timselectric
If I can do it, you can do it.
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Be patient, it's coming.
50% discharge on AGM batteries - old wife's tail
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OzSolar
Whatever you did, that's what you planned.
Data my friend, data. Without data it's just opinion. You can back up your claims or you can't.
timselectric
If I can do it, you can do it.
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The data doesn't exist, yet.
This is why patients is required.
OzSolar
Whatever you did, that's what you planned.
I've got plenty of patience. The LFP fanboys that are talking about 38 years and 10,000 cycles with no real world data to backup thier claims up are the ones that need that advice. Let's be a bit a more polite if we can't back up our claims.
timselectric
If I can do it, you can do it.
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I believe that 10,000 cycles are highly probable.
But nobody will know, until we get there.
OzSolar
Whatever you did, that's what you planned.
In the meantime please do us all a favor and try not make fun of those that ask questions about LFP vs LA. I'm not talking about just you.
OzSolar
Whatever you did, that's what you planned.
Hedges
I See Electromagnetic Fields!
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Rather, lithium batteries making it to their claimed cycle life (even in controlled conditions) is a rarity.
Are LFP prices artificially high?
Cost is irrelevant to sale price. market value is king. profit drawn from building, marketing, future sale reduction pricing, etc. I would be EXTREMELY surprised if sales were anywhere close to material and labor and manufacturing costs... It's like the cannabis market. It costs MAYBE $50 to...
diysolarforum.com
If they can be bought for similar dollars per kWh capacity, they still seem like a no-brainer. Expected to break even with lead-acid at as little as 20% of cycle life, I thought. But some people's calculations are for lead-acid doing much better than I assumed.
These kinds of patients?
Tomthumb62
Solar Wizard
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That’s disturbing to hear. If I wanted to test my 30A Rover (12V) for self consumption, how would I do that? I mean, what was your method? Thanks.
timselectric
If I can do it, you can do it.
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I don't know that I have ever made fun of someone for asking questions. But I will always confirm that LA is old technology. And I believe that it's a waste of money for a permanent system. They are great for testing and temporary. Because you can get them cheap from a junkyard.
HarryN
Solar Enthusiast
Two methods actually.
I didn't have any experience with the Rovers setup / programming details or how it did battery SOC when I started the project, so I added on the same SOC monitor that I always use, a Bogart Trimetic with a shunt. This is my default monitor method for all projects. It isn't perfect but it is quite good. This provides an independent method of measuring what is going on for voltage and current. I use the WiFi module add on to make it easy to look at the info from a tablet pretty far away.
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In addition, I have an Extech 380950 ac / dc clamp meter. I think that it has been replaced by a newer model, but I did a search on line and they are still for sale at much less than I paid in the past.
I actually have 2 clamp meters, one for higher currents and this one for measuring lower currents in small wires such as 10 awg and smaller.
Basically the clamp / circle opens like a pliers and it goes around the wires to take the current measurements, so I did this measurement on the wire that runs from the solar charge controller - through the breaker and then on to the bus bar. If you take the measurements at night, this will tell you how much current is coming out of the batteries to power the solar charge controller.
This works well enough for my use, but there are more precise units out on the market. If you are going to own a solar system, owning a clamp meter is very handy.
It is possible that the one we had was defective and using more power than it was supposed to. Since I didn't buy it, he was communicating with renogy on trying to get a replacement but didn't succeed.
I spoke to them some about how they do the set points and SOC for a 48 volt LiFe system and some of the things that they said could be changed - we were not able to access. For AGMs we could access it, but not for Li batteries.
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There are videos on youtube about how to use a clamp meter and real pros at using them if you dig deeper with a search engine.
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Now that's resolved .... if anyone would like to actually talk about 50% discharge on AGM, I am all ears lol.
What about calendar aging? What about temperature? 6000 cycles is quoted at 25degC. We are in the Tropics with batteries constantly around 30degC. Poor for lifePO4 cycles but better for calender aging. Who knows what life we will get.
Lots of people on boats get 8 years out of 6v Trojan T105s. A friend has 6v batteries installed on his house in Antigua for the last 12 years. They are off grid. They are in a high ambient condition but are still going strong.
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Q-Dog
¯\_(ツ)_/¯
I am dissappointed in this thread. I was expecting to see an old married woman with a tail.
littleharbor2
Solar Addict
You had me there for a second. Had to go to the opening of the thread. Tail? Time to call in the grammar cops.
That can be arranged , for the right price
Zwy
Emperor Of Solar
Like I said, I do a full cycle every 4 to 5 days. Using the 3500 cycle life span that was stated, that comes to 38 years without calendar aging.
If the batteries last 10,000 cycles, I'm pretty certain it won't matter to me or you.
It isn't about being a fanboy, it's about basic math and even the minimum cycle life span that is data from EV's.
Zwy
Emperor Of Solar
I have 8 225Ah 6V lead acid deep cycles, I know what I'm talking about. The only reason I haven't moved to lithium to replace these is 6 T105's were free and there is some life left.
all this talk about 'cycles', but what does that really mean?
is it simply whenever the battery gets discharged/recharged? Is there a time interval?
