Needing new batteries and looking for help

[Blyth]

Hi,

I'm new to the forum and new to solar. Like extremely new. We recently bought a house that has an old 4kw grid-tied system installed. I'm guessing that the system was installed 20 years ago, but there is no date included with the documentation. The batteries are no good at all. In order to use the system, long story short, there is a process that we have to go through with the co-op. At any rate, the batteries need to be replaced. There is a total of 16 Exide PV 27 batteries... I'll just list it how it's listed in the documentation:

BATTERIES
16 Exide PV 27
12 Volt 600 Amps 105 Amps Reserve

4 Rows in Parallel of 4 Batteries in Series
48 Volts 9,600 Amps 1,680 Amps Reserve

Total Reserve Watts 80,640 Watts DC
76,608 Watts Inverted to 125 Volts AC

I was thinking of going to LiFePO4 batteries and just making my own battery banks. While I can diy the batteries without issue, I do not know how to do the math(yet) to figure out how many I would need to equal what the system was originally fitted with. At the moment, We cannot afford to just go buy 16 batteries that are the same as what the system currently has. I have done some searching on the forum and will continue to do so. I am all about learning and I'm going to have to as I'm going to be building a shop later this year and it will be powered strictly by solar. However, I would like to get this battery situation taken care of as quick and as cost effective as possible. I do have a lot to learn. I appreciate any help, feedback, direction, or suggestions that anyone may have. I do plan to upgrade the system in the future to catch up with the times/technology... I want to educate myself more before doing that. Not to mention, the hoops I'll have to jump through(if any) with the stupid co-op when I do upgrade. Thanks!

 

[Tomthumb62]

Hi,

I'm new to the forum and new to solar. Like extremely new. We recently bought a house that has an old 4kw grid-tied system installed. I'm guessing that the system was installed 20 years ago, but there is no date included with the documentation. The batteries are no good at all. In order to use the system, long story short, there is a process that we have to go through with the co-op. At any rate, the batteries need to be replaced. There is a total of 16 Exide PV 27 batteries... I'll just list it how it's listed in the documentation:

I would suggest posting more specs of your system. Such as your charge controller: make, model number and a link if you can find one for it. You may or may not need other upgrades before switching to lithium. That's about as much as I know and hopefully someone more knowledgeable will chime in.

 

[DIYrich]

Assuming 600 cranking amps and 105 amp hours, you have 48v @ 420 amps of lead acid, giving you 210 amps max usable.

That would imply 200 ah of LiFePO4 batteries, assuming that 5,000 watts continuous is all you need.

 

[JWLV]

20 years old? Solar panels made two decades ago are expected to reach its end of life around 20-25 years. They are probably on its last legs. If it's a 4kw system, it is likely that after 20 years, it is only producing 0.5kw to 1kw.

 

[Blyth]

20 years old? Solar panels made two decades ago are expected to reach its end of life around 20-25 years. They are probably on its last legs. If it's a 4kw system, it is likely that after 20 years, it is only producing 0.5kw to 1kw.

Those are my first on the list to upgrade.

 

[Blyth]

I would suggest posting more specs of your system. Such as your charge controller: make, model number and a link if you can find one for it. You may or may not need other upgrades before switching to lithium. That's about as much as I know and hopefully someone more knowledgeable will chime in.

I am sure that it is a totally outdated system. I do have intentions of upgrading the whole system as funds are available. Maybe I should look more at prioritizing things as far as what to consider upgrading first. Though, I would like to get some sort of batteries in there, just so that it is a complete working system. I attached pics if it helps.

 

[Blyth]

Assuming 600 cranking amps and 105 amp hours, you have 48v @ 420 amps of lead acid, giving you 210 amps max usable.

That would imply 200 ah of LiFePO4 batteries, assuming that 5,000 watts continuous is all you need.

Thank you for the info!