Installing Solar Storage Yourself? These 7 Mistakes Might Burn Your Equipment

Mistake 1: No DC Isolator – Or Using a Cheap AC Switch

What happens?

No DC switch between the solar panels and the inverter. Or between the battery and the inverter. Or someone uses a cheap AC switch they had lying around.

When you need to repair the system, you can't disconnect safely. Worse, DC current doesn't have a zero crossing point. It creates arcs much worse than AC. A cheap switch will keep arcing when you try to turn it off. The contacts burn. The arc continues. Fire starts.

How to do it right:

Key point: Buy a DC-rated switch. AC switches cannot do the job. They look similar. The internal arc suppression is completely different.

Mistake 2: Undersized Cables – The Hidden Fire Risk

What happens?

To save money, someone uses thinner cables than required. Or they only have thin cable on hand, so they use it.

Thin cable has higher resistance. Current flows through it. It heats up. More load means more heat. Insulation melts. Positive and negative wires short out. Sparks. Fire.

This is not an exaggeration. We saw a real case: a customer used 4mm² cable for a 2000W inverter. After 30 minutes at full load, the cable turned into a heating wire and melted every wire around it.

How to do it right:

Three more rules:

Longer distance needs thicker cable (add 20% more cross-section per extra meter)

Use copper wire if possible. If you use aluminum, go 30% thicker

Tighten all connections. A loose connection creates high heat

Mistake 3: Reversing Polarity – Instant Destruction

What happens?

Red goes to black. Black goes to red.

One second. Or just a touch.

Some inverters have reverse polarity protection. But if yours doesn't, or the diode can't handle the surge, here's what happens: capacitors explode. MOSFETs short out. The circuit board burns. No repair possible.

How to do it right:

Use a multimeter to check battery polarity before connecting (red probe to positive, black to negative – you should see positive voltage)

Use different colors for wires: red for positive, black for negative. Don't use the same color.

If possible, use different connector types for positive and negative terminals

Connect the battery positive last. Have a fire extinguisher nearby just in case

A note on protection: Our CHNB-M, X, C, and E series all have reverse polarity protection. Even if you reverse the connection, the internal circuit won't burn. But the protection has limits – leaving it reversed for a long time can still cause damage. Always connect correctly.

Mistake 4: No Grounding – Or Wrong Grounding

What happens?

No ground connection at all. Or the ground wire goes to a water pipe, heating pipe, or lightning rod. Or someone uses the battery negative as ground.

No grounding means: if the equipment leaks current, the metal case can become live. You touch it – you get shocked. Worse, when lightning strikes or a grid surge happens, the energy has nowhere to go. It all goes into your equipment. Everything burns.

How to do it right:

Key points:

Use a dedicated copper ground bus bar

Ground wire size: at least 50% of the largest current-carrying wire

Ground resistance: less than 4Ω (an electrician can measure this)

Do not connect the inverter's AC output neutral directly to battery negative

Mistake 5: Installing in an Enclosed Space – Summer Turns It Into an Oven

What happens?

You put the inverter and battery inside a small enclosed cabinet. You close the door. Summer comes.

The inverter makes heat when running. The battery makes heat when charging. Enclosed space. No ventilation. Temperature climbs to 60°C, 70°C, 80°C.

Then:

Electrolytic capacitors lose half their life for every 10°C rise

Power transistors lose efficiency and may thermally break down

LFP batteries are safer than NMC, but high temperatures still age them faster

How to do it right:

Leave at least 15cm of space around the inverter for airflow

Add forced cooling fans to the cabinet (use a temperature switch to control them)

Do not put the inverter directly above the battery (hot air rises – the battery gets even hotter)

If installing outdoors, pick a shaded, dry, well-ventilated spot

Temperature reference:

Best operating temperature: 20°C – 30°C

Allowable range for our products: -25°C – +70°C

Long-term exposure above 50°C: lifespan drops significantly

Above 70°C: over-temperature protection may shut down the unit

Mistake 6: Incorrect Battery Series/Parallel Wiring – Imbalance Leads to Early Failure

What happens?

Someone buys two 12V batteries. They connect them in series to make 24V. But the batteries are different ages, different brands, different capacities.

Or they connect three batteries in parallel, but the wiring is wrong. The middle battery gets the most current. It fails first.

With series connections: when charging, the smaller battery fills up first, then gets overcharged. When discharging, the smaller battery empties first, then gets over-discharged. After a few cycles, that "weakest link" battery is dead.

With parallel connections: if the wiring is not symmetrical, the battery closest to the inverter carries more current. The others sit back and do less work.

How to do it right:

Series (to increase voltage):

Use the same brand, same model, same batch of batteries

Fully charge each battery individually before connecting in series

Add a battery balancer or use a BMS with active balancing

Parallel (to increase capacity):

Same brand, same model, same batch required

Use diagonal wiring (see diagram below)

Do not parallel more than 4 batteries (current sharing becomes difficult)