EG4 WallMount Indoor 280Ah vs 314Ah Indoor: Specifications and What We Have Run

EG4's WallMount Indoor 280Ah and 314Ah Indoor compared on EG4's own documents, with what we ran on the 280Ah. Not a recommendation.

Last reviewed 2026-10-13.

What the manufacturer documents

• EG4's WallMount Indoor 280Ah specification sheet, version 1.1.8, lists 51.2 V, 280 Ah and a total energy capacity of 14.3 kWh at 25 C and 100 percent state of charge. It lists a bulk and absorb charging voltage of 56.0 V (plus or minus 0.8 V) in the BMS column and 56.2 V (plus or minus 0.2 V) in a separate recommended-setting column, with a float of 54 V (plus or minus 0.2 V) and a 20 percent state-of-charge cutoff, both in the recommended-setting column. A footnote says EG4 recommends setting the cutoff no lower than 20 percent to maintain the recommended 80 percent depth of discharge. (eg4electronics.com)
• The 280Ah sheet lists a maximum continuous charge current of 140 A and a maximum continuous discharge current of 140 A, with a further 200 A listed as the maximum continuous discharge for 30 minutes. The recommended charge and discharge settings are listed as 60 to 140 A. (eg4electronics.com)
• The 280Ah sheet lists a charging range of 0 to about 50 C, a discharging range of minus 20 to about 55 C, a storage range of 0 to about 45 C, ingress protection IP20 and an operating altitude below 5000 m. Its heater is listed at 56 V and 224 W, turning on at an internal battery temperature of 0 C or below and off at 5 C or above. (eg4electronics.com)
• The 280Ah sheet lists dimensions of 34.1 by 18.1 by 10.4 in, a weight of 286.6 lbs, more than 8000 cycles at 0.5C and 80 percent depth of discharge, a design life of more than 10 years, UL1973 and UL 9540A under safety certifications, and a lifetime production of 82.6 MWh whose footnote formula assumes 90 percent efficiency. Its cell balancing is listed as a 120 mA passive balance when the cell voltage difference is above 40 mV. (eg4electronics.com)
• The cover page of the 280Ah sheet describes an on-board LCD touch screen with selectable closed-loop communication with EG4, Schneider, Sol-Ark, Victron, Growatt, Megarevo, Luxpower and Deye inverters, dual on-board fire arrestors, an integrated self-heating feature and 600 A internal busbars with 4 positive and 4 negative terminals. (eg4electronics.com)
• EG4's WallMount Indoor 280Ah quick start guide, version 1.4.0, contains the battery's configuration procedures, including how the master battery and inverter protocol are set, and parallel connection examples that depend on the number of batteries and inverters and on the busbars used. We do not reproduce any of it here; read the guide itself. (eg4electronics.com)
• EG4's WallMount 314Ah Indoor specification sheet, version 1.0.4 (model WM-48-314-IN-XX, XX being 00 to 99), lists a nominal energy capacity of 16 kWh and a usable energy of 12.86 kWh at 80 percent depth of discharge (listed as recommended), 51.2 V nominal, 314 Ah, a recommended voltage range of 47.5 to 57.6 V, a charging voltage range of 56 to 57 V and a discharging cut-off voltage of 47.5 V. (eg4electronics.com)
• The 314Ah Indoor sheet lists a maximum continuous and recommended charge current of 157 A and 157 A, and a maximum continuous and recommended discharge current of 200 A and 157 A. It lists a continuous charge and discharge power of 8 and 10.2 kW, a recommended rate of 0.5C, a peak power of 12.8 kW for 3 seconds, a round-trip efficiency of 95 percent, a short circuit current of 1700 A with a 15 ms delay and a 250 A battery breaker. (eg4electronics.com)
• The 314Ah Indoor sheet lists a charge range of 32 to 122 F (0 to 50 C), a discharge range of minus 4 to 131 F (minus 20 to 55 C), storage of minus 4 to 131 F for less than 3 months with 59 to 86 F (15 to 30 C) recommended for longer storage, 5 to 95 percent humidity (non-condensing), natural convection cooling, an altitude below 3000 m and ingress protection IP20. Its heater is listed at 56 V and 448 W, on at 0 C or below and off at 3 C or above. (eg4electronics.com)
• The 314Ah Indoor sheet lists dimensions of 34.1 by 18.1 by 9.6 in, a weight of 293.2 lbs, a cycle life of 10000 cycles to 70 percent end-of-life capacity at 0.5C, 25 C and 80 percent depth of discharge, a design life of 10 years, a warranty of 10 years or 10000 cycles, and a lifetime production of 122.2 MWh whose footnote formula assumes 95 percent efficiency. It lists UL 1973 and UL 9540A as yes, and for UL 9540 refers to EG4's website for supported configurations. (eg4electronics.com)
• The cover page of the 314Ah Indoor sheet describes active balancing (2 to 3 A), automatic configuration that eliminates manual DIP switch setup, a smart BMS that automatically detects and communicates with EG4 inverters, configurable normally-open and normally-closed ports with a 12 V output, and over the air firmware updates through the EG4 battery monitoring app. In its specifications table the sheet lists a maximum of 32 parallel units and a display of LED status indicators. (eg4electronics.com)
• EG4's WallMount 314Ah Indoor user manual, version 1.0.4, says its Auto-ID feature detects the inverter communication protocol and assigns battery IDs without DIP switches, and is available only on EG4 batteries that have no DIP switches. It says that when using the internal busbars, the system supports up to six batteries in parallel, connected to one, two or three FlexBOSS21 inverters (these are configuration examples in the manual), and that variations of up to 10 percent in state of charge between paralleled batteries with their own BMS are normal. The manual also says that, when pairing the battery with an inverter, the load on the master battery must not exceed 600 A because of the internal busbar rating. (eg4electronics.com)
• EG4's application note on paralleling 314Ah batteries to 280Ah batteries, version 1.1, says that adding 314Ah batteries to a 280Ah bank means the ESS is no longer a UL 9540 listed configuration, that the 314Ah battery must be the master because it has no DIP switches, that a custom communication cable is required between the two types, that state of charge can differ by up to 5 percent between them, and that a maximum of eight 314Ah batteries can be paralleled when communicating with 280Ah batteries. The note has further requirements that we do not reproduce. (eg4electronics.com)

