Redarc SBi12 on 2018 Prado

[t303 Senior Member Find all posts View Profile Close t303]

GBS 12V 100ah.
https://gbsbattery.en.made-in-china....4-Battery.html

Google can do the rest if anyone is interested. I am happy to consider any expert observations that can be made after you look at the datasheets, Be advised however, I don't want to know how it works at the molecular level, I just want to run the fridge in the back of my Prado and caravan. Pretty much all I need to know are the charge and discharge limits so I can stay in the middle of the envelope, there is NO WAY I will ever approach even 0.5C, charge over 14V, nor operate my Prado in any extremes of climate, so all the rest of the technical BS is not a concern to me.

Opinions are like ar$eholes; everyone has one, and most of them stink . In the end people can sell/buy/use what they like. In MY opinion and limited experience nothing so far beats Li overall except on price (and that's arguable).
I have no barrow to push, I don't profit from anyone buying ANY sort of battery. I am just a talented amateur, but somehow I seem to be able to make this tricky Li stuff work satisfactorily for me without $1K+ worth of BMS/DC-DC charger/etc. I am yet to be convinced that there is a better option that satisfies MY requirements (and, as you are aware, that of many others on various forums). All I want is the lightest battery with the most capacity/kg that will charge from the OEM electrical system, and with a little bit of care and attention Li will do that without me replicating the control room at Liddell.
Cheers
Steve

[drivesafe Senior Member Find all posts View Profile Close drivesafe]

GBS 12V 100ah.

https://gbsbattery.en.made-in-china....4-Battery.html




Google can do the rest if anyone is interested. I am happy to consider any expert observations that can be made after you look at the datasheets

WHAT DATASHEETS? Can you please post up a link to these DATASHEETS.

How do you conclude that 20% is "as low as you can take a Li battery"? The first two cycles I took out of my new Li pack were 100 and 101Ah (according to the PL20 reg, which is all I have) and I terminated the 17A load at 11.4V. That's 100% of claimed capacity and still above the 11.2V min specified by GBS for a 12V pack (2.5V single cell). It may well decline with age, but so will the LC.

Sorry, but IMHO there is not a LA battery that is "equivalent" to a LiFeP04 in what I consider important: weight, cycles and lower charge voltage requirements (therefore needing less power consuming "gear" to boost V); so being less than half the price seems to be the only benefit. Perhaps on a $ per cycle value they might arguably be similar given the Li has been tested (albeit by the manufacturer, as I assume this LC has) to 2000 cycles (100% DOD).

It appears to this mug punter that their only equivalence is (maybe) price/cycle?

t303, the little info available states that the 2000 cycles were to 80% DOD ( or 20% SoC as I stated ) not 2000 cycles to 100% DOD as you have claimed.




Again, the little info I have been able to get suggested these batteries need a BMS, and 14.2v to be able to fully charge them.




For the benefit of those who have not worked with LiFeP04 Batteries, and I have been testing them for more than 5 years now, unlike any lead acid battery where you can use a lower voltage than maximum, to fully charge them, it just takes a lot longer to fully charge with lower voltages.




With LiFeP04 batteries, if you do not apply the recommended charge voltage, and use a lower voltage, ( t303’s case, a MUCH lower voltage ) a LiFeP04 battery will only charge to a specific capacity, base on what ever the charge voltage is.




For instance, if a given brand of LiFeP04 battery states you need 14.2v and you only charge it with a maximum of 13.6v, the battery may never get over 80 SoC.




So t303 would you please correct my info if it is wrong, again by posting a like to the “DATASHEETS” for your battery?

[t303 Senior Member Find all posts View Profile Close t303]

Drivesafe,
I did my own investigation, then I bought two of these batteries AND USED THEM IN A PRACTICAL APPLICATION. I relied on the manufacturers data when I researched as, I note, have you. I guess eventually we will see which manufacturer tells the biggest lies.
I have NO interest in getting into a technical pi$$ing contest with you, I USE my battery in a working setup, and for my purposes (and you know there are many others like me on the caravanner forum) these LiFeP04 batteries WORK in basic, practical configurations without a zillion bucks worth of gear to charge and "protect" them. Hi/low voltage protection is all I need for MY application. There is no need for me to know how my computer works at the microcode level and how fast the FSB is; I just need to be able to turn it on and have it run reliably so that I can read crap on internet forums. My batteries are used in a similar PRACTICAL way.
My PRACTICAL requirements are these, and only these:
low weight
high capacity for that weight
low voltage charging
longevity (acceptable price/cycle)
avoid the need to weigh myself down with extra electronics (space, avoid losses, maintain reliability and "fixability". I hate warm beer)

