Hello Howie, You should be aware that Discover Li-ion battery does not have adequate protection to prevent damage if charged below freezing. The data sheet (see attachment) shows that you can charge the battery down to -4°F and adds a text warning not to charge below 32°F.
"Care should be taken to ensure that the battery’s temperature is > 0°C (32°F) during charging." Charging any Li battery below freezing will permanently damage the battery and create a future fire hazard. This is no problem if you can insure that the cells always stay above freezing. IMO, it makes no sense why any Li battery manufacturer does not fully protect their battery. (I know of others) It is simple to inhibit charge current based on cell temperature. To me this can create a ticking time bomb. Someone unknowingly charges a frozen battery. The danger shows up later when the separator is penetrated by dendrite growth caused by lithium plating of the anode. This happened when they charged a frozen battery. Dendrite growth can lead to internal shorting which can be a fire hazard. It would be wise to install these in a sealed metal enclosure or provide another method to prevent charge current when below freezing. Larry Crutcher Starlight Solar Power Systems On May 3, 2019, at 12:45 PM, Howie Michaelson <howie.michael...@gmail.com> wrote: Hi Folks, About to spec my first Lithium battery backup job. The client is not a heavy user, but wants things done right more than being totally cost effective. We put in 14kW of net metered solar using SolarEdge and now he wants the backup component. This was significantly oversized for his use, but he wanted to be sure he was putting a bunch more back into the grid than he was using (making up for past profligate power usage). We will be using a dual stacked XW 6848, mostly for enough backfeed capacity (we could wire in a transfer switch and only use 1 XW, but he'd prefer this setup instead). I have narrowed down my choice for batteries to either: (2) Iron Edison 200 amp hour batteries, or (3) Discover AES 130 amp hour batteries Advantages for the AES are that they integrate directly with the Schneider Xanbus network so the Conext battery monitor provides direct insight into the SOC and SOH of the batteries, and they have a slightly higher rated cycle life so higher lifetime energy capacity. Advantages of the IronEdison are they come in a larger amp hour size allowing for only needing 2 vs. 3 batteries, they have an integrated fuse and disconnect, and from my sources are 1/3 less in price. If anyone has any thoughts on any of this, or corrections to my comparison, I'd greatly appreciate it.
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