5.0 out of 5 stars It works.

2026-01-25    -Richard Frazier

So far so good at starting my boat and car when needed.

Excellent product

2025-12-23    -TR

Pros• 4‑in‑1 tool: charger, tester, desulfator, and maintainer in one compact unit• Works with all 12V lead‑acid batteries (AGM, GEL, EFB, Flooded) for cars, bikes, RVs, boats, and lawn equipment• Smart 8‑stage charging with temperature compensation for safer, optimized charging• Real‑time diagnostics: SOH, voltage, internal resistance, cranking test, alternator test• Automatic maintainer mode for long‑term storage—no need to monitor or unplug• Strong safety protections: over‑voltage, over‑current, reverse polarity, overheating, and more• Backlit LCD with history recall and quick FN hotkey for fast testing or charging• Durable, IP65 waterproof housing suitable for indoor/outdoor useCons• SAE cables not included—motorcycle users may need to remove battery covers to charge• Slightly larger and heavier than basic trickle chargers• Currently unavailable on Amazon Canada (as per listing)• More advanced features may be overkill for users who only need a simple chargerSummaryThe FOXWELL BC521 is a feature‑rich, professional‑grade 4‑in‑1 battery tool that handles charging, diagnostics, repair, and long‑term maintenance with impressive accuracy. Its smart 8‑stage charging, real‑time testing, and strong safety protections make it ideal for anyone who wants reliable battery care for cars, motorcycles, RVs, or boats. If you want a single device that can diagnose, revive, and maintain your batteries, this is an excellent choice.

OK

2026-02-11    -"ajm72"

I looked up this item online and I can find no reference to this model anywhere, even on the Foxwell website, so I'm slightly dubious.It seems to do a good job of reporting on the status of batteries, and appears to be very comprehensive. However I haven't worked up the courage to charge a battery with it yet.

5.0 out of 5 stars Good charger

2026-02-23    -Joe

Just tested it out on Trustart battery which is an 84 month battery installed on 9/22z . It was receiving 99% soc. Great charger. It did take a full day and night to reach this on fast charge mode.

4.0 out of 5 stars Nesesario tenerlo

2026-02-24    -justo g perdomo

Muy practica para prevenir daños en la bateria

5.0 out of 5 stars Good battery charger

2026-01-26    -KC Kid

Works as advertised. Screen is easily visible.

Very nice product!

2025-12-24    -Ron Jeremy

I've used this battery charger on pretty bad batteries so far, and I have been able to revive them enough so that they could be used again. For exemple, I use a snow plow on my ATV and it uses the winch to raise and lower it. Since there is no alternator on it, it seems that with frequent use the battery gets drained to a point where after a month or so of use it gets hard to start when cold. I have used this charger to "repair" my almost 5 years old battery to pretty much like new! Now it cranks like it should, and you can tell that the winch as enough power by it's sound! After this experience I have used it on my motorcycle, my lawn mower, and even my car. All my batteries are a couple years old, and so far I have been able to "repair" or "restore" weak older batteries to usable again! considering the price of batteries, I think that this little charger is a great buy! Super easy to use and it comes with a nice semi rigid case for storage. I would 100% recommend it!

A excellent performers and form factor.

2026-02-19    -Blackrain

This FOXWELL battery charger is amongst some of the best devices of it's kind that I have used to date. It is truly impressive in how easy it is to use, how capable it is to service many different batteries and how well it is built. The compact size also makes it very convenient to have on the go.This combination of battery charger, charge maintenance and desulfator make this a truly "multipurpose" device.The charger features multistage smart charging system and allows you to select from 1A, 3A or 5A. This is a fantastic feature as it gives you more control over the power flow that might be best for a specific application. Compatible with 12V lead-acid batteries (AGM, GEL, EFB, Flooded) for cars, motorcycles, RVs, boats,and lawn equipment.Being a smart device, this analytical charger adapts to battery composition and condition for efficient, safe charging. The incorporated battery tester displays real-time metric concerning the battery voltage, amperage and state of health. Should the battery be in a poor state there is a chance to recovery some of the health by way of the "pulse repair mode" that helps to restore sulfated or poorly maintained batteries to a more functional condition.The alligator clips and cables are quite robust and will shielded. I expect these will last for some time. Thr overall construction quality of the unit casing and seals are of an elevated quality.This device features easy to use one-touch controls on the top surface that includes a programmable function button that you can set of you repeatedly use the same setup. This saves time in not having to make your required selections each time, if it was thebsame as your last. The display on this device is very clear to read and the backlighting is a really nice touch.This device carries multiple international electrical safety designations and incorporates safety features such as reverse polarity, short-circuit, overcharge and overheat protection.A few things should be noted...This is a 12v battery charger only. It is an AC plug in device and not a stand alone charging pack. Direct DC charging is NOT supported and finally, the cables are NOT very long so this device needs to be relatively close the the battery that it is servicing.This device is ideal for cars, SUVs, light trucks, yard equipment, boats, motorcycles etc...I have tested a number of these devices and this device is as good as any of the top contenders. It is my experience that the FOXWELL brand is a solid and reliable performer.Definitely recommended.

Well worth the money

2026-03-05    -Deb from Oz

This incredible all-in-one battery maintenance tool handles everything from your car and truck to your RV, boat, and golf cart, functioning as a trickle charger, quick charger, tester, and battery repair device. Its advanced design features both indicator lights and an LED display for clear, real-time monitoring of the process, which is made easy to understand with a comprehensive, well-written instruction booklet. Although it's not a cheap purchase, its reliability, extensive features, and durable construction—including a handsome hard-shell carrying case with a pocket for the instructions—make it a worthwhile investment that is clearly built to last.

5.0 out of 5 stars Revived my battery

2026-02-14    -Matt Morris

My car battery would only start if jumped. Even if I had let it run and drove it for an extended amount of time. The battery was at least 5 years old. I let the battery charge over night on the restore setting and it fixed the battery. Cranks up like a champ now.