL
5	USE
6	LRE
7	TRD
8	120		V
9	60		Hz
11	50	UT1	A
12	51.0		V
13	FUL		V
16	CSO
18	BON
19	REP
20	LON
22	AON
23	BYD
25	FEN
26	56.8	BULK	V
27	54.0	FLOAT	V
28	2A2
29	44.6		V
30	ONE
31	SBE
32	AUT
33	EDS	EQUAL
34	54.0	EQUAL	V
35	60		MIN
36	120		MIN
37	30D		DAYS
39	ADS

LV5048

 

[AI6MK]

Well, looks like this is an old probem with LV5048, which MPP Solar has not addressed. This may have no effect on your buying choices, but I have to say it doesn't fill me with confidence.

The problem is related to Program 32, BULK CHARGING TIME, which is set to AUT (AUTO) and limits the battery charging current to 10A. No idea why it's 10A. If I select a fixed value, say 60min, the charger now provides 60A, as expected. I may need to increase this value depending on the initial SOC of the batteries.

Once the battery reaches 100% SOC, the charging voltage is changed to the FLOAT VOLTAGE which in my case is set to 54.0V and the charging current reduces, eventually to 0A.

 

[Zapper77]

Well, looks like this is an old probem with LV5048, which MPP Solar has not addressed. This may have no effect on your buying choices, but I have to say it doesn't fill me with confidence.

The problem is related to Program 32, BULK CHARGING TIME, which is set to AUT (AUTO) and limits the battery charging current to 10A. No idea why it's 10A. If I select a fixed value, say 60min, the charger now provides 60A, as expected. I may need to increase this value depending on the initial SOC of the batteries.

Once the battery reaches 100% SOC, the charging voltage is changed to the FLOAT VOLTAGE which in my case is set to 54.0V and the charging current reduces, eventually to 0A.

Sounds like the inverter is charging the batteries like they are lead. Are you able to use battery communication?

 

[AI6MK]

Zapper, thanks for your comment. It appears to be a bug with charging caused by parameter 32 set to AUT (auto).

Changing from AUT to a fixed amount, 60 mins in my case, fixes the charge current issue and allows the solar panels to operate at full power.

Batteries are LiFePO4 and I do monitor them using Solar Assistant. In all other respects they perform as expected and I do have battery type set to USE (User) which gives me full control.

I am surprised that I put up with it for so long. My solar array, which can produce 4KW was never realizing it’s true potential charging my 2 x EG4 batteries. But now with 32 set to 60 min, I ‘m getting up to 60A during bulk charging phase.

I cannot find any explanation from MPP Solar what is supposed to happen with 32 set to AUT(auto), but it appears to be a bug they never fixed. The LV5048 is a legacy product now and I’m pretty sure they will not work on a software patch to resolve it but I’m happy now that I can unleash the capacity of my ground mount.