NOCO GENIUS1 vs Battery Tender 021-0123

Buy the NOCO GENIUS1, model GENIUS1, UPC 046221190021, ASIN B07W46BX31, when you