48 volt battery bank actually 56 volt

[Bendesa1962]

Hi all,

I have a 48 volt battery bank. It's a hybrid PV System and the battery bank is only used as a backup when utility drops out. 4 x 12V 150 Ah. After installation the battery bank constantly gives 56 volts.

Can this damage the battery bank?

Is it dangerous ?

Many thanks to all

[Ampster]

Constantly? Day and night? What is the chemistry of your battery bank? Can you disconnect your inverter and let the batteries rest for a couple of hours and then measure voltage? Or turn off the power to put the system in backup mode and then measure the voltage.

[SunEagle]

Hi all,

I have a 48 volt battery bank. It's a hybrid PV System and the battery bank is only used as a backup when utility drops out. 4 x 12V 150 Ah. After installation the battery bank constantly gives 56 volts.

Can this damage the battery bank?

Is it dangerous ?

Many thanks to all

That voltage may be a little high for a resting 48V system but it should come down a few volts which is typical of a battery.

It all comes down to what voltage range your inverter or loads can handle. If 55V is the limit then you could have a problem but 56V may be ok.

[Fordtrucksforever]

Since that battery bank is for backup there is no load on them. The open voltage will be that high especially if batteries are fairly new. My 48 volt bank is currently wired for 24 until another inverter gets here. When batteries are fully charged up without any load during sunlight hours stay at 28V. Batteries are now just over 7 years old and still show less than 2% sulfating. My controller shows 57.6 absorption and 55.2 float.

[Ampster]

Since that battery bank is for backup there is no load on them. The open voltage will be that high especially if batteries are fairly new. My 48 volt bank is currently wired for 24 until another inverter gets here. When batteries are fully charged up without any load during sunlight hours stay at 28V. Batteries are now just over 7 years old and still show less than 2% sulfating. My controller shows 57.6 absorption and 55.2 float.

My hybrid inverter has an overhead that can be as much as 300 Watts. That is why I suggested disconnecting the inverter but I think his concerns should be minimized by most of the above comments. Thanks for clarifying the voltage settings.

[sdold]

it sounds like that is the setting for a float charger, but might be a little high. In our AGM systems it's usually around 54-55 volts when on a float charger.