2Big2B
Free Wheeler
Will Prowse needs to do a formal retraction to his previous endorsements!
(or maybe he has but I missed that?)
Last edited:
SAMLEX PST-600-24 DC-AC INVERTER PURE SINE WAVE 24VDC IN 120VAC OUT 600 WATT...
- Thread starter 2Big2B
- Start date
(or maybe he has but I missed that?)
Brett V
Mad Scientist
Back to your original dilemma, cooking. This isn’t advice, just a statement of what I’d do. Get a small butane camping burner and hide it on the top shelf of a closet. If the power is out and I needed to heat something up to eat, you get your ass I’ll be discreetly using it with the door locked and window blinds closed.
2Big2B
Free Wheeler
Thank you!
Actually I picked up on your rather cute footnote, and hence my pun in reply about "crossing my legs" which was to imply a dead short across two legs of a ciruit.... I had included the basic SOC curve chart along the way earlier in conversation, learned from a deep dive into all of that when building and balancing my own DIY project battery packs a couple of years ago. Basic training for any real dialogue here...
But actually I am still a little mystified about why the BMS is inappropriate for serial connections. Maybe it was common back then? Just like Icom vs Kenwood, Nikon vs. Canon, Apple vs Microsoft... I guess they all have their reasons buried in history.
But limiting the bms like that seems pretty stupid. Who's idea was it to dismiss that half of the potential commercial applications that way for the sake of a few cents of production costs? Did someone in corporate fall asleep in Marketing 101 ? Maybe the design of that bms was to fullfill some government bidding contract requirement that bled into the adoption of that spec into their basic market limitation? Or maybe I am just naieve that it was a rational decision to allow the competition like Power Queen to have such a marketing advantage.
And here I was operating on the assumption that Renogy was king of the hill based upon Will's enthusiasm on his videos about them 4 years ago - an eternity in this market space. Are they publically traded, or are they free to make unfettered blunders like that? There was probably some earlier corporate politics involved. I have an insight about such things because in the late 80's I was spearheading the establishment of the fledgling Canon Printer Division, as lead product / sales marketing and development engineer giving technical sales seminars to potential major distributors throughout the country, flying 5 days a week, two cities a day as we embraced the US market' to make our own foothold. I was a real road warrior back then - when I wasn't running Comdex trade shows or back in HQ working with third party developers gaining software compatibility and establishing our marketing presence. Long story, a lifetime ago...
Here's an aside though... When you look at your driver's license you will see a DMV color photo of you. I was involved with putting it there. An early part of my career was working "Third Party Developer Relations", and was once part of my title. Some where the big league fish like Microsoft, Word Perfect, Adobe, and then the lesser mainstream. Without printer software drivers right out of the box, nobody would buy our printers no matter what magic was under the hood. Every hardware and software manufacturer was intensely scrambling to establish themselves. I had some real amusing independent guys calling me with pitches for our development support for helping them invent and sell their better mousetrap. I had all kinds of weird stuff to have to deal with.
So I got a call from a Doug someone, another self proclaimed President and CEO of a sole proprietorship. What he was asking for was some free donation current and prototype color ink printers for his use in developing software to; aquire an image, process its printing on paper tape, in a world dominated by dot matrix printers. He was in the stage of being able to print on cash register paper receipt tape. He was trying to take it to the next step using our new fangled Bubble Jet printers. State of the art in 1987. Brilliant idea. He also needed our proprietary language programming manual for writing code for our new, not yet on the market product. Big ask. Now I tag "ISV loaner program engineer" to my latest ever changing business card. So, I let Corporate Legal prepare a standard Non-Disclosure Agreement for Doug to sign and I tracked down the proprietary jinglish programming manuals and other cryptic documentation, and together we were able to make enough sense of it he that he went on his way.
About a year later I was working Fall COMDEX ('88 I guess). The Consumer Electronics Dealers Exposition was one of the major marketing seasonal events held in major cities including; New York, Boston, Chicago, Atlanta, Los Angeles, and in this case Las Vegas. It was a corporate duty that I worked booth in all of them; standing in leather soled Florsheim wingtips on a thinly carpeted cold polished concrete floor, keeping and protecting our supply of handout Sales Literature, paper and printer supplies, in 12 hour shifts, weary and thanking god for having had the wisdom to not have gotten hammered at any of the many opening private invite only parties the in the casinos the night before. I learned after doing that once. There is nothing more miserable than trying to pretend being the Corporate image in front of a few thousand people milling through the hundreds of booths with a thousand opportunities to make business contacts.
