SAJ review

SAJ - Battery Reviews


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Finn's SAJ Batteries Review & Verdict

Finn Peacock has been a Chartered Electrical Engineer since 1998, and is ex-CSIRO

Last time I looked at a wholesale price list these batteries were by far the cheapest per kWh on the list.

I want to see more batteries on more homes. So I hope they are excellent. But the low, low price makes me nervous.  Time will tell.

About SAJ

SAJ is a Chinese manufacturer of solar inverters and home battery systems with products aimed at the budget end of the market. They also make smart pumps and control systems for pumps and electric motors, but I’m guessing you’re not here to read about them.

As of Nov 2023, the SAJ Australian website lists 4 home battery systems. All have stackable modular battery units that give flexibility with the amount of storage installed.

SAJ battery range

Below I’ll give some brief information on the company and then tell you what I know about their home batteries and warranties.

SAJ Company Background

SAJ was founded in 2005. Its full name is Guangzhou Sanjing Electric Co. LTD. I have no idea how they managed to shorten that to SAJ, but I’m glad they did.

The company is located in Guangzhou City. While my grandparents referred to this city as Canton, if you want Chinese people to know what you’re talking about, try not to call it that. SAJ’s precise location is Guangzhou Science City, which sounds like something out of a comic book. It’s actually an industrial area for tech-focused companies. Whether or not there are superheroes defending it, I have no idea.

Australian Office

SAJ has a Melbourne office. Its precise address is:

  • 1 Precision Lane, Notting Hill, VIC 3168

An Australian office is an advantage as it means there’s someone in the country you can contact if one of their products has a problem and the installer is no longer around. It also makes it harder for a company to abandon the Australian market if they run into problems.

HS2 “All-In-One” Modular Home Batteries

Two of the four battery systems SAJ offers on its Australian website are all-in-one systems. This means they have their own built-in hybrid solar inverter that can accept DC power from solar panels and change it into the AC power homes use, making a separate solar inverter unnecessary. It also controls the charging and discharging of the battery modules.

All-in-one units are usually used when new a solar system and a battery are both installed at the same time. But they can be used to replace an existing solar inverter.

SAJ calls their all-in-one batteries “HS2”. There is a single-phase and three-phase version:

  • HS2-3~6K-S2: Single-phase all-in-one
  • HS2-5~10K-T2: 3-phase all-in-one

Most homes only have single-phase power and so can’t use the 3-phase version. Those with 3-phase homes can choose between single-phase or 3-phase battery systems.

The HS2 all-in-one systems use SAJ’s B2 series of higher-voltage battery modules. Each provides 4.5kWh of useable energy storage when new. The single-phase HS2 can have up to 4 of these modules for a maximum of 18kWh of usable storage, while the 3-phase one can have up to 5 modules for a maximum of 22.5 kilowatt-hours (kWh) of usable storage.

B2 Higher Voltage Modular Batteries

Rather than use an SAJ all-in-one H2S battery system, SAJ’s B2 series batteries can be paired with a hybrid inverter. To avoid compatibility issues, this will normally be an SAJ hybrid inverter. But it’s also possible to use a battery inverter, such as one from Selectronic. These batteries can be used with single-phase or 3-phase inverters.

When their higher voltage modules are used, SAJ refers to the battery as B2-(5.0-25.0)-HV1. This can have from 1 to 5 battery modules stacked on top of each other, giving from 4.5 to 22.5kWh of storage. As with the HS2 all-in-one batteries, their continuous power output is limited to either 68% of the usable storage capacity or what the inverter can provide.

B2 Low Voltage Modular Batteries

SAJ’s lower voltage battery modules can also be used. When this is done, SAJ refers to the battery as B2-5.0-LV1. These modules have 4.6kWh of useable storage each and up to 8 of them can be stacked for a maximum of 36.8kWh of usable storage. Their continuous power output in kW is up to 108% of their usable storage capacity, but they will also be limited by the capacity of the hybrid or battery inverter they are connected to.

As it’s a low-voltage battery it will normally need to be located within 1.5m of its hybrid inverter due to the thick and heavy cables that are required.

Installation Location

SAJ batteries are suited for outdoor installation. However, they have to be kept out of direct sunlight and rain. Also, if climate change suddenly moves in a completely unexpected direction, you’ll have to stop snow accumulating on them.

SAJ battery installation locations


The SAJ battery warranty is for 10 years or until they have discharged 3,060kWh of stored electrical energy per kWh of usable storage. Whichever comes first.

This means if you had a 3-module SAJ battery with 13.5kWh of usable storage the warranty would either end after 10 years or when it had discharged over 41,310kWh. (13.5kWh x 3,060 = 41,310kWh.)

If the battery’s average daily discharge is equal to its usable storage capacity when new, the warranty will end just before 8.4 years have passed. This means it’s not a great warranty for people who expect to use their batteries at a high capacity factor.

The warranty promises the battery will maintain a minimum of 60% of its original capacity, for as long as the warranty lasts.

To receive the full warranty the battery must be registered and connected to the internet. Otherwise, its maximum warranty will only be 5.5 years.

10-Year Inverter Warranties

In Australia, SAJ give their solar inverters 10-year warranties. This means that if you get a HS2 all-in-one system you won’t need to worry about the inverter warranty coming to an end before the battery warranty does.

Making A Warranty Claim

If your SAJ battery develops a problem you should first contact the installer you bought it from. If they’re no longer around, then you can contact SAJ directly. Their Australian office number is:

  • Australia office hotline: 1800 888 725

You can also email them:

Not Much Info Available

At this time (Nov 2023) SAJ batteries are not widely installed in Australia. Because we currently don’t have much information on them we don’t include them on our Battery Comparison Table. We definitely don’t have enough information to include them among the home batteries we recommend in our Solar Batteries 101 Guide. If you do get a SAJ battery installed and would like to leave a review, we’ll appreciate the additional information.

SAJ has no solar batteries in our database

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