What is considered "storage"

[TommyDKY]

Read a lot of threads that said to store your lifopo4 battery at 50%-60% SOC. What is considered storage? 1 month of no use but still hooked up in the RV or is it 6+ months unhooked and sitting in your garage?
My LifePo4 batteries will be used as the house batteries on my RV. The RV will sit sometimes 1-2 months with minimal usage and I do turn the disconnect switch on both house and starting batteries to the off position. Do I need to run the lifepo4 batteries down to 50-60% when I do that?

 

[snoobler]

Recommendations vary.

Lishen cells give a 1 month (-30 to 45°C) and 6 month (-30 to 35°C) storage temperature range, and a storage charge of 20-40% or 3.275-3.305V without specifying a duration..

Lishen 272Ah specification sheet

1st 7 pages are chinese. the last 8 pages are english

diysolarforum.com

The charge retention test entails fully charging it and letting it sit for 30 days.

Given that it's pretty easy to discharge the battery, I would opt to shoot for 40-50% SoC anytime I know it's going to be parked for 30 days or more.

 

[OnTheRoadAgain]

Good question at a good time.

The Rebel 100Ah LiFePO4 I received today says to store it at 75% charge....yet, it arrived at 40% SOC.
My Jackery Lithium powered Solar charger says to store at 40%.
40% SOC is where I thought Lithium based batteries stored best.

That baffles me as I have never heard of ANY lithium battery storing better at that high a SOC

 

[GSXR1000]

Read a lot of threads that said to store your lifopo4 battery at 50%-60% SOC. What is considered storage? 1 month of no use but still hooked up in the RV or is it 6+ months unhooked and sitting in your garage?
My LifePo4 batteries will be used as the house batteries on my RV. The RV will sit sometimes 1-2 months with minimal usage and I do turn the disconnect switch on both house and starting batteries to the off position. Do I need to run the lifepo4 batteries down to 50-60% when I do that?

do you have solar? how do you charge the battery's

 

[reg]

The Rebel 100Ah LiFePO4 I received today says to store it at 75% charge....yet, it arrived at 40% SOC.

That's probably because it's apparently illegal to ship a battery that size (Hazardous Goods) at more than 30% capacity. I don't know how much attention vendors pay to this. Looks like your battery was a bit over

 

[reg]

Here's what Lithium Werks says about Valence U1-12RT batteries that are sold and used for commercial purposes, usually for medical purposes.

Standard charge: 14.6V
Float charge (if the battery is unused for a month): 13.8V

I recently acquired one of these batteries. After a full charge, the battery's voltage was 14.05V. After several days in "Park Mode" (see below), it settled to a voltage of 13.37/13.36V.

The screen capture below from the User Manual explains further. Note that this battery has a built-in battery management system and a blinking light-emitting diode. These are the reasons for the self-discharge referred to in the screen capture.

 

[OnTheRoadAgain]

I just can't figure out why Rebel batteries says Storage at 75%

Again, that's the highest recommended Storage voltage for a LiFePO4 I have ever seen.

I'm inclined to store at 40% instead.

 

[TommyDKY]

do you have solar? how do you charge the battery's

I bought 8-271 CATL cells from Michael Caro’s group buy. Trying to top balance the first 4 cells In parallel now. I do have solar on the Rv. So I will be charging from 3 different sources—Alternator, solar w/victron controller, and shore power through the Xantrex sw3012 inverter/charger. I am not a full timer.

 

[GSXR1000]

this is my plan... turn on fridge and switch to use charge profile the day before trip

Thread 'Storage of LIFEPO batteries in my RV' https://diysolarforum.com/threads/storage-of-lifepo-batteries-in-my-rv.21529/

 

[Sadie04074]

I just can't figure out why Rebel batteries says Storage at 75%

Again, that's the highest recommended Storage voltage for a LiFePO4 I have ever seen.

I'm inclined to store at 40% instead.

The CEO of BattleBorn is on video saying that their batteries can be stored ANYWHERE BETWEEN 50% AND UP. He went on to say that the important thing was not to store at less than 50%.

 

[OnTheRoadAgain]

The CEO of BattleBorn is on video saying that their batteries can be stored ANYWHERE BETWEEN 50% AND UP. He went on to say that the important thing was not to store at less than 50%.

Interesting.

Mine arrived at 40% (according to BMS) and 3.300v but it's possible the charge had dropped to that point.

I don't think you can go by voltage at all because the voltage to SOC curve is so flat.

I think I'll raise my storage capacity to 50% until I get more info.
Thinking about it......if 75% really is the ideal storage SOC, that would be better since it would leave your pack in a better SOR.....State of Readiness

 

[Gazoo]

The CEO of BattleBorn is on video saying that their batteries can be stored ANYWHERE BETWEEN 50% AND UP. He went on to say that the important thing was not to store at less than 50%.

BattleBorn uses cylindrical cells. So does Valence. Maybe that's why there is a disparity between the recommendations for cylindrical and prismatic cells, and why it's always best to go by the manufacturer's recommendations.

 

[OnTheRoadAgain]

You're pretty sharp for a "dumb dumb"

 

[Gazoo]

You're pretty sharp for a "dumb dumb"

My knowledge comes from the other people sharing on this forum and the experience I have gained playing with my cells. So I try to pass along what I have learned without being wrong and I have been wrong but I try to avoid that. So I thank the other members and Will for most of what I have learned. And I learn new things every time I visit the forum. I will never claim to be an expert.

 

[Substrate]

Reg got it right about shipping - regulations typically put it at no more than 30% SOC, especially when shipping via aircraft is concerned. The regs don't differentiate between LFP and other lithium types, so this is a blanket percentage.

Geekdom vs real-world:
Sure, 30% is fine, but the RISK of not storing it higher in the real world is for a few reasons:

Parasitic discharge in a real install. Even small amounts can add up over time when you do the math for 24/7 parasitic discharge. In an RV, even a small overlooked ground current (or one that develops behind your back), puts the 30% charge level at risk at going even lower and sitting around at the bms cutoff. Or worse. Generally not healthy to sit down that low.

Not being a suitable amount of storage when you need it most! When you go to rely on it, you may not be in the best of conditions via genny or nice bright sunny days as an emergency resource.

So don't worry about it. 30% is only forced upon us by shipping regulations, and sure those who are trying to get the most out of their RC batteries and have the time and willingness to be married to that percentage will get those extra 20 cycles.