[RE-wrenches] LFP storage

[Steven Lawrence]

Do you store your batteries at room temperature?  What degradation do you
see when it's not at room temperature?  On large BESS containers, I get a
long term storage document from the OEM and the only major item in there is
ambient temperature.  You get increasing degradation with colder
temperatures.  It becomes a major discussion point on projects as we have
to get temp generators to power the HVAC, or schedule BESS deliveries
towards the end of the project, or store the BESS containers in a climate
controlled environment.


>
> Date: Sat, 3 Jan 2026 09:15:19 -0700
> From: Starlight <larry at starlightsolar.com>
> To: RE-wrenches <re-wrenches at lists.re-wrenches.org>
> Subject: Re: [RE-wrenches] LFP storage
> Message-ID: <E86894B3-BA28-4BBA-9D87-01B57BE9AACD at starlightsolar.com>
> Content-Type: text/plain; charset="utf-8"
>
> Hello Jay,
>
> We have been in the Li-ion battery business for 13 years. I can share our
> experience with our LiFeBlue brand and also with GBS cells.
>
> In our shop we have LFP test cells that have been sitting disconnected for
> over 7 years. Each time we test these, the capacity loss is negligible.
> Some are stored at 50%, some at 100% SoC. There are other factors I wont
> get into but the longevity is remarkable.
>
> Our recommend storage method for periods over 30 days is to establish
> about a 50% SoC (about 13.2V) and disconnect the battery. Make sure it?s
> full disconnected as a small load can drain over 4kWh per month. When ready
> for use, recharge fully for cell balancing and to calibrate the internal
> SoC meter.
>
> Some customers use batteries in a UPS configuration for radio systems
> backup. The voltage is fixed at 14.2V. The cells are only discharged during
> a power outage. Some of these systems are over a decade old.
>
> Our RV and Marine batteries are often left on float charge of 13.8V while
> being stored for many months. The downside of this is if the charger
> malfunctions you might over-discharge the battery. This could be difficult
> to recover if left in a full discharge state.
>
> If you?re going to disconnect the battery, be sure to check it
> occasionally as some batteries have a high self discharge rate. Our brand
> has a hibernate mode after 15 days of non use. Current drops to 5uA.
>
> Let me know if I covered it all.
>
> Thank you,
>
> Larry Crutcher
> Starlight Power Systems
>
>
>
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