Brand new, but tragically dead Trojans

sunshine_eggo

Happy Breffast!
Joined
Oct 26, 2021
Messages
901
Location
USA
If you are willing to monitor all the individual 6V like a hawk (6V in parallel only need one measurement), go for it.
 

Netsua

New Member
Joined
Jul 22, 2021
Messages
56
Did you measure the voltage yet?
Well, pleasantly surprised tonight. I couldn’t find my hydrometer anywhere (my primary bank is Li). But I tested with my multimeter and all but 2 batteries tested at 6.2V - which according to Trojan data sheet is only 70%.

That’s a testament to Trojan in my opinion. These things have been neglected in full sun for every bit of 5 months!

I have 4 20amp 6V chargers on the way from Amazon. I’m going to charge each individually to a full charge and then get them setup with disconnects on my inverters as a manual backup.

I’m super excited, thank you everyone for your help. It sounds like even if they aren’t toast now, I likely would have taken another step that way had I attempted to charge all 24 batteries at once.
 

Netsua

New Member
Joined
Jul 22, 2021
Messages
56
Charged up each individual battery to a full SOC. Wired them up into series parallel this evening and currently putting 57 volts on them all together. Will hook up to primary system tomorrow and equalize - but all appears to be going well so far.
 

sunshine_eggo

Happy Breffast!
Joined
Oct 26, 2021
Messages
901
Location
USA
Nice. That's the maximum deviation you want to see, but it's not horrible given the sit-time. Still confident that this event should mostly be a non-issue once equalized.

If you have the option, an extended dwell at the float voltage (6.75V) might help "equalize" them gently. I have an abused 2S2P (6V batteries) 12V Rolls bank that was in need of equalization. It sat floating for several days while I was waiting for a good time to run an equalize (these are in my office, so I have to consider weather conditions when I ventilate them. To my shock, all 12 cells were between 1.255 and 1.265 after sitting at float for so long.

The initial float current was around 0.01C (9A), and it dropped to <1A over a couple days. It's currently sitting at 0.6A floating a 936Ah bank. All the SG are spot on.

Even after the extended float, I would still run an equalize per Trojan's instructions and the added guidelines in this thread just as a "reset button" precaution ensuring you've burned off any potential sulfation that occurred during the sit.
 
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