I want them to run my fridge and a few other 12V items, that's all. If someone wants to build/sell people a medical grade, mission critical all singing dancing piece of kit, then they can do their R&D, ISO9000, and whatever else they need and I'll be suitably impressed.. Me, I just want to run the fridge in my car and caravan. In my experience, Li fulfills my requirements, and it is my OPINION that it may well suit others at a similar cost to buying the latest LA technology and adding the charging equipment necessary.
Please stop trying to build straw men, I am not interested in debating the theory and specs, I simply wish to pass on my experience charging and using Lithium batteries in a working RV configuration.
I understand that you are testing LC tech, I will be interested in your results.

If anyone wants some info on the practical use of LiFeP04 they can PM me
cheers
Steve

[t303 Senior Member Find all posts View Profile Close t303]

Apologies Drivesafe, I rudely neglected to answer your questions

t303, the little info available states that the 2000 cycles were to 80% DOD ( or 20% SoC as I stated ) not 2000 cycles to 100% DOD as you have claimed.

From a vendor's website : Some other LiFePO4 manufacturers make grand claims about cell cycle life that are simply untrue.
GBS cells are measured to 2000+ cycles at 100% Depth of Discharge (their use of boldface)
I cannot verify this claim, and I imagine you are in the same boat with LC
;
Again, the little info I have been able to get suggested these batteries need a BMS, and 14.2v to be able to fully charge them.

Not stated in my post was the fact that the two discharge tests of 100 and 101Ah were from 13.8V , possibly slightly lower for the second, I can't recall. The necessity for a BMS is widely spruiked by the vendors and manufacturers of said BMS's. Sensible, experienced end users, myself included, beg to differ.

For the benefit of those who have not worked with LiFeP04 Batteries, and I have been testing them for more than 5 years now, unlike any lead acid battery where you can use a lower voltage than maximum, to fully charge them, it just takes a lot longer to fully charge with lower voltages.

In power supply mode my 35A charge will charge at 35A (or it's internally limited rate) until it reaches the set voltage (13.8V) at which time it tapers. That's the beauty of Li: negligible taper of the charging. In fact, the best charger is a large bench power supply: no "intelligence" trying shape to charge. The battery will accept charge at the capacity of the charger in my experience, if you want a higher end voltage then obviously it will take longer! Many sources seem to regard the battery as effectively "charged" circa 13.6V. From my tests it appears that 13.8V is all that is necessary to make spec. Experience from others suggests that anything above is usable, but negligible. I have yet to verify, but have no reason, nor mobile method of doing so. My vehicle will only charge to about 13.4-13.6V, so I consider my pack "safe" from overcharging even in the unlikely event that it becomes unbalanced (hasn't yet)

With LiFeP04 batteries, if you do not apply the recommended charge voltage, and use a lower voltage, ( t303’s case, a MUCH lower voltage ) a LiFeP04 battery will only charge to a specific capacity, base on what ever the charge voltage is.

Mine seem to roughly meet spec at 13.8V, 100 and 101AH discharge according to my PL20, Perhaps I should set the charger to GEL or AGM and see how much is available from 14.4V.


For instance, if a given brand of LiFeP04 battery states you need 14.2v and you only charge it with a maximum of 13.6v, the battery may never get over 80 SoC.

Depends on the "knee" in the charging graph. I would have to look it up, but the last few tenths of a volt adds not much charge for the risk of damaging an unbalanced pack (as does deep discharge). Risk vs Return is not acceptable to me, I would rather buy another 100AH pack and parallel for capacity.

I hope the above answers your questions.
cheers
Steve

[drivesafe Senior Member Find all posts View Profile Close drivesafe]

Well t303, l guess it’s a waste of time asking yet again for a link to the battery’s specs.

Simply parroting some “VENDOR’S” advertising is not what was asked for.

Have a nice day t303.

[t303 Senior Member Find all posts View Profile Close t303]

Well t303, l guess it’s a waste of time asking yet again for a link to the battery’s specs.

Simply parroting some “VENDOR’S” advertising is not what was asked for.

Have a nice day t303.

Sorry Drivesafe,
I have looked and can't find one on the web, and I frankly don't need one. I have installed, and used, the packs and have determined them fit for my purpose. One has been in use for more than three years.
Unfortunately it appears that my experience using the technology is not valid in your view, so be it......
cheers
Steve