Need help with info regarding J185HG-AC Trojan batteries

[sleepless]

A local dealer has offered these batteries at a highly discounted rate, saying they are "old stock" but have been regularly recharged. He is offering a 1-year free replacement warranty. He offered to run a full test on the batteries when they arrived to ensure their health. In Canada, batteries are really expensive, so if you live here you'll recognize that this is a great price ($240.00 CAD + no core fee).

https://www.kijiji.ca/v-view-details.html?adId=1413948777&requestSource=b

I am interested in the J185HG-AC. they are 12V, 225AH@20hr flooded deep-cycle batteries.

https://www.trojanbattery.com/products/deep-cycle-agm-2/ac-series/

https://www.trojanbattery.com/product/j185hg-ac/

I'd like to buy 4 of them and connect them for a 24V system, together with my 1040W panel array, and 40A MPPT charge controller. my old 6V golf cart batteries were purchased in 2011, and are at the end of their life.

The L16HG-AC (6V, 435AH@20hr) are also an option, but are $80 more expensive each at $320 (x4 = $320 more) for slightly less total amp hours.

I've been researching online, but Trojan doesn't give much info on this lineup of batteries (AC Series), other than that they are manufactured for floor cleaning machines/equipment (FM). Many of these series are also rated for aerial work platform/access equipment (AW). However, some other batteries in this same lineup also seem to be rated for renewable energy use (RE) according to the web-page specifications, but not listed in their renewable energy brochure:
J185H-AC https://www.trojanbattery.com/product/j185h-ac/
J305H-AC https://www.trojanbattery.com/product/j305h-ac/
J305P-AC https://www.trojanbattery.com/product/j305p-ac/ *also specified for electric vehicle/golf cart use (EV)
L16HG-AC https://www.trojanbattery.com/product/l16hg-ac/ *oddly, web-page specifications show only RE (renewable energy), and not FM (floor machines). Error?

The J305H-AC, L16H-AC, J185H-AC are also rated for RV/marine use (RM).
https://www.trojanbattery.com/pdf/Tr...R_brochure.pdf.

The J305P-AC, J305H-AC, J185P-AC, J185H-AC, are all listed under their signature series and rated for 1200 cycles @ 50% DOD.

https://www.trojanbattery.com/products/deep-cycle-flooded/signature-line-flooded-2/

One battery in the AC series is even rated for electric vehicle/golf cart use (EV). I'm wondering if the batteries in this series are really all that different internally, so as to be rated for different uses, and how much the physical size/dimensions and terminals play a role.

It would seem that the J185H-AC is basically identical to the J185HG-AC, except for the terminals and casing. I'm thinking the two are likely similar internally and would have a similar life-cycle rating. this would mean that the J185HG-AC should be fine for solar use as well.

http://www.trojanbattery.com/pdf/datasheets/J185HGAC_Trojan_Data_Sheets.pdf

http://www.trojanbattery.com/pdf/datasheets/J185HAC_Trojan_Data_Sheets.pdf

I've contacted their technical support, but haven't had a response. I wanted to know their warranty for this battery, and if it would apply in this case, as I'm unsure if this store is a licensed dealer. I also wanted to know if these batteries could be used in solar applications, and what their rated life-cycle was. It seems Trojan rates the life-cycle of almost all of their batteries, but not these ones.

I have some questions with which your help would be appreciated:
1) Is it a bad idea to purchase old stock flooded batteries in general?
2) Does anyone know what the life-cycle of these batteries might be, and are manufacturer rated life-cycles (at 50% DOD, for example) actually accurate?
3) What are your general opinions on these specific batteries for solar use?

Thanks.

[Mike90250]

Batteries, when manufactured, begin the time clock ticking toward failure. How old are the old stock batteries ? More than 2 years old, and I'd pass, because they only have 2 or 3 years left - trust me, this car was only driven to church on sundays by an old lady

[sleepless]

I'm hoping that Trojan's have a date of manufacture written somewhere on the battery.

I thought that a battery, unused, and topped up regularly would be close to new. I mean, a battery that's rated for 1200 cycles at 50% DOD, goes up to 3000 cycles at 20%. It seems that without use, they discharge fairly slowly (obviously dependant on conditions, temperature etc...) so even if they went down 20% or so, that wouldn't affect them too much.

I really don't understand what exactly a cycle entails though. If a battery slowly discharges on its own over the coarse of a few months, then gets fully recharged, is that one cycle? What if you discharge it with use to 50%, then you encounter some clouds and it takes a few days to fully charge? How many cycles does that count as. I find the cycle ratings confusing.

Thanks for your input. Once the batteries arrive, I'll have a look at his test results and look at the date of manufacture before deciding. Not gonna lie though, this would be a hard one to say no to.

Is there any way to visually see if there's any sulphation going on, indicating poor maintenance? Will testing show an accurate picture of their condition?

[Mike90250]

sulphation shows up as lower specific gravity, with some of the sulfur being tied up in crystals on the plates, instead of being in solution

[inetdog]

sulphation shows up as lower specific gravity, with some of the sulfur being tied up in crystals on the plates, instead of being in solution

Specifically low SG once the battery will not accept any more charge, as confirmed by watching voltage during charging process. The SG cannot rise to the fully charged SG specified by the manufacturer for the battery.

[Mike90250]

yikes. Capitan Obvious (me) missed stating: Make sure you fully charge the battery BEFORE testing the SG, if its still low, perform an EQ charge (it varies between brands of voltage and duration) and if the SG still has not recovered to normal, the battery is done for.

[sleepless]

Ok, so the data sheet states 1.277 SG @ 100% charged.
What would be an acceptable reading, meaning the battery has at least 95% of its cycle life left? That would mean a 1200 cycle@ 50% DOD battery would have at least 1140 cycles left, which is acceptable to me.

Also, my charge controller can't be manually adjusted. It has default settings for Gel/Sealed/Flooded, and that's it:
Charge Controller 12V: Bulk = 14.6V, Float = 13.8V, Equalize = 15.5V (120 minutes/28 days)
J185HG-AC Data 12V: Bulk = 14.82V, Float = 13.5V, Equalize = 16.2V

The temperature compensation settings can be set to match.

Could this be a problem and potentially reduce the life of the battery, and if so how much?
Any thoughts about this specific type of battery?

Thanks.

[Mike90250]

Your battery data sheet should have a chart for SG vs SoC. Anything I invent would be a wild guess.

https://batteryuniversity.com/learn/article/how_to_measure_state_of_charge

Scroll down to the hydrometer section and look at their chart: Hydrometer

The hydrometer offers an alternative to measuring SoC of flooded lead acid batteries. Here is how it works: When the lead acid battery accepts charge, the sulfuric acid gets heavier, causing the specific gravity (SG) to increase. As the SoC decreases through discharge, the sulfuric acid removes itself from the electrolyte and binds to the plate, forming lead sulfate. The density of the electrolyte becomes lighter and more water-like, and the specific gravity gets lower. Table 2 provides the BCI readings of starter batteries.