Pull the spec sheet on any battery in our catalog and you will find the same four letters. LFP.
Every one of them. The racks, the wall mounts, indoor and outdoor. That is worth understanding before somebody offers you a cheaper pack with "lithium-ion" on the box.
Lithium-ion is a family, not a chemistry
Lithium-ion describes how a battery works, not what it is made of. Lithium moves from one electrode to the other when you charge, and back the other way when you discharge. A lot of different chemistries do that, and they do not all behave the same.
LFP is one of them. Lithium iron phosphate, written LiFePO4 on a spec sheet.
So a listing that says "lithium-ion battery" and stops there has not told you which one you are buying. The four letters are the part that matters, and a seller who has them will print them.
What we are not going to tell you
Plenty of articles will rank the chemistries against each other. This one will not tell you how our batteries stack up against the pack in somebody else's wall unit, because we have not tested that pack and we do not hold its paperwork. What follows is what our gear is rated to do, off its own spec sheets.
Here is the shape of the thing we are talking about. The 16kWh Indoor WallMount stands 34.1 inches tall, 18.1 inches wide, and 9.6 inches deep, and it either bolts to a wall or stands on the floor. Furniture, not a gadget. Plan the space before you plan the wiring.
What the sheets say
Cycles first. The EG4 LifePower4 and LL-S racks are rated at 7000 cycles to 80% depth of discharge. Run one down and fill it back up every single day and you reach that mark in about 19 years. Both carry a 10-year limited warranty.
Temperature next, and read these as the manufacturer's limits rather than a forecast. The 16kWh WallMount is rated to discharge from -4°F to 131°F and to charge between 32°F and 122°F. Charging has the narrower window, which is the part that surprises people.
That is why the WallMount carries a 448W heater inside the case. It runs off the internal battery temperature, not the air in the room: heat on at 32°F, heat off at 37°F. The pack looks after its own cells in the cold without you doing anything.
On safety, the WallMount has internal fire arrestors and reinforced cell enclosures. The 16kWh Indoor WallMount is listed to UL 9540 as an energy storage system and UL 1973 at the battery level, with cell-level UL 9540A fire testing on file. Those are certificates we hold for that model. No battery holding real energy is risk-free, and anyone who tells you otherwise is selling.
The number on the box is not the number you get
Worth knowing while you compare. The 16kWh WallMount is 16kWh nominal and 12.86kWh usable at the recommended 80% depth of discharge. The racks are 5.12kWh nominal apiece.
Nominal is the headline figure. Usable is the one your house actually spends. Size a bank on the wrong one and you come up short on the exact night you needed it.
Four things to read on the cheaper pack
Somebody will offer you a battery for less than ours. Sometimes that is a fine deal. Four things tell you which kind you are looking at.
Read the chemistry, not the marketing. If the listing will not say LiFePO4 or LFP in plain text, ask why.
Read the cycle rating together with the depth of discharge it was measured at. One number without the other means nothing. Half the cycles measured at half the depth is a different battery wearing a similar headline.
Read the warranty, then find out who honors it and where they answer the phone. Ten years is only as good as the company behind it.
Ask for the listings. UL 9540 and UL 1973 are certificates a manufacturer either holds or does not, so ask to see them and judge the answer you get.
Then buy whichever one wins. If that turns out not to be ours, we would rather you knew what you were getting.
Not sure how much battery your house needs? Run your loads through the system builder at apesolar.com, or call the shop and we will work through them with you.
Ready for Anything.