Costco Interstate GC8 for solar

[carleriksen]

I was considering going Lithium, but I have the opportunity to purchase some less than one year old Costco Interstate GC8 for a very good price.

Does anyone have experience using these particular batteries for solar?

EDIT:
I realize I am a bit light on info here. As mentioned it is a Golf Cart 8V battery; which is a deep cycle albeit probably on the cheaper end of the scale. To be useful at 8V the system will have to be at least 24V, which is what I have so good there.

On the 'good price' aspect the offer is for 6 of them, which would make a 2P3S 24v configuration, for $540.
They are of 7/23 manufacture. Price is about half what it would cost to pick them up new.

 

[Ampster]

Does anyone have experience using these particular batteries for solar?

I do not have any experience but they are probably not rated for deep cycle use and may not last very long if used in that application. Lithium is more costly out the door but you can use more of the capacity and they will last thousands of full cycles which could be 8-10 years.
EDIT: On further investigation, GC stands for golf cart which means they are designed for deep cycle. Whether that means more than 50% you would have to verify. I still believe, long term, Lithium is a better value.

 

[OzSolar]

I was considering going Lithium, but I have the opportunity to purchase some less than one year old Costco Interstate GC8 for a very good price.

Does anyone have experience using these particular batteries for solar?

The Trojan T105 golf cart battery has been the staple of solar PV since the beginning of solar PV. Not because they were great but because they were the best thing that was available. There's no telling how well a 1yr old Costco golf cart battery compare the classic T105 but I suspect they are lower quality.

If these are a GREAT deal more than likely they will be a fine first set of batteries but keep in mind you'll have to regularly add distilled water to them and they do put off a bit of stink when charging.

 

[seneysolar]

I was considering going Lithium, but I have the opportunity to purchase some less than one year old Costco Interstate GC8 for a very good price.

Does anyone have experience using these particular batteries for solar?

Golf cart batteries are decent for solar. As you have discovered, its hard to ignore the cost. I think brand new those costco interstates are $120 each @ 210+ AH. Easily to get and warranty nationwide. Lots of folks use them.

No they dont perform to LFP standards, but you wont have to fuss with a BMS and they dont really care about temperature as long as they are charged. You wont get 10 years life like LFP, but 5 is not unreasonable, depending on how you treat them.

 

[grizzzman]

I was considering going Lithium, but I have the opportunity to purchase some less than one year old Costco Interstate GC8 for a very good price.

Does anyone have experience using these particular batteries for solar?

Are 8 volt batteries going to work for what you wanna do??

 

[carleriksen]

Are 8 volt batteries going to work for what you wanna do??

Yes, System is 24V so that will work

 

[dopeassjackson]

I have cheap ass Sam's club GC2 batteries going on 3yrs in a weekend cabin. They see temps 0*f many times each winter. They still work great. I have 2S3P for a total of 6 batteries, they generaly take about 1gal of water a year total. I have never ran a desulphate charge on them.

they are hooked up to a charge controller year round.