What happened to us

• We reviewed a new WallMount Indoor 280Ah battery that we bought. Its on-board screen showed the standby state, the communication protocol the battery was set to, the voltage, a capacity figure and the current, and had a date and time that were close but not set. A password was needed to change the protocol in its settings, and the settings had an English and Spanish language choice and showed the firmware versions. (video)
• On the screen of that unit, just out of the box with the breaker off, the cell voltages were all close to about 3300 mV and the four temperature sensors read about 22 C with a circuit board temperature of 21 C. We did not find a way to show Fahrenheit. (video)
• On the top of the 280Ah unit we saw four connectors for the positive side and four for the negative side, which we said are connected in parallel through a busbar rated up to 600 A, plus a DIP switch, a reset pinhole, CAN and RS485 ports and battery communication ports. The unit has a breaker on its side and a push-button power switch for the BMS and screen, and in the video we said the breaker's enclosure is IP67 rated while the battery as a whole is not. We have no manufacturer document for that breaker enclosure statement, and EG4's sheets list IP20 for the battery. (video)
• In a temporary test that we said we do not recommend, one 280Ah Indoor battery powered a 6000XP at about 91 percent of its load capacity, which fed a Chargeverter charging a second 280Ah Indoor battery. We read the Chargeverter at about 55 V and 92.8 A, the powering battery at about 119.7 A, and the battery being charged at about 92.8 to 92.9 A input. We said we would let it run and come back to it, and that we did not want to charge the second battery all the way. The video does not report how the test ended. (video)
• We unboxed the conduit box made for the 280Ah Indoor and the 6000XP. We said it is metal, that its knockouts are not watertight or airtight and let light through the gaps, and that because the battery mounting plate sits about half an inch to an inch off the wall, there is a gap between the back of the conduit box and the wall. (video)

