Walk through any lithium battery listing on Amazon or eBay and you'll see "Grade A cells" splashed across every product. The phrase is essentially marketing - there's no industry body issuing Grade A certificates, and most cell suppliers grade their own output internally. A "Grade A" cell from one factory can be a "Grade B" reject at another.
What actually matters is which production batch the cell came from, and what the individual cell tested at when it was made. Two cells with the same printed capacity (say 280Ah) can vary by 5-10Ah in real-world delivery. Put four mismatched cells in series and the weakest one becomes the limiter for the whole pack - that's the cell that hits low-voltage cut-off first, the cell that ages fastest, and ultimately the cell that defines how long your battery lasts.
So when we say "Class A", we mean the top tier of our grading spec - not the cell supplier's marketing label.
Where our cells come from
The vast majority of our range uses cells from EVE Energy, with a smaller number of larger-format models built around CATL cells. Both are top-tier global manufacturers of prismatic LiFePO4 cells - the same families of cells that go into commercial EVs and grid-scale storage. We don't buy from the unbranded re-sellers that flood the consumer market.
We use prismatic cells specifically - not pouches, not cylindricals - because:
Higher energy density per litre than cylindricals, so the finished battery fits standard DIN automotive footprints.
Mechanical stability - prismatic cells have rigid metal cases that don't swell or deform under load like pouches.
Even thermal behaviour - the flat geometry means heat dissipates uniformly through the BMS heatsink, not in hot pockets.
Longer cycle life at deep discharge - typically 6,000+ cycles to 80% capacity at 1C, where consumer-grade cylindricals manage 2,000-3,000.
The trade-off is cost. A premium 280Ah EVE or CATL prismatic cell costs roughly 3x what a no-name 280Ah cell costs on AliExpress. We think that's the right trade for a battery you expect to last 20 years in your motorhome.
The factory grading process
Our partner factory works to our written grading spec, not theirs. The process below runs on every cell before any of them are allowed to go into a TITAN-branded battery casing. We've worked with the same factory for years - they share our "quality over throughput" mindset, which is why this arrangement works at all. Most factories won't entertain rejecting 90% of their own output.
Stage 1
Visual & physical inspection
Casing · Terminals · Manufacturing date
Every cell is checked under direct light for casing dents, terminal corrosion, electrolyte weep marks at the seal, and the date code printed on the side. Cells more than 6 months old at the point of build get pushed back to the cell supplier - older cells have already spent some of their calendar life sitting on a pallet.
Reject rate Roughly 1 in 100 cells fail this stage outright (usually a casing dent from transit). These get returned to the cell supplier under warranty.
Stage 2
Full capacity test
Charge to 100% · Discharge to 0% · Real Ah measurement
Each cell is hooked up to a calibrated charger/discharger and put through one full charge-discharge cycle. The actual amp-hours delivered are measured - not the printed nameplate value - and logged against the cell's serial number. A nameplate 280Ah cell typically delivers anywhere between 275Ah and 295Ah; only cells testing at nameplate or above make the cut.
Reject rate Around 30-40% of cells in any given batch test under nameplate. They're not "broken" - they just go to other manufacturers who'll print whatever capacity they want on the label.
Stage 3
Internal resistance (IR) check
Milliohm measurement · AC injection method
Internal resistance is the single best predictor of how a cell will age. A new 280Ah prismatic cell should read between 0.18 and 0.25 milliohms. Cells reading higher than 0.30 mΩ - even if they passed the capacity test - get filtered out, because high IR means the cell will heat up faster under load, sag harder under high current draw, and lose capacity faster over its lifetime.
Reject rate Another 20-30% drop out at this stage. These cells often work fine in low-current applications, but they're not what we're building.
Stage 4
Matched-pack assembly
Capacity grouping · IR grouping · 4 cells per 12V battery
The cells that survive the previous three stages get sorted by tested capacity and IR, then grouped into matched fours (for a 12V battery) or eights (for a 24V battery). Every cell in your specific battery has a measured capacity within 1Ah of every other cell in the pack, and an IR reading within 0.02 mΩ. That's what stops the weak-cell-defines-the-pack problem before it can start.
Final yield About 1 in 10 cells from the original pallet make it into a TITAN battery. The rest go to other lithium manufacturers.
End-pack QC in Cheltenham
Once the assembled packs reach our workshop in Cheltenham, the testing isn't over. Every battery is unboxed and run through the same pre-shipping checklist before it goes back into its packaging:
BMS pairing & firmware check. Every battery is connected over Bluetooth, the BMS firmware is verified, and the comms package is locked down so third-party apps can read data but not write parameters (more on that below).
Pack-level capacity verification. A controlled charge-discharge cycle confirms the assembled pack delivers nameplate or above. Anything that doesn't matches gets stripped down and the cells go back through grading.
Voltage balance check. All four (or eight) cells should sit within a few mV of each other at rest. Out-of-balance packs get held back for active balancing before shipping.
Heater and Bluetooth function test on heated models.
Only after the pack passes every one of those checks does it get the TITAN serial sticker, the warranty record, and the green light to ship.
What this means for you
Three things that show up in real-world use:
Higher delivered capacity than the label says. A TITAN 150Ah typically tests at 160-165Ah out of the box, because nothing under nameplate makes it past Stage 2. Most competitor 150Ah batteries deliver 140-150Ah.
Slower capacity fade over time. Matched-IR packs heat evenly and balance evenly, which is the single biggest factor in long-term capacity loss. Expect 5-10% loss per decade with normal use, vs 15-25% from a mismatched pack.
No "weak link" cell failure. The most common death mode for cheap lithium packs isn't a cell wearing out - it's one mismatched cell hitting low-voltage cut-off years before the others, dragging the whole pack into early retirement. Matched packs don't do this.
See the range
Every battery in the TITAN range goes through this exact process. The capacity printed on the label is the minimum you'll get out of the box, and every cell in the pack is matched.
