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First PB Deep-Cycle pack advice appreciated.
#11
If you are going to connect lead acid batteries in parallel, make sure to wire them correctly. Otherwise you will have unbalanced changing/discharging and the batteries will degrade much more quickly.

https://www.impactbattery.com/blog/tutor...-parallel/
OffGridInTheCity and Crimp Daddy like this post
Modular PowerShelf using 3D printed packs.  40kWh and growing.
https://secondlifestorage.com/showthread.php?tid=6458
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#12
(09-29-2019, 12:55 AM)ajw22 Wrote: If you are going to connect lead acid batteries in parallel, make sure to wire them correctly.  Otherwise you will have unbalanced changing/discharging and the batteries will degrade much more quickly.

https://www.impactbattery.com/blog/tutor...-parallel/

Thanks, that is extremely helpful
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[Image: avatar.jpg]Tony
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#13
Unfortunately it looks like all the 12x RBC43 5.5AH (12v) have all been discharged (they have never been used as far as I know) to 6-7V each.
Guessing these are useless now, or can they be revived (or even worth doing)?

Plan B is some 36v 30AH LifePo4 I've been offered.
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[Image: avatar.jpg]Tony
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#14
You can try reviving them... hopefully they are not too sulfated internally.  Its a pretty easy process... just hook it up to low current charger, trickle charger, bench top DC power supply, or RC charger (my recommendation) on a low settings.

I recommend doing a capacity test like we typically do on 18650 cells.  That would give you a much better idea of the general health, along with an internal resistance measurement.

I do this a lot with recovered APC / UPS batteries... sometimes you get lucky, sometimes you get crap.

Unfortunately all of the ones I got below, were VERY low capacity even though the held a reasonable surface charge voltage. Pretty disappointing.  Point being, the voltage doesn't always tell the whole story.





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#15
Cheers!
That's somewhat reassuring as these had been sitting unused in my server room well over a year in their box (some tit ordered the wrong ones for a client) before making their way home with me.

Will stick them on my ISDT q6+ on PB trickle mode tonight, then run a cap test.
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[Image: avatar.jpg]Tony
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#16
I have 8 brand new 5Ah SLA batteries that recently made its way home with me… I ordered them to refurbish an APC unit only to find out the unit itself was dead. Too lazy to return it, so now I have 40Ah worth of SLA I need to use somehow.

As much as I love lithium, these types of batteries really are great, easy, and safe. Great for small projects without the complexity of BMS modules and stuff. Plus I already have a bunch of really high quality lead MPPT solar charge controllers.

You already have a capable charger so just use that for testing.
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#17
(10-04-2019, 03:34 PM)Crimp Daddy Wrote: You can try reviving them... hopefully they are not too sulfated internally.  Its a pretty easy process... just hook it up to low current charger, trickle charger, bench top DC power supply, or RC charger (my recommendation) on a low settings.

I recommend doing a capacity test like we typically do on 18650 cells.  That would give you a much better idea of the general health, along with an internal resistance measurement.

I do this a lot with recovered APC / UPS batteries... sometimes you get lucky, sometimes you get crap.

Unfortunately all of the ones I got below, were VERY low capacity even though the held a reasonable surface charge voltage. Pretty disappointing.  Point being, the voltage doesn't always tell the whole story.

Have you ever had to top them up with distilled water?
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[Image: avatar.jpg]Tony
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#18
(10-04-2019, 05:51 PM)amerrigan Wrote:
(10-04-2019, 03:34 PM)Crimp Daddy Wrote: You can try reviving them... hopefully they are not too sulfated internally.  Its a pretty easy process... just hook it up to low current charger, trickle charger, bench top DC power supply, or RC charger (my recommendation) on a low settings.

I recommend doing a capacity test like we typically do on 18650 cells.  That would give you a much better idea of the general health, along with an internal resistance measurement.

I do this a lot with recovered APC / UPS batteries... sometimes you get lucky, sometimes you get crap.

Unfortunately all of the ones I got below, were VERY low capacity even though the held a reasonable surface charge voltage. Pretty disappointing.  Point being, the voltage doesn't always tell the whole story.

Have you ever had to top them up with distilled water?

No, I haven't bothered to go out of my way to refurbish in that manner. 

At this point batteries are more of an unnecessary addiction.  I have more than I need or could care to use so I don’t really go out of my way to save them. 

The lead acid stuff is only because I come across a lot of server room UPS units and I just have a habit of wanting to take it home to see if they are any good.  More often than not I take them to recycling center for the scrap lead value if they are end of life.
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#19
(10-04-2019, 05:49 PM)Crimp Daddy Wrote: I have 8 brand new 5Ah SLA batteries that recently made its way home with me… I ordered them to refurbish an APC unit only to find out the unit itself was dead.  Too lazy to return it, so now I have 40Ah worth of SLA I need to use somehow.

As much as I love lithium, these types of batteries really are great, easy, and safe.  Great for small projects without the complexity of BMS modules and stuff.  Plus I already have a bunch of really high quality lead MPPT solar charge controllers.

You already have a capable charger so just use that for testing.

I'm a electronics engineer (in a past life) and IT manager nowadays; also a keen "drone" racer so I've got plenty of bits and bobs that suit this "new hobby" (/addiction) in the shed. Honestly see this getting out of hand at some point. 

The Q6+ is a good bit of kit in the field, I reckon I could probably use that to charge the PB bank straight from the solar panel better than the crappy PWM I got currently. It's trying to bring the battery up to min voltage @0.1A (set to 1A) in pulse mode and seems to be holding at 6.8V (up from 5.2v on this cell)
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[Image: avatar.jpg]Tony
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#20
I’ve been into this stuff for about 15 years by now… it all started with RC cars, helicopters, and flashlights which started my battery addiction.

Let me know when it get out of hand…  I think I hit that limit when I bought 33kwh worth of EV modules. 

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