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 > LiFePO4 - SOK or Renogy.

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Almot

out there

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Posted: 02/27/21 03:35pm Link  |  Quote  |  Print  |  Notify Moderator

phemens wrote:

He helped me figure out all the correct settings for my MPPTs and charge controller.

Lynac Lithium

As an aside, the storage of LiFePo4 batteries at 50% is meant for long-term storage (i.e. over the winter), not a problem at all if it's a matter of weeks.

I'm curious what he suggested on controller settings. I see manufacturers labeling their controllers "Lithium compatible" while they are just regular 3-stage controllers with Bulk, Absorb and Float, and Absorb is often fixed 60-90 minutes. My impression has been that Lithium cells don't need Absorb for any substantial period of time. Odd controllers like EcoWorthy that switch to Float in a few seconds after hitting Absorb, is what it needs. I think Float won't hurt much, especially if you set it below BMS cut-off, so it would just start Bulk when voltage drops below Absorb.

Yes, 50% SOC is for long term storage. When you're going to use it in a matter of days or in 2 weeks, you can charge it fully. It's a sliding scale, the more paranoid you are about it the better the chances are that it would live up to the promised 3000-4000 cycles.

BFL13

Victoria, BC

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Posted: 02/27/21 06:45pm Link  |  Quote  |  Print  |  Notify Moderator

Almot, if you don't need the high discharge amp advantage, then what advantage(s) over FLA or AGM, does LFP have that you are willing to pay all that extra money for? You got by ok with your existing batteries ISTR.


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3 tons

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Posted: 02/27/21 07:29pm Link  |  Quote  |  Print  |  Notify Moderator

BFL13 wrote:

Almot, if you don't need the high discharge amp advantage, then what advantage(s) over FLA or AGM, does LFP have that you are willing to pay all that extra money for? You got by ok with your existing batteries ISTR.


Though acquisition cost are definitely higher, it’s hard to make a cogent case that over the long haul LFP’s cost more - However, for some of us this presents a new problem of trying to outlive their own dang batteries!!

3 tons

BFL13

Victoria, BC

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Posted: 02/27/21 07:50pm Link  |  Quote  |  Print  |  Notify Moderator

They should give a "senior's discount" on LFPs with the discount being more as age is higher! [emoticon]

3 tons

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Posted: 02/27/21 09:01pm Link  |  Quote  |  Print  |  Notify Moderator

BFL13 wrote:

They should give a "senior's discount" on LFPs with the discount being more as age is higher! [emoticon]


Now that is a great point Sir - especially when you consider at what age one must attain (ugg!) to be able to afford the dang entry fee!! Ain’t it kinda funny how this works out, and unfortunately my only logical heir is challenged when loading flashlight batteries - lol

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Almot

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Posted: 02/28/21 03:15pm Link  |  Quote  |  Print  |  Notify Moderator

BFL13 wrote:

Almot, if you don't need the high discharge amp advantage, then what advantage(s) over FLA or AGM, does LFP have that you are willing to pay all that extra money for?

The advantage in this particular application is being able to charge partially without worries, and pull in all the amps that a very small solar will output since there is no tapering in the last 20% of LFP.
Also, much higher energy density than FLA - charging possibility could be limited by weather and terrain. With Lynaclithium they're marketing 120AH as 100AH, so it's "safe" 100% DOD.
Also, low weight - it will be moved from time to time. 24 lbs is so much better than 67 lbs. I would rather let the battery outlive me than outlive the battery and get another hernia or ruptured spinal disc.

BFL13

Victoria, BC

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Posted: 02/28/21 03:43pm Link  |  Quote  |  Print  |  Notify Moderator

Almot, thanks for your reasoning on that.

pianotuna

Regina, SK, Canada

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Posted: 02/28/21 09:05pm Link  |  Quote  |  Print  |  Notify Moderator

SiO2 work well with partial charging.


Regards, Don
My ride is a 28 foot Class C, 256 watts solar, soon to have SiO2 batteries, 3000 watt Magnum hybrid inverter, Sola Basic Autoformer, Microair Easy Start.

phemens

Montreal, Canada

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Posted: 03/01/21 07:58am Link  |  Quote  |  Print  |  Notify Moderator

Almot wrote:

phemens wrote:

He helped me figure out all the correct settings for my MPPTs and charge controller.

Lynac Lithium

As an aside, the storage of LiFePo4 batteries at 50% is meant for long-term storage (i.e. over the winter), not a problem at all if it's a matter of weeks.

I'm curious what he suggested on controller settings. I see manufacturers labeling their controllers "Lithium compatible" while they are just regular 3-stage controllers with Bulk, Absorb and Float, and Absorb is often fixed 60-90 minutes. My impression has been that Lithium cells don't need Absorb for any substantial period of time. Odd controllers like EcoWorthy that switch to Float in a few seconds after hitting Absorb, is what it needs. I think Float won't hurt much, especially if you set it below BMS cut-off, so it would just start Bulk when voltage drops below Absorb.

Yes, 50% SOC is for long term storage. When you're going to use it in a matter of days or in 2 weeks, you can charge it fully. It's a sliding scale, the more paranoid you are about it the better the chances are that it would live up to the promised 3000-4000 cycles.

In a nutshell, I'm using a 3000w all in one Samlex unit, with Victron MPPTs for the solar. Here are the settings he gave me for the Samlex (settings essentially same for the Victron, but with temp cutoffs):

Battery type= 1 Lithium

Charging profile 3=2Stage Type1

Absorb Exit Amps=0A

Absorb Time=1 min

Floating exit=12.00V

Equalize-4stages 0=No

LV cut off time = 1200 sec

LV detect time=10 sec

Batt low voltage=12.00V

Low volt alarm=11.50 V

Reset Voltage=12.60 V

Batt over volt=14.40 V

Compensate= 4 mV/C/C

Floating voltage=13.00V

Equalize voltage=14.00V

Absorp voltage=14.20V


2012 Dutchman Denali 324LBS behind a 2006 Ford F-250 V10 out of Montreal
1 DW, 1 DD, 1 DS, 2 HD (Hyper Dogs)
1200w solar, 600AH LIFePO4, Yamaha EF2000 gen, Samlex 3000w Inverter

map40

Florida

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Posted: 03/03/21 01:52pm Link  |  Quote  |  Print  |  Notify Moderator

My only concern would be temp protection, but you mentioned that is not an issue. If that is the case, I bought LifePo4 280Amp cells on Wish shipping from US $270. I am sure you can access it from Canada.
There is also cells in Amazon. They are all the same cells you can find in SOK and the other batteries. Throw in a BMS and make your own battery. I am making a 1200 amps temp protected BT conected for under $1500


Alfa SeeYa, 2015 Jayco XL31, 2015 Itasca XL31, 2012 CA 25, 2008 CA 28. RV with most millage: 312K miles on a V10
Life rocks when your home rolls

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