So I am standing there at about 9:30 or so I guess, first day of the show, Monday. I was still feeling refreshed the brisk walk from my hotel from the to the main Convention Hall. It was a brisk 3 block walk a couple of hours ago, the start of my shift. It also was on about my 3rd cup of coffee, having stopped into the conveniece shop for my walking cup to go. I was in a hurry to get past a gal buying a case of codoms. I guess that is just the 7:30 early Monday morning crush in that neighborhood. Buying buisiness supplies at a quick stop a 7:30 in the morning dressed in some dingy yet colorful wrinkled short dress, slippers, hair looking slept in, her blush past bloom, looking like what the cat dragged in. Or maybe she was the cat. A tunnel rat, more likely.
So I am standing there, in my sharp suit, Canon insignia pin, smiling at the herd that passes through, passes by, or engages. I am on the lookout for booth bandits. These were a rival company with a booth whose team would raid the competition. I would be confronted by some attendee asking me some convoluted question about out new laser printer, of which I would demonstrate. It was to distract me while his partner would innocently grab all the stackes of our booth handouts, to as sabotage, which was rampant. As was our critical paper supplies. On Wednesday morning opening discovered that our entire supply we'd had shipped in had dissapeared. Catastrophe. I was told about it when I started my shift, upon which I hopped in a cab and hit found a big stationary chain store where I proceed to charge an immediate paper resupply, saving the day while everyone else was too busy playing 'cover your own ass'.
So, I think it was on Tuesday that it was brought to my attention that a Doug someone was looking for me. A couple minutes later this very enthusiastic badged business attendee reached out his hand saying "Mr. Hindley, I want to Thank YOU... You made me a Million Dollars! Skeptical, I smile him and said, in my be at New York attitude So, where's my cut ?!!""
When I got back to base about a week later, my secretary left a package on my desk, addressed to me. I opened it up to find a Thank You card and a big solid 1lb chunk of Ghirardelli Chocolate in appreciation. I shared it with the office. Everyone loves chocolate.
As it turns out, he had pioneered a turnkey hardware/software application that he sold to Costco who used it to make first ever instant photo membership cards at Customer Service. Initially, the first ones where cut and pasted on cardstock with packing tape slapoed on, but soon followed by plastic laminated. I really did make Doug somebody a SOMEBODY millionaire, living the goodlife in San Diego.
The following year, another package with a lb of Ghirardelli Chocolate showed up on my desk. I ate that one.
Anyway,
Will Prowse, you need to rescind your prior endorsement of the Renogy crap that caused me all this trouble!
Everyone, its all Will's fault!
Back to what I was saying...
My technical electrical engineering literacy is a little limited though, inspite of my background. I get the concepts but I am a bit lost in the details at board level. I still don't understand it from examining the spec sheets.
My best guess is that it is a balancing issue caused by the flooding of current from the first battery into the second battery's bms, overwhelming its capacity in a the serial configuration. But that can't be something they couldn't adjust with some sort of buffering from its board level prototype design? Obviously Power Queen and other's were able to do it. So, are the eggheads at Renogy just lazy, or just stupid? I confess my ignorance though and move on. The cultural politics and corporate culture involved in a company like Canon - owned by Japanese but managed by corrupt Americans in the US market was bizzare enough to for me. I outlived my usefulness in pioneering the invention of Canon Printer Division. Canon Corporate took it from there. So, they offered me a transfer to Palo Alto with my now Japanese boss to spearhead an R&D subsiary. I took the new adventure which brought me into the silicon valley, one big nerdfest, and a great time and place to discover 2m, 440, 6m, and exceptional repeater coverage. Electronic surpus salvage everywhere; Fry's, HRO, and the ham flea market and field days. It was a great time for a ham. Days long gone JoeHam.
