Do Not Buy Vestwood Batteries

I would like to share my experience with Vestwood batteries as a warning to anyone considering purchasing them.

Based on my experience, I would be very cautious about purchasing Vestwood batteries or purchasing in any brand of battery through Rev-Tech / IOT REVOLUTION TECHNOLOGIES or TAG SA / tagsa.co.za or suppliers associated with them.

We purchased Vestwood batteries on the recommendation of our solar installer. For approximately two years, the batteries appeared to work as expected. After that, we started experiencing a serious issue. When the batteries dropped to around 45% or lower, running a basic household appliance such as a kettle would cause the batteries to drop by 8% to 13% within a few seconds. In some cases, they would even drop below the minimum battery percentage set on the inverter, which was initially set at 35%.

The installer came out several times. The inverter firmware and battery firmware were updated, but the issue was not resolved.

Eventually, in September 2025, the batteries were sent away for assessment. The email correspondence relating to the issue and warranty process has involved both Rev-Tech / IOT REVOLUTION TECHNOLOGIES and TAG SA / tagsa.co.za.

We were without the batteries until November 2025. When they were returned, we were told the BMS had been replaced. Unfortunately, the battery cases were returned with scratches that were not there when the batteries were handed over to the installer.

At first, the batteries seemed to be working again. However, this was during summer, when our batteries generally do not drop below 50%. As soon as March 2026 arrived and the batteries started dropping below that level again, the exact same issue returned.

I reported the issue to the installer in March 2026, but had to keep pushing for months before the batteries were finally taken away again in June 2026.

The batteries are now with the supplier for further testing. Each time, I have been told that nothing appears to be wrong with the batteries. However, this does not match our real-world experience. In my view, a 10kWh battery system should not drop by 8% to 13% within seconds simply because a kettle is switched on.

Based on my experience, these batteries have been unreliable, and the warranty process has been extremely disappointing. In my view, the warranty has felt like an empty promise rather than meaningful support. A warranty that does not result in a proper resolution when the same fault keeps returning amounts to very little in practice.

I would caution anyone considering Vestwood batteries to think very carefully and to make sure they fully understand what support they will actually receive if something goes wrong.

Based on my experience, I would also be very cautious about purchasing any brand of battery supplied or supported through Rev-Tech / IOT REVOLUTION TECHNOLOGIES or TAG SA / tagsa.co.za unless the warranty terms, supplier responsibilities, testing procedures, fault criteria, and replacement conditions are clearly provided in writing before purchase.

In my view, a warranty is only meaningful if the supplier stands behind the product when there is a real-world fault. Otherwise, it is just a piece of paper that gives the customer very little protection when they actually need help.