Deye Solar + Storage Procurement Checklist: Inverter, LiFePO4 Battery, and EV Charger Buying Notes (2025)

This is not a system-design tutorial. I'm the person who orders the equipment. I've managed purchasing for a 35-person solar and electrical contractor since 2021—roughly $1.2M to $1.4M a year in equipment, spread across nine distributor accounts. I report to operations and finance, so my version of getting it right is simple: the right product lands on the right job site with paperwork that passes an audit.

Before we start, the odd search phrase. How many comets are in our solar system? According to NASA's Solar System Exploration pages, the current known count is more than 3,800, and the total keeps changing. If that's the reason you landed here, that's your answer. If you're actually comparing Deye inverters and batteries, keep reading.

This checklist has five steps. It isn't exhaustive. My experience is based on mid-size residential and light commercial projects in North America and Europe—not utility-scale work. If you're buying for a 100 MW site, you need a different person with a different spreadsheet.

Step 1: Run a power inverter calculator before you request quotes

I keep a power inverter calculator in my process for one reason: it catches load mismatches before the purchase order goes out. I'm not an engineer, and I've learned not to trust eyeball math.

In 2024, a project manager told me a site needed a 6 kW inverter because that's what the preliminary design said. The project also had a 7.2 kW EV charger and an old air conditioner. I ran the numbers through the calculator again—the charger alone was over half the inverter's continuous output. We revised the design before the PO, which saved us a restocking fee and a conversation I didn't want to have with my operations manager.

Why does this matter? Because a power inverter calculator doesn't care about brand names. It only cares whether the output number is big enough for the continuous load, with headroom for surges. The room for error is fairly small once a PO is signed. Write down the continuous watts, surge watts, input voltage, and battery voltage if there's a battery. Include that summary in the RFQ so every distributor quotes on the same scope.

Step 2: Treat the Deye 6kw inverter price as a range, not a number

The Deye 6kw inverter price is not a single number. In January 2025, I saw distributor quotes from about $1,250 to $1,800 for a 6 kW hybrid inverter from Deye. That's a snapshot, not a promise (as of February 2025, at least). That range did not always include the extras (e.g., a CT clamp, a Wi-Fi dongle, or a smart meter). Add those items and the spread gets wider.

The difference between the cheapest and most expensive quote often comes down to the suffix after the model number. A grid-tied-only version can be cheaper than a hybrid with a backup port. Don't let a salesman call both 'a 6kW inverter.' The part number is the product; the category name is marketing.

My rule: ask for the exact part number, the included accessories, the MPPT input count, and whether the unit has a backup or off-grid port. If the quote doesn't show those details, it's not a quote yet—it's a teaser.

Step 3: Order the Deye LiFePO4 battery on the same PO as the inverter

If you're buying a Deye hybrid inverter, put the Deye LiFePO4 battery on the same purchase order. Third-party batteries can work, but they bring a compatibility conversation that takes time and sometimes money.

A Deye LiFePO4 battery and a Deye inverter are designed to communicate over CAN. That doesn't guarantee plug-and-play, but it's a lot closer than mixing brands with different BMS protocols. With a third-party battery, the installer has to confirm voltage range, charge/discharge limits, and the correct battery communication board. That extra hour on site is exactly the kind of thing the installation crew will remember.

Never expected the battery to be the reason a permit stalled. Turns out the building department wanted the battery's UL certificate and nameplate data, not another inverter spec sheet. So include battery certificates, SDS, and installation manual in your first RFQ.

Also, write 'Deye LiFePO4 battery' on the PO, not 'Deye battery.' If it doesn't say lithium iron phosphate, ask why.

Step 4: Verify the charger circuit before you pick a Level 2 charger

EV chargers are the part of Deye's product line that still catches people off guard. If a customer already has a DeWalt Level 2 charger, they might expect it to work alongside the new solar system. Fine. The question isn't the brand—it's the circuit and the load.

A DeWalt Level 2 charger has the same electrical need as Deye's own EV charger: a dedicated circuit sized for its continuous current, plus a load calculation that includes the inverter and battery charging. Don't assume the solar system can just run it without checking the numbers.

The biggest overlooked item here is monitoring. If the Deye smart meter, inverter, and charger are part of one ecosystem, features like export limiting and time-of-use control are easier to set up. But 'easier' doesn't mean automatic. Confirm who creates the monitoring account, how the customer gets access, and who transfers it after commissioning.

Step 5: Buy the paperwork, not just the hardware

The most frustrating part of buying Deye gear is not the gear. It's documentation. You'd think a model number on a PO would be enough, but three distributors can interpret the same suffix three ways.

I now put a documents requirement in every RFQ. At minimum: wiring diagram, installation manual, battery UN38.3 and SDS, and the compliance certificates for the destination market. For U.S. jobs, check NEC 2023 grounding and rapid shutdown requirements—Article 690 is a good place to start. For Canada, look for CSA marking. For the EU, ask for the CE declaration and relevant grid code. Verify current regulations with the official sources; a distributor's 'should be fine' is not a compliance opinion.

In Q3 2024, a vendor sent a Deye inverter with CE documents but not the UL listing we needed for a U.S. permit. We caught it because the certificate list was on the PO, but the project still slipped nine days. That was a hidden cost of roughly $2,400 in reshipping and engineering time. The lowest quote on the inverter was not the lowest cost by the time the project landed.

And check the invoice format before you order. A distributor who can't issue a clean invoice is a finance problem waiting to happen. In 2023, a vendor with handwritten-style receipts cost us about $2,100 in rejected expenses. I now verify invoicing capability before any order over $1,000.

The part of the checklist I keep changing

The fundamentals haven't changed: size the inverter to the load, pair the battery with compatible BMS, and keep compliance paperwork in the same folder as the PO. What has changed is execution. In 2021, we usually ordered the inverter from one brand, batteries from another, and EV charging from a third. Today, one Deye account can cover more of that list, which makes procurement simpler—if you verify compatibility instead of assuming the brand family makes it automatic.

Real talk: this checklist isn't complicated. It just forces conversations that are easy to skip. If you ask me, the more complete the RFQ, the fewer problems I need to solve after the truck arrives.

My experience is based on about 200 purchase orders over five years, mostly mid-size residential and light commercial. If your projects are different, your mileage will vary. Use this as a starting point, not gospel.

And if you came here for the astronomy question: you now have a short answer, a Deye checklist, and another reason not to trust a fixed number without a timestamp. How many comets are in our solar system? More than 3,800 known, still changing. Kind of like inverter pricing.