So, in Conclusion, I am done with any further interest in Renogy products though. They are also yesterday's news ...
(thank you very much)
Last edited:
2Big2B
Free Wheeler
No dilemma.
Will talks of being homeless living out of van.
Me, I was homeless too once, living in the cabin of my 26' fixerup sailboat throughout one Virginia Beach winter. My point being, We have sure come a long way from that.
I have discovered the joy of Poverty, having lost everything to medical bills and burial expense due to my late wife's long battle with bone cancer. It has been its own journey that is behind me.
I am creative.
Now I live comfortbly with all the creature comforts of home, a monthly social security check that pays the rent, Social Services and Senior Services take care of the rest. I get generous food stamps (oh SNAP...). I wear my disability as a banner and shield, as a weapon that I can use if I have to. Self assertion.
And ... I have Meals on Wheels 3 days a week.
Life is good.
Last edited:
Quattrohead
Solar Wizard
Keep kickin arse man 
2Big2B
Free Wheeler
Can you elaborate on this please!
The "legs" of the SOC are exactly the same, no? If so, how'd they manage to "screw up a wet dream" ?
Else I must be operating under a false assumption.
My assumption, is that Prismstic and 18650 Lithium Ion both have identical SOC parameters. But perhaps because of some density difference related to packaging it creates a difference in some inductive capacitance or something.
Huh, what does that even mean? I am making this b.s. up as I go!
Is that it sorta' ?
I refer to the comment:
"At 29.2 V that is 3.65 V per cell. A bit high for my taste. Read some of the millions of posts on proper charge Voltage per cell and draw your own conclusions."
But 14.6v for a12v 4s pack, and 3.65 V per cell, are the "100% Charging Voltages" for both package type, ... no?
- is that my problem ? A false assumption?
Resting 100% SOC is 3.4v per cell. Never above, and usually less, settling to about 3.35 - ish in my experience.
Per the Renogy Spec sheet on the battery charge cuttoff voltage is @14.6, +/- .2v, and low Cuttoff is greater or equal to @10v.
Hmm... that can't be right ... You would kill the battery below nominal voltage =12.8v. ! 12.8/4= 3.2v per cell.
Why would the bms allow the nominal thre we hold??? A different chemestry with a different SOC with 18650 cells?
If so, I am not aware of that...
(I must have snoozed in that class too).
zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz
Can you help me with this?
Last edited:
14.6 (3.65) is a bit high for my taste as well. You can do the math for a 16s and I wouldn’t be a fan either.
3.2V is not terribly low but there’s not a ton of energy left below there.
Let me offer some references to chew through and make your own decisions.
First:
www.solacity.com
Longer, but worth it IMHO :
Both are older references but the facts haven’t changed.
Also, for LiFePO4 prismatic, cylindrical or pouch form factor doesn’t matter to me.
3.2V is not terribly low but there’s not a ton of energy left below there.
Let me offer some references to chew through and make your own decisions.
First:
How to Find Happiness With LiFePO4 (Lithium-Ion) Batteries – Solacity
By: Rob Beckers You have just sold your first-born into slavery, remortgaged the house, and bought yourself a lithium-ion battery! Now you want to know how to take care of your precious new purchase: How to best charge lithium-iron batteries, how to discharge them, and how to get the maximum...
www.solacity.com
Longer, but worth it IMHO :
DIY LiFePO4 Batteries On Boats - Marine How To
DIY LiFePo4 On Boats Last edit;3/26/23:The base of this article was written a number of years ago (2010) but this does not mean the information here is outdated. We have been keeping it updated and have added to it when ever we had the time. This article deals
marinehowto.com
Both are older references but the facts haven’t changed.
Also, for LiFePO4 prismatic, cylindrical or pouch form factor doesn’t matter to me.
Last edited:
2Big2B
Free Wheeler
14.6 (3.65) is a bit high for my taste as well. You can do the math for a 16s and I wouldn’t be a fan either.
3.2V is not terribly scary.
Let me offer some references to chew through and make your own decisions.
First:
How to Find Happiness With LiFePO4 (Lithium-Ion) Batteries – Solacity
By: Rob Beckers You have just sold your first-born into slavery, remortgaged the house, and bought yourself a lithium-ion battery! Now you want to know how to take care of your precious new purchase: How to best charge lithium-iron batteries, how to discharge them, and how to get the maximum...
Longer, but worth it IMHO :
DIY LiFePO4 Batteries On Boats - Marine How To
DIY LiFePo4 On Boats Last edit;3/26/23:The base of this article was written a number of years ago (2010) but this does not mean the information here is outdated. We have been keeping it updated and have added to it when ever we had the time. This article dealsmarinehowto.com
Both are older but the facts haven’t changed.
Also, for LiFePO4 prismatic, cylindrical or pouch form factor doesn’t matter to me.
If it isn't form factor, can you point out to me where the relevant discepenies are between these batteries and standard Lifepo4 SOC?
I still don't get why you can not put some (all?) Renogy 12v batteries in series, but up to 8 can be in a parallel chain?
It's probably a case of the forest vs the trees miopia I am suffering from. It is probably right in front of, an unnoticed sleeping viper that would like to bite me...
2Big2B
Free Wheeler
Thank you for that Joe.14.6 (3.65) is a bit high for my taste as well. You can do the math for a 16s and I wouldn’t be a fan either.
3.2V is not terribly low but there’s not a ton of energy left below there.
Let me offer some references to chew through and make your own decisions.
First:
How to Find Happiness With LiFePO4 (Lithium-Ion) Batteries – Solacity
By: Rob Beckers You have just sold your first-born into slavery, remortgaged the house, and bought yourself a lithium-ion battery! Now you want to know how to take care of your precious new purchase: How to best charge lithium-iron batteries, how to discharge them, and how to get the maximum...
Longer, but worth it IMHO :
DIY LiFePO4 Batteries On Boats - Marine How To
DIY LiFePo4 On Boats Last edit;3/26/23:The base of this article was written a number of years ago (2010) but this does not mean the information here is outdated. We have been keeping it updated and have added to it when ever we had the time. This article dealsmarinehowto.com
Both are older references but the facts haven’t changed.
Also, for LiFePO4 prismatic, cylindrical or pouch form factor doesn’t matter to me.
This being my first experience with packaged stand alone lifepo4 consumer batteries, I was unaware.
Per your " How to Find Happiness With LiFePO4 (Lithium-Ion) Batteries" article, for the sake of anyone else following ths thread:
There is a potential issue when multiple lithium-ion batteries are connected in series. For example, two 12 Volt 100 Ah batteries, each with their own build-in BMS, connected in series to make 24 Volt 100 Ah. Now assume one of those two batteries is near-empty, the other pretty full, and you put a load on the batteries, to discharge them. The near-empty battery will reach the point where the BMS decides “enough is enough” first and it will switch off that battery, in effect disconnecting your entire battery bank, even though the other battery is still full.
The same potential for trouble exists when charging both batteries at the same time with a 24 Volt charging source. The fuller of the two batteries will fill up first, raising the charging Voltage over that battery, until reaching the point where the BMS once again intervenes to protect the battery and switches the full battery off. When the BMS switches off, your entire battery bank “goes away”. If both started off uneven, then the other battery may well be nowhere near full yet, and this will not resolve over time or multiple charge cycles either.
The moral of this story is that you should understand the dynamics of connecting multiple lithium-ion batteries in series. They do not quite behave like lead-acid batteries! Lead-acid batteries will self-balance when they are charged, all attaining a similar state-of-charge in the end. Lithium-ion batteries due to each having their own independent BMS do not! From experience we know that by-and-large series connected batteries, each with their own BMS, can work fine. It would be a good idea though to make sure both are “in sync” every now and then, by charging them individually with a 12 Volt charger, until both are known to be fully charged, so they start off with the same state-of-charge.
Because it is important to understand this, we will come back to it and other BMS-related peculiarities in more detail further below.
Other BMS-Induced Peculiarities & Problems
The BMS (Battery Management System) that is build into the batteries functions as a simple on-off switch, switching the batteries off when Voltage, current, or temperature parameters get to the edge of what is safe. Contrary to what many think, the BMS does not change the charge or discharge current, it really is just an on-off switch; if you have a charging source that can push hundreds of Amps into the battery the BMS will not prevent you from doing this, but it will sense the large current, and switch the battery off when the upper safe limit is reached!
So there it is. And it is probably why Power Queen's Chat Support was suggesting I should probably use a balancer in my pair of Power Queen 12.8v Group 24 'Trailer Batteries' It is probably in their in house support knowledge base that she parroted to me for a potential problem that is probably never going to happen with their batteries, but is a potential remedy for pairing battery'siIn a chain with crappy bms boards.
Now I get it.
- and that begs the question: Can a battery charge balancer solve a scenario like I am in with the Renogy crap?
I expect the ebay seller to probably cancel the sale and issue a refund anyway though, making this whole exercize academic...
I wonder if I should retitle and move this thread to a better category. This be an education to other grasshoppers like me.
"Grass-hoppa... if you can take this pebble from my hand..."
2Big2B
Free Wheeler
Epilogue:
I just found this this thread from cyclingccrn, May 21. 2022.
Noob question: 12V 100aH batts in series?
https://diysolarforum.com/threads/noob-question-12v-100ah-batts-in-series.40367/
It is the same discussion from another member who was facing the same issue of discovering his new pair of Renology 12v lifepo4 batteries he bought couldn't be connected in serial for a 24v system he had planned. He came to the same conclusion to either try to return them, or else change the planned configuration. Same crap, different year.
I am dumfounded that Renogy, and others like them with crummy BMS boards are still in business.
zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz
Epilogue #2 :
EQ24-2 (2x12V=24V) Battery equalizer Watts247
Upon further examination I found this battery equilizer that is specificaly designed a $28 (plus shipping) solution to the Renogy parallel only problem.
Having searched ebay, Alibaba and Amazon, none of them convincingly specify use with with lifepo4 batteries. Maybe they all do the same thing, and maybe you can get something like it on Amazon to save shipping with Prime membership, but I am not convinced that they really work with lifepo4. This one does, and it seems to be only on this guy's site. (I tried price shopping it).
Specifically made for a simple 12v x2 = 24v serial configuration
It works with lifepo4 !
---> https://www.youtube.com/watch?v=ot7Nr12tYxw <---
Has anyone here tried one of these ?
If so, please chime in if you have any experience with this product !
I bet this would work with crappy bms controlled Renogy lifepo4 "Serial Only" batteries!
A simple remedy. What do you think ?
I think I need one of these...
I just found this this thread from cyclingccrn, May 21. 2022.
Noob question: 12V 100aH batts in series?
https://diysolarforum.com/threads/noob-question-12v-100ah-batts-in-series.40367/
It is the same discussion from another member who was facing the same issue of discovering his new pair of Renology 12v lifepo4 batteries he bought couldn't be connected in serial for a 24v system he had planned. He came to the same conclusion to either try to return them, or else change the planned configuration. Same crap, different year.
I am dumfounded that Renogy, and others like them with crummy BMS boards are still in business.
zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz
Epilogue #2 :
EQ24-2 (2x12V=24V) Battery equalizer Watts247
Upon further examination I found this battery equilizer that is specificaly designed a $28 (plus shipping) solution to the Renogy parallel only problem.
Having searched ebay, Alibaba and Amazon, none of them convincingly specify use with with lifepo4 batteries. Maybe they all do the same thing, and maybe you can get something like it on Amazon to save shipping with Prime membership, but I am not convinced that they really work with lifepo4. This one does, and it seems to be only on this guy's site. (I tried price shopping it).
Specifically made for a simple 12v x2 = 24v serial configuration
It works with lifepo4 !
---> https://www.youtube.com/watch?v=ot7Nr12tYxw <---
Has anyone here tried one of these ?
If so, please chime in if you have any experience with this product !
I bet this would work with crappy bms controlled Renogy lifepo4 "Serial Only" batteries!
A simple remedy. What do you think ?
I think I need one of these...
Last edited:
2Big2B
Free Wheeler
I am building a solar battery charger for my wheelchair that I can hang in my patio. I am probably the first to try that!!
2Big2B
Free Wheeler
You are right. I happen to have a single burner propane camping stove that would work in stealth...
Similar threads
