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Post by prizfindr on Aug 21, 2019 6:09:04 GMT
An acquaintance of mine emailed Renogy and asked what the SOC of a Renogy Lithium battery should be at 30% and 50%. The answer that came back was "about 11.4v and 12v" respectively. Pardon my French, but WTF? That's worse than a lead acid battery, and it doesn't at all match (to my eye) the SOC discharge rate on the Spec sheet. Of course, this was music to the ears of some Battle Born owners on the forum I was on, Renogy only produces a discharge curve, and not a chart (like Battle Born), so it's difficult to do an apples to apples comparison.
But seriously, is Renogy Customer Service actually telling people that their lithium battery's are at 12v, at a 50% SOC, and 11.4v at 30% SOC? That would have been a huge negative if I had known that prior to purchasing.
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Post by tattoo on Aug 21, 2019 12:15:48 GMT
An acquaintance of mine emailed Renogy and asked what the SOC of a Renogy Lithium battery should be at 30% and 50%. The answer that came back was "about 11.4v and 12v" respectively. Pardon my French, but WTF? That's worse than a lead acid battery, and it doesn't at all match (to my eye) the SOC discharge rate on the Spec sheet. Of course, this was music to the ears of some Battle Born owners on the forum I was on, Renogy only produces a discharge curve, and not a chart (like Battle Born), so it's difficult to do an apples to apples comparison. But seriously, is Renogy Customer Service actually telling people that their lithium battery's are at 12v, at a 50% SOC, and 11.4v at 30% SOC? That would have been a huge negative if I had known that prior to purchasing. SOC means nothing..... Now 12v and 11.4v does..... But if SOC did mean something how much voltage would you expect a battery that was allowed to run down to 30% have? 12.5?
The lesson here is not let your battery get that low......
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Post by tattoo on Aug 21, 2019 12:19:08 GMT
Pardon my French, but WTF? That's worse than a lead acid battery That's the same as the charts for flooded that I've seen............
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raydas
Solar Devotee
Posts: 166
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Post by raydas on Aug 21, 2019 12:19:17 GMT
yep, do not let the battery run down.
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Post by prizfindr on Aug 21, 2019 12:51:53 GMT
Pardon my French, but WTF? That's worse than a lead acid battery That's the same as the charts for flooded that I've seen............ So I should be happy to have paid a bucket load of money for a battery, that performs just like a lead acid, when there are other lithium battery's on the market that are performing at 13v @ 30% remaining capacity?
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Post by prizfindr on Aug 21, 2019 12:53:52 GMT
yep, do not let the battery run down. If I wanted to be charging the battery all the time, I would have stuck with a lead acid. The performance noted in my OP is really crappy performance (if true), as compared to other leading lithium batteries.
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Post by bupkis on Aug 21, 2019 13:03:09 GMT
Hi prizfindr, so what resting voltage does your renogy Li measure as any know SoC? I've seen the discharge curve and IIRC the discharge voltage was well above that of what you were told. www.renogy.com/content/files/Specifications/BATT-LFP-12-100.pdfSo if at 0.2C discharge and 50% SoC the voltage is ~13v then one knows at rest it will be higher than ~13v. I do understand bad info from this forum and tech support but if you have the battery then you can measure it yourself.
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Post by tattoo on Aug 21, 2019 14:10:59 GMT
So I should be happy to have paid a bucket load of money for a battery, that performs just like a lead acid, when there are other lithium battery's on the market that are performing at 13v @ 30% remaining capacity? That's your problem what battery you choose to buy....
Like I said % means NOTHING what the V is that's all that matters.......
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Post by tattoo on Aug 21, 2019 14:12:51 GMT
If I wanted to be charging the battery all the time, I would have stuck with a lead acid. That's what solar does............ It charges the battery ALL the time......... No matter what kind of battery you have....
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raydas
Solar Devotee
Posts: 166
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Post by raydas on Aug 21, 2019 14:25:41 GMT
The Rover MPPT CC, does have a float state. But, when I was looking at the collected data, from the 'Solar Station Monitor' program, I never saw it go into an idle state while the solar panels are active. Now I need some clarification, as to how the float state works, on the Rover MPPT CC. Maybe the data collect will reveal something useful.
Personally I am not sold, yet, on having any kind of lithium battery, for a solar system.
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Post by bupkis on Aug 21, 2019 15:28:09 GMT
The Rover MPPT CC, does have a float state. But, when I was looking at the collected data, from the 'Solar Station Monitor' program, I never saw it go into an idle state while the solar panels are active. Now I need some clarification, as to how the float state works, on the Rover MPPT CC. Maybe the data collect will reveal something useful. Personally I am not sold, yet, on having any kind of lithium battery, for a solar system. See PM for message about float.
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Post by prizfindr on Aug 21, 2019 16:57:21 GMT
If I wanted to be charging the battery all the time, I would have stuck with a lead acid. That's what solar does............ It charges the battery ALL the time......... No matter what kind of battery you have.... That's great. It still doesn't address the question: Are Renogy Lithium batteries *really* only as effective as a lead acid, and if so - why are their competitors achieving far superior results?
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Post by bupkis on Aug 21, 2019 17:16:16 GMT
That's what solar does............ It charges the battery ALL the time......... No matter what kind of battery you have.... That's great. It still doesn't address the question: Are Renogy Lithium batteries *really* only as effective as a lead acid, and if so - why are their competitors achieving far superior results? I doubt your assumption but am interested in your results and other data about Li battery effectiveness. My brother recently acquired 4 battle borns and I will be checking on them over the years. He will mistreat them!
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Post by Admin on Aug 22, 2019 17:10:15 GMT
That's what solar does............ It charges the battery ALL the time......... No matter what kind of battery you have.... That's great. It still doesn't address the question: Are Renogy Lithium batteries *really* only as effective as a lead acid, and if so - why are their competitors achieving far superior results? Lithium batteries (LFP specifically) are overall superior to Lead Acid batteries for a couple reasons: LFP have a higher life cycle and performance than its SLA counterpart, they have higher energy density yet much smaller weight and size compared to SLA. Specifically with SOC%, they are not as downward (curved) sloped as SLA, but moreso of a relatively slow decline (line) before downwardly curving. So a perceived full LFP battery SOC% could be anywhere from 13.614.4 -100% (depending on resting battery or active battery, 100%), whereas 10% is moreso near the 12.2V, with 0% being near 11.5V. HOWEVER, this depends on the method of discharge, so it becomes a lot more complicated to define the SOC based on merely voltage because of the drop-off zone. See the chart for reference. So while the voltage might lead you to believe that it is synonymous, the reality is that even if these batteries are drawn to 0%, you're still looking at 2000 cycles, whereas SLA being drawn to 0 would be closer to 500 cycles. Attachments:
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russ
Solar Advocate
Posts: 63
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Post by russ on Aug 22, 2019 17:11:39 GMT
yep, do not let the battery run down. If I wanted to be charging the battery all the time, I would have stuck with a lead acid. The performance noted in my OP is really crappy performance (if true), as compared to other leading lithium batteries. Lithium batterys last longer when kept between 20 and 80% of full charge, so they are very different than lead acid batteries. Also, you don't want to discharge a lead acid deep cycle battery more than 50%. Lithium batteries are fine to discharge to 20%, so you have more usable capacity.
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