Hi all,

I have a solar system GW5048-ESA consisting of one hybrid inverter 5 kW and two batteries SECU-A5.4L with a total capacity 10.8 kWh. Can I add one more battery SECU-5.4L to the specified system?

3 hours ago, kire said:

Hi all,

I have a solar system GW5048-ESA consisting of one hybrid inverter 5 kW and two batteries SECU-A5.4L with a total capacity 10.8 kWh. Can I add one more battery SECU-5.4L to the specified system?

Generally Yes, however there are a few conditions.

How old are the existing batteries? If they are less than two years old it should be ok.

The new battery has to be identical to the old ones. (chemistry, voltage, capacity, etc)

The old ones will charge and discharge slower than the new one, thus giving the new battery a bigger workout, but over time they should even out.

3 hours ago, kire said:

Can I add one more battery SECU-5.4L to the specified system?

You can ad as many batteries as you like. The more the better. All you have to do is to adapt the max charging current setting.

They have to be identical in chemistry and number of cells, but may have different capacity.

Edited August 29, 20241 yr by Beat

1 hour ago, HendrikBigChief said:

Generally Yes, however there are a few conditions.

How old are the existing batteries? If they are less than two years old it should be ok.

The new battery has to be identical to the old ones. (chemistry, voltage, capacity, etc)

The old ones will charge and discharge slower than the new one, thus giving the new battery a bigger workout, but over time they should even out.

Existing batteries are 1 year old. The batteries are the same.

1 hour ago, Beat said:

Можете да рекламирате колкото искате батерии. Колкото повече, толкова по-добре. Всичко, което трябва да направите, е да адаптирате настройката за максимален ток на зареждане.

Те трябва да бъдат идентични по химичен състав и брой клетки, но могат да имат различен капацитет.

 Instead of two modules, three modules will be used. The maximum current according to the table will be 100 A. It remains unchanged.

@kire,

the 100A spec is the max charging rate for each battery. I would not recommend 100A charge (per battery), that would work the battery very hard, and effect it's longevity.

If you are only charging by Solar, then the amount of kW of PV you have will determine the rate of charge (minus your loads), irrespective of your inverter's charge setting. Sometimes inverters have a separate charge setting for Grid Charging.

Depending on your needs, anything between 60 - 150 A should be sufficient. And remember, that number is the Total charge current for all 3 batteries, therefor recommendation is between 20 - 50 A per battery.

@kire, how do cyrylic characters get into my quote?

Almost all manufacturers limit the max charge and discharge currents to 1C. But that should only be used in extreme situation. I limit my grid charge current to 0.1C. On the other hand I set the total charging current limit very high in order to catch all the available solar power. With the actually installed PV panels there is no chance that they even reach 0.5C.

3 hours ago, Beat said:

@kire, how do cyrylic characters get into my quote?

Almost all manufacturers limit the max charge and discharge currents to 1C. But that should only be used in extreme situation. I limit my grid charge current to 0.1C. On the other hand I set the total charging current limit very high in order to catch all the available solar power. With the actually installed PV panels there is no chance that they even reach 0.5C.

I personally charge at max 0.2C and I also lowered my charging voltage, the combo of those two should make the batteries last quite a long time.

 Cyrillic was in my quote because I use a translator. I apologize for that.