New home battery from SMA

Slowly but surely, home batteries are starting to enter more and more of our homes. Although for most people there is still little economic benefit to be gained from these battery packs, we notice that interest among our customers is gradually increasing. This is partly due to the intended phasing out of the net-metering scheme from 2025, but the increasing popularity of 'dynamic' energy contracts also plays a role. In addition, there is also a group of people who buy a home battery to protect themselves against possible power failures on the public grid.

Until now, Zonnefabriek mainly installed home batteries from the Chinese brand BYD, which are compatible with SMA inverters. But recently SMA also started offering its own batteries, sold under the name “SMA Home Storage. So what could be the benefit of this for our customers?

Safety first

The SMA Home Storage system consists of modular blocks with a usable storage capacity of 3.28 kWh (kilowatt-hours) each. The batteries are currently only compatible with SMA's Sunny TriPower Smart Energy (STPSE) hybrid inverters; a minimum of 2 and a maximum of 5 of these blocks can be connected to the STPSE. The available storage capacity thus ranges from 6.56 to a maximum of 16.4 kWh. This is sufficient capacity for the vast majority of solar panel owners: most households have a daily power consumption of about 10 to 15 kWh, and it doesn't make much sense to store much more power than you can consume in a day.

What is essential for the home battery is safety. After all, you store a considerable amount of energy in your home, and you need to be sure that such a system will not spontaneously catch fire, because then the stored energy could continue to fuel the fire quite a bit. We all know the stories of cell phones and laptops whose batteries suddenly get hot and start smoldering; the damage to a relatively small battery may be manageable, but for large systems it can have catastrophic consequences.

Since home batteries are usually placed inside homes, it is very important to take the utmost care to ensure their safety; by the way, this applies equally to electric cars, which often have even larger batteries. And also consider e-bikes, which are often charged in the garage: there have been many situations where the batteries of cheap and poorly manufactured e-bikes have caught fire.

Fortunately, it is quite possible to make safe home battery systems. The prerequisite is that the manufacturer's quality control is at a high level, and that the communication between the various components (inverter, battery management system and individual battery modules) is perfect. With the combination of SMA and BYD, we are most confident of this, and perhaps even more so with a combination of SMA inverter with SMA battery.

No cobalt

The technology used for the SMA batteries is lithium iron phosphate (LiFePO4). This technology is seen as the safest option and, unlike Li-NMC technology, contains no cobalt (cobalt is known to often come from less well-regulated mines in the Congo). By the way, BYD batteries use the same technology. (So what is in the SMA batteries? You can find a comprehensive list of the materials here - see page 6)

However, there are also differences between BYD and SMA: BYD batteries are very conveniently stackable. Each tower is about 58.5 cm wide and 30 cm deep. SMA batteries are usually placed against a wall and are 61 cm wide and 21.5 cm deep. BYD batteries should always be placed inside a home, while the SMA batteries can in principle be placed outside, if there is no room for them inside.

Comprehensive warranty

In terms of warranty, SMA's “performance” warranty is a lot better than BYD's: the usable capacity of the batteries decreases with time, but SMA still guarantees 60% of the original capacity 12 years after installation, or after 8,000 “cycles” (charging and discharging). With BYD, that only runs to 10 years and about 3500 cycles (compare that to the battery of an iPhone!). In contrast, the length of the product warranty is the same for both systems (10 years).

BYD's advantage is that (much) larger amounts of battery capacity can be connected to the inverter: A single tower of batteries can store up to 22.1 kWh, and up to 3 towers can be placed in parallel, or more than 66 kWh! Dt will, of course, be a very large investment.

What again weighs in SMA's favor is that with the combination of STPSE and Home Storage you only have to deal with one (German) party should there ever be technical problems or questions about warranty; with the combination SMA and BYD you always have to deal with two parties, one in Germany and one in China. That does not have to be a problem but it is good to realize that.

All in all, we think the new SMA Home Storage batteries could be an interesting product for many customers. You can download the datasheet of these new batteries here, as well as the extended warranty conditions. The batteries can be ordered immediately: become interested? Then contact us for a quotation.