Specifications side by side

What we did not verify

• This page compares manufacturer documents. The only figures from our own use are the ones under 'What happened to us', and they are all from the 280Ah. We have not run an EG4 314Ah battery and make no claim about how it performs.
• EG4 sells more than one 314Ah battery. We compare the WallMount 314Ah Indoor (model WM-48-314-IN-XX) because it is the indoor counterpart of the 280Ah Indoor and the one EG4 describes with a 16 kWh capacity. EG4 also lists a WallMount 314Ah All Weather battery, which we did not compare.
• The versions cited are 1.1.8 for the 280Ah sheet, 1.0.4 for the 314Ah Indoor sheet, 1.4.0 for the 280Ah quick start guide, 1.0.4 for the 314Ah Indoor user manual and 1.1 for the paralleling note. EG4 changes these documents; the 280Ah sheet's changelog shows that weight, current ratings and temperature ranges were changed in earlier versions.
• Our 280Ah review video was published in May 2024, before the current sheet. In it we said the battery weighs 282 lbs (the current sheet lists 286.6 lbs), that EG4's marketing described a 15 year design lifespan (the current sheet lists a design life of more than 10 years), and that EG4 was still testing for UL 9540A (the current sheet lists UL 9540A). We have not checked which sheet matched our unit.
• The two sheets do not measure everything the same way. Cycle life, lifetime production, charging voltage, storage temperature and discharge current are listed under different conditions, and the table says so. One sheet may list a figure that the other does not; we have not filled gaps with estimates or calculations of our own.
• The load test in the video was a single temporary setup, which we said we do not recommend, using Chargeverter and 6000XP equipment. We did not record the state of charge, the temperature or the firmware versions, and we do not know whether the readings would repeat.
• We have not verified EG4's claims about certifications, cycle life, efficiency or compatibility, and have not seen the certificates or test reports. We make no claim of compatibility beyond what the cited documents state.
• Choosing a battery, sizing a bank, mixing 280Ah and 314Ah batteries, wiring, fusing or protection are for a licensed professional using EG4's current documents.
• The model number, hardware revision and firmware versions of the 280Ah battery we ran were not recorded, and we have not run a 314Ah battery. The battery connector in the load-test video is not named here, and we make no statement about the warranty registration terms, which we have not confirmed with EG4.

Questions and answers

What is the difference in energy between the two?

EG4's sheets list 14.3 kWh total energy for the 280Ah at 25 C and 100 percent state of charge, and 16 kWh nominal energy (12.86 kWh usable at 80 percent depth of discharge) for the 314Ah Indoor.

Do both have a heater and the same IP rating?

Both sheets list an internal heater and ingress protection IP20. The listed heater power is 224 W for the 280Ah and 448 W for the 314Ah Indoor, with different off temperatures.

How is setup different?

EG4's documents describe DIP switch IDs and a protocol chosen on a screen for the 280Ah, and Auto-ID without DIP switches for the 314Ah Indoor. We have only set up the 280Ah.

Can 280Ah and 314Ah batteries be paralleled?

EG4 has an application note on it, version 1.1, with several conditions, including that the combined system is no longer a UL 9540 listed configuration. Read that note and ask EG4 or a licensed professional; we have not tried it.

Which one should I buy?

We do not make that recommendation. Their specifications are listed above, and the right choice depends on your loads and system, which a licensed professional can size.

Sources

• EG4 WallMount Indoor 280Ah specification sheet, version 1.1.8 (EG4)
• EG4 WallMount Indoor 280Ah quick start guide, version 1.4.0 (EG4)
• EG4 WallMount 314Ah Indoor specification sheet, version 1.0.4 (EG4)
• EG4 WallMount 314Ah Indoor user manual, version 1.0.4 (EG4)
• EG4 WallMount 314Ah Indoor quick start guide, version 1.0.6 (EG4)
• EG4 application note, paralleling 314Ah to 280Ah batteries, version 1.1 (EG4)

Videos this comes from

• EG4-WallMount Indoor Battery Review | 48V 280Ah | 14.3kWh | Indoor | Heated UL1973, UL9540A – Our review of the WallMount Indoor 280Ah battery, with a load test
• EG4 48V Indoor 280Ah WallMount Battery Conduit Box Unboxing / Review | 1511094 – Unboxing the conduit box made for the WallMount Indoor 280Ah

Related topics

• EG4 WallMount and Rack Batteries

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