Gonine 21V Lithium Battery Charger for 20V 21V Review
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The gonine 21v lithium battery charger for 20v 21v review answers one practical question: will this charger match the battery on your yard tool? The listing describes a single 21V, 1A charger with a round DC plug, aimed at 20V and 21V lithium-ion packs used with mini chainsaws, drills and similar tools. This page sets out what the listing states, where its fields disagree, and which buyers should look at a different charger. Read the compatibility checks before you order. A charger with the wrong voltage or port will not work, whatever the listing says about charging speed. Battery platform details always come from the manufacturer, so treat this guide as a checklist.
Quick answer
Buy this charger only if your tool battery is a 20V or 21V lithium-ion pack with a round DC jack and you want a 1A charger for it. The listing states 21V DC output at 1A, a 1.2M power cable, and LED indicators for charging and full charge. It does not state that a battery is included, so plan to supply one. Skip it for 18V, 24V or 40V packs, for nickel or lead-acid batteries, and for any battery whose charging port is not round. Before ordering, resolve the input voltage conflict on the listing, because it gives two different figures.
Best for and avoid if
Best for
Owners of 20V or 21V lithium-ion tools who need a spare charger for a smaller pack. The listing’s 1A output and one-year warranty suit a buyer who charges slowly and wants the unit on a wall. The listing also gives a wall mount type, which helps if the charger lives in a garage or shed.
Avoid if
Your battery is a different voltage or chemistry, or its charging port is not a round DC jack. Skip it if you expect a battery to arrive in the box, since the listing does not state one is included. Buyers who need a higher-current charger for a large pack should compare other options first.
Products that fit this
The product card below carries the listing’s specifications, pros and cons for this single charger. Read its skip condition before you buy, then use the compatibility checks further down this page to confirm the battery.
1. 21V Lithium Battery Charger, for 20V 21V Power Tools – Compatible with Leaf Blower, Mini Chainsaw (Best fit for 20V and 21V lithium-ion tool batteries)
Specs from the listing (checked 2026-10-14):
- Output Voltage: 21 volts_of_direct_current
- Output Current: 1 A
- Wattage: 21 watts
- Power Cable Length:: 1.2M
- Mounting Type: Wall Mount
- Warranty Description: 1 Year Warranty
- Specification Met: CE, FCC
Pros
- The listing states a 21V 1A DC output, which matches the 20V and 21V class it names.
- The listing gives a 1.2M power cable, which is 3.9FT in the bullets.
- The listing states LED indicators, red while charging and green when fully charged.
- The listing states a one-year warranty and lists CE and FCC marks.
Cons
- The listing does not state that a battery is included; only one charger is listed as included.
- The listing gives input voltage as 120 volts in one field and 100-240V AC in another, so the input range needs checking.
- The listing's Compatible Phone Models field names only chainsaw models, while the title names other tools.
- The listing claims 30% faster charging without naming a baseline charger.
Best for: Owners of 20V or 21V lithium-ion tools who need a spare charger with a round DC jack and a one-year warranty.
Skip if: Skip it if your battery is 18V, 24V or 40V, uses nickel or lead-acid chemistry, or has no round DC jack.
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Verified specifications from the listing
The points below are copied from the listing fields and bullets. They describe the charger only, because no battery is part of the listing.
| Specification | Listed value |
|---|---|
| Output | 21V DC at 1A (labelled DC 21V 1A) |
| Wattage | 21 watts |
| Input | 100-240V AC, 50-60Hz (a separate field reads 120 volts) |
| Plug | Type A, 2-pin (North American/Japanese) |
| Power cable | 1.2M (3.9FT) |
| DC port | Round jack, 5.5*2.5mm, compatible with 5.5*2.1mm |
| Included | One 21V 1A battery charger |
| Mounting | Wall mount field; hardware inclusion not stated |
| Warranty | 1 year |
| Certifications | CE, FCC |
| Manufacturer | ShenZhen JiuZhou Power Technology CO., LTD., model JZB 024-2101000UX |
| Enclosure | Metal and plastic |
Compatibility checks before you buy
The listing sets out three checks. Work through them in order, using the printed label on your battery rather than memory.
- Voltage: the listing says the battery must be 20V or 21V lithium-ion (NOT 18V/24V/40V).
- Port: the listing says the charger needs a round DC jack, 5.5×2.5mm or 5.5×2.1mm.
- Use: the listing names mini chainsaws, drills and wrenches from several brands. It also says the charger will not work with Ni-MH/lead-acid batteries.
Two points need extra care. First, the listing gives input voltage as 120 volts in one field and as 100-240V AC in its specifications and bullets, so the input range is unclear from the listing alone. Second, a field labelled Compatible Phone Models lists only chainsaw models, while the title also names leaf blowers, hand drills, electric wrenches and screwdrivers. Rely on neither field by itself.
The listing does not name a lawn mower, a mower battery brand or any other brand’s pack as compatible. A matching voltage alone does not prove a fit, so check your own tool’s battery platform information with its manufacturer.
Charging behaviour and safety
The listing describes red LED lights while charging and green when fully charged. It also lists built-in overload protection, short-circuit prevention and temperature control. It claims 30% faster charging from an onboard chip, but it does not name the charger it compares against, so read that figure as the manufacturer’s claim.
Battery chargers store energy by sending current into the battery, and the right method depends on the battery’s size and type. Some battery types cannot tolerate overcharging and can be damaged, lose capacity or overheat. Chargers may use temperature or voltage sensing, but those circuits do not replace the battery maker’s instructions.
Lithium-ion cells typically have a nominal voltage of 3.6 or 3.7 volts, and battery sizes are not standardized. Match the pack’s printed voltage rather than counting cells or assuming a size from appearance.
Store and charge the battery as its manual directs. This page does not offer battery repair advice. If a pack will not charge, follow the manufacturer’s service route.
Strengths and limitations
Strengths
- A single 21V 1A output that matches the 20V and 21V class the listing names.
- A 1.2M power cable, with LED status lights.
- A one-year warranty, and CE and FCC marks listed.
Limitations
- No battery is included in the listing.
- The input voltage figures conflict, so the input range needs checking.
- The voltage and port match is narrow, and the listing names no lawn mower.
- The listing gives no charge time, so the 1A output cannot be turned into a schedule from the listing alone.
Alternatives to consider
If the checks above fail, a different charger is the right purchase. Start with the battery’s printed voltage and chemistry, then use these guides on this site:
- smart charger guide for lithium and lead-acid batteries
- lawn mower battery voltage and amps guide
- charging system guide for lawn mowers
- lawn and garden battery voltage guide
- guide for a lawn mower battery that will not charge
These guides cover other voltages and chemistries, so they answer the question this charger cannot.
Worked example: rough charge-time planning
A common rule of thumb divides battery capacity by charge current to get a rough hour count.
- Step 1: 2.0 Ah ÷ 1 A = 2.0 hours of ideal charging.
- Step 2: Losses and the taper near full charge make real charging longer than this rough figure.
- Result: about 2 hours before losses. Check the battery manufacturer’s stated charge time for your own pack, since the listing does not state one.
FAQ
Will this charger fit my 20V tool?
It fits only if the battery is 20V or 21V lithium-ion and has a round DC jack, as the listing says. Voltage alone does not settle fit, so check the port size as well.
Does the box include a battery?
The listing states one 21V 1A battery charger is included and does not list a battery. Plan to supply your own pack.
What protections does the listing describe?
The listing describes overload protection, short-circuit prevention and temperature control, along with a short-circuit protection feature. These are the manufacturer’s descriptions, and the listing gives no test standard for them.
How long will a charge take?
The listing does not state a charge time. Use the rough estimate in the worked example only as a starting point, and take the real figure from the battery manual.
What do the indicator lights mean?
The listing says red means charging and green means fully charged. If the lights behave differently, follow the battery and charger manual rather than this page.
Can I charge a lead-acid or nickel battery with it?
No. The listing states the charger will not work with Ni-MH or lead-acid batteries.
Why does the listing show two input voltages?
One field gives 120 volts, while the specifications and bullets give 100-240V AC. Read the printed label on the charger you receive and confirm the supply it needs before you plug it in.
Bottom line
Buy this Gonine charger if your battery is a 20V or 21V lithium-ion pack with a round DC jack, you accept that the listing gives no charge time, and you will supply your own battery. Skip it for any other voltage or chemistry, and settle the input voltage question before you plug it in. Decision rule: if the pack label reads 20V or 21V lithium-ion and the port is round, the charger deserves a closer look. If not, choose a charger that matches the label.
Sources
- Wikipedia: Battery charger: charging current, overcharging damage and temperature or voltage sensing circuits.
- Wikipedia: Lithium-ion battery: nominal cell voltage of 3.6 or 3.7 volts and non-standard battery sizes.