Experience with DATOUBOSS 12V 100Ah LiFePO4 batteries that measured ~86Ah and return process through Amazon

Had almost identical experience with a no-name 100Ah LiFePO4 from Amazon a while back — tested it properly with a proper discharge cycle and landed somewhere around 84Ah. Seller was advertising "actual capacity" in the listing as well, which made it worse.

The Amazon return process for batteries is genuinely hit and miss. Got mine collected no problem, but I've heard others getting the runaround because lithium batteries technically fall into the hazardous goods category for couriers. Worth checking whether the seller is fulfilled by Amazon or third-party, as that seems to make a big difference to how smoothly it goes.

My advice if you're going through it now:

• Open a return request through Amazon directly, not the seller
• Photograph your capacity test results if you have them (cycle data from a battery analyser, etc.)
• If they push back, mention "not as described" specifically — that tends to cut through

Honestly this whole space is a bit of a minefield. I ended up switching to Fogstar Drift cells after the dodgy Amazon experience and the difference in quality is night and day. More expensive upfront but you actually get what it says on the tin.

Curious whether others have managed to do independent capacity testing before initiating the return — does Amazon ever accept that as evidence, or do they just take your word for it? Also wondering if DATOUBOSS specifically have improved their QC recently, as I've seen a couple of positive reviews crop up lately. Would be useful to know if it's batch dependent.

@WhatsAFuse — par for the course with these mystery-brand cells, honestly. I went through exactly this rigmarole with a suspiciously cheap 200Ah unit for the narrowboat a few years back. Measured 178Ah on a proper 0.2C discharge. Not catastrophic, but not what I paid for either.

The Amazon return process for batteries is a genuine lottery. Hazmat classification means some fulfilment centres simply won't accept them back, and suddenly you're in a 45-minute chat loop with someone reading from a script.

My advice — document everything before you even think about returning. Video the capacity test with timestamps, screenshot the listing, keep the original packaging. Amazon A-to-Z claim is your friend if the seller goes quiet.

Fogstar and Fogstar Drift have genuinely honest capacity ratings if you want to avoid this circus next time. Pay a bit more, sleep better.

@WhatsAFuse the 84-86Ah figure on a "100Ah" no-name cell is almost suspiciously consistent — suggests they're binning genuine ~85Ah cells and just... lying about the label. Classic.

For the Amazon return, key thing people miss: photograph your discharge test data before initiating the return. Screenshot your BMS app, your cycle count, your actual measured capacity. Amazon sellers frequently contest "not as described" claims without evidence, then suddenly a blurry photo of a capacity tester reading 86Ah becomes your best mate.

Worth noting — this is precisely why I went Fogstar Drift for my cabin build. Slightly pricier but they publish actual test data per batch. Victron obviously integrates beautifully but the cost per kWh is eye-watering compared.

If the seller drags their heels on the return, Section 75 or a chargeback via your card provider is surprisingly effective leverage even on marketplace purchases.

@DailySolar that consistency point is exactly what gets my goat. If they know they're shipping 86Ah cells and slapping 100Ah on the label, that's not a binning quirk — that's deliberate misrepresentation.

Had a similar headache with a mystery-brand cell I chucked into the motorhome two summers back. Tested at 83Ah. Raised a dispute through Amazon and they refunded without even asking for a return — which tells you something about what they think the product is worth.

Lesson learned: I now only buy cells where someone reputable — Fogstar, Fogstar Drift, occasionally Daly BMS units from known suppliers — has actually stood behind the spec. Costs more upfront but you're not sat on a towpath in Shropshire wondering why your fridge cut out at noon.

Save yourself the grief and budget properly first time.

@AngliaCamper raises a fair point, and honestly that consistent 84–86Ah figure across so many different "brands" tells its own story.

@WhatsAFuse — welcome to the forum, by the way! Good first post, and the fact you actually ran a proper discharge cycle puts you ahead of most people who just trust the label.

Worth knowing for next time: established cells from suppliers like Fogstar or EVE-based units from reputable UK sellers come with actual test data per cell. Slightly more outlay upfront, but you're not playing the capacity lottery.

On the Amazon return — document everything with screenshots and timestamps. Their A-to-Z guarantee has worked for members here in similar situations, especially when you can demonstrate measurable misrepresentation rather than just "didn't like it."