EV Charging Infrastructure Procurement: A 6-Point Checklist Covering CATL Supply, Level 3 Chargers, and Solar Modules

About eight months ago, my boss dropped a folder on my desk labeled "EV infrastructure" and told me to figure it out. We were adding 23 EVs to our fleet, the parking lot had one 240V tap, and management wanted a solar canopy on top of it all. Not because we're climate heroes — because fuel costs were eating the operations budget.

I'm not an engineer. I'm the office administrator who handles procurement for a 300-person logistics company. Roughly $400,000 a year flows through our energy and equipment vendors, and I report to both operations and finance — which means every order gets reviewed twice: once for specs, once for cost. This checklist is for anyone sitting in that same chair.

There are six steps. Step one is the one almost everyone skips.

1. Verify the battery supplier's real production and market position

People assume a big battery brand name is enough. Honestly, it's not. You need to verify two separate things: the manufacturer's actual capacity, and your vendor's actual access to that capacity.

On the manufacturer side, CATL is the dominant player. CATL's share of China's EV battery market in 2024 was roughly 43%, according to the China Automotive Battery Innovation Alliance. SNE Research's global data puts CATL above 37% for the same year. Those numbers matter because market share, in this industry, is a proxy for production capacity, raw material access, and the ability to actually fulfill large orders.

The question I get internally is: "Will prices go down if we wait?" Prices per kWh have been trending down since we started this project in 2022. But supply is the wildcard. On the sodium-ion side, CATL's Naxtra platform is the one to watch for storage buyers. Take this with a grain of salt: public statements and supply-chain reporting suggest CATL Naxtra production volume could land in the 30 to 50 GWh range in 2026. CATL hasn't published a locked-in figure that I've been able to find, so treat any number you see — including mine — as directional, not contractual.

What you should actually do:

• Ask your vendor for the cell supplier's name in writing. If they say "CATL cells inside," ask for the supply agreement or a letter of authorization from CATL.
• Confirm the cell chemistry. LFP handles thermal runaway differently than NMC. For stationary storage, LFP is, in my opinion, the safer bet.
• Check the vendor's order history. We almost signed with a reseller last year who claimed CATL access. They couldn't produce a single delivery record from the previous 12 months. Red flag.

In 2022, I approved a rush order from a new vendor because the quote was $40,000 cheaper than our regular supplier. They couldn't produce certification documents for the battery modules. Finance rejected the expense report, and I ate the cost out of the department budget. Now I verify documentation capability before I even request a price.

2. Understand what "Level 3 EV charger" actually requires

From the outside, it looks like a Level 3 charger is just a bigger, faster Level 2. The reality is a completely different animal. Level 3 charging is DC fast charging, typically 50 kW to 350 kW, and it requires three-phase power, transformer capacity, and permits that Level 2 units don't.

Level 1: 120V AC. Essentially useless for fleet charging.

Level 2: 240V AC, 6 to 19 kW. This is the overnight depot charging sweet spot.

Level 3 (DCFC): 50 to 350 kW DC. For en-route top-ups, not overnight parking.

The counterintuitive part: most fleet depots don't need Level 3 at all. Our fleet EVs sit for 8+ hours overnight. Level 2 units at roughly 11 kW each fully charge most EVs in that window. Level 3 makes sense if the vehicles run multiple shifts, or if the site serves public traffic.

I went back and forth between two 60 kW DC units and one 150 kW unit for about a week. On paper, the single 150 kW unit was the no-brainer: more power, more press coverage, fewer units to maintain. But two 60 kW units meant two vehicles could charge simultaneously, and the queue moved better for our shift pattern. Ultimately, we chose the two 60 kW units. Utilization mattered more than peak speed.

Cost reality: a 150 kW DC fast charger typically runs $50,000 to $120,000 installed, depending on grid upgrades. That's from NREL's 2024 installation cost data. A Level 2 commercial unit is more like $2,000 to $10,000. The bottom line: match the infrastructure to the actual duty cycle, not the brochure.

3. Right-size the inverter: a 1500W inverter is not a 1500V inverter

This one is basically my favorite procurement trap. Search "1500 power inverter" and you'll pull up two completely different products:

1500W inverter: A portable unit converting 12V DC to 110V AC. Enough to run a coffee maker, not a commercial battery rack.

1500V inverter: A large commercial or utility-scale unit rated for 1500V DC input from a solar array and battery bank. Not something you plug into a wall outlet.

People assume they're interchangeable because the number 1500 is the same. The unit of measurement is the deal-breaker. A 1500W portable inverter will not run a commercial battery storage system, and a 1500V inverter is not a portable toy.

When sizing an inverter for a solar + storage + EV charging site, the DC voltage architecture drives the equipment cost. The 1500V DC architecture is the current standard for large commercial installations because it reduces wiring losses and balance-of-system costs. Verify the inverter's DC input rating matches your battery rack and solar array voltage, and check for UL 1741 or IEC 62109 certification before committing.

One thing I learned the expensive way: the inverter's AC output rating determines how many chargers it can feed. An 11 kW Level 2 charger needs an inverter with at least that much headroom. Don't hold me to the exact tolerance, but a buffer of 20% has kept our breakers from tripping at 7 AM when every driver plugs in.

4. Specify solar modules, not "solar panels"

If you ask for "solar panels," you get quotes for "solar panels." If you write "PV modules" and attach a spec sheet, you get something vet-able. The solar module vs panel distinction sounds like grammar, but in procurement it's a real fork in the road. A solar module is the manufactured unit — the specific product with a datasheet, model number, and warranty. "Panel" is the colloquial term, and what one project manager means by "panel" can differ wildly from another's.

On the module datasheet, check three things:

• Power tolerance. A "400W" module that's actually 395W is legal if the datasheet says "+5/-5%". Know what you're paying for.
• Degradation rate. First-year degradation plus the annual linear rate determines 25-year output. A 0.5% annual degradation module is way more valuable than a 1.0% one, even at a higher upfront price.
• Temperature coefficient. Modules lose output as they heat up. In a hot climate, a better coefficient is worth paying for.

The prevention angle: five minutes spent parsing the spec sheet at quote stage beats five days of rework at installation stage. We once approved a module based on an installer's "equivalent to" description, and the delivered unit had a different connector type. The rework cost us a week of construction schedule and a grumpy site manager.

5. Run a complete total-cost-of-ownership number

Upfront purchase price is maybe 60% of the real cost. The rest is hiding in grid connection studies, permit fees, annual maintenance contracts, and insurance requirements.

I'm not 100% sure our first TCO model captured everything, but the line items we track now are: equipment and shipping; site civil work like trenching and conduit; the grid interconnection study and utility upgrade fees; permits and inspections; insurance premium changes; and planned maintenance like charger firmware updates, inverter filter replacement, and module washing. The utility interconnection study alone can eat $5,000 to $15,000 before a single shovel hits the ground.

For reference, utility-scale DC storage systems trended around $150 to $250 per kWh in 2024, based on BloombergNEF data. Pair storage with solar under a 1500V architecture and the economics start to make sense — but only if you model your specific load profile, not the vendor's.

Back in 2021, a small vendor who couldn't provide proper invoicing cost us $2,400 in rejected expenses. Small order, small vendor, big lesson. The same lesson scales up as budgets grow.

6. Verify certifications before the PO, not after delivery

Certification gaps are easier to catch on paper than on a truck. We check for:

• UL 2594 for Level 2 EV chargers; UL 2202 for DC fast chargers.
• UL 1741 or IEC 62109 for inverters.
• IEC 62619 for battery cells and packs.
• National Electrical Code compliance for the full installation, verified at the local jurisdiction level.

And one more thing: warranty language on the battery cells. CATL's typical EV battery warranty is around 8 years, but stationary storage terms differ — so read the coverage exclusions. "Pro-rated" warranties are, from my perspective, mostly marketing. If the cell degrades faster than the datasheet promises, you want a straight replacement, not a refund formula.

Our own 12-point verification checklist, created after year one of procurement mistakes, has saved us an estimated $18,000 in potential rework across the last 18 months. That's the real return on prevention.

Common mistakes to avoid

A few things I'd push back on if you hear them from a vendor:

"We've been in the industry for a decade." Fine. Show me current certifications, current delivery records, and current references — not a founding story.

"It's just a solar panel." No. It's a module with a datasheet. Ask for the model number. Always.

"Level 3 is future-proofing." Maybe. But if your vehicles sit overnight, Level 2 covers 95% of the need, and you can add a DC fast unit later if shift patterns change.

Finally, keep dates on your data. The CATL China EV battery market share figure for 2024 was roughly 43% per CABIA — but by the time you're reading this in a later quarter, it will have moved. Naxtra production volumes for 2026 are projections, not purchase orders. Verify current rates, current standards, and current supplier status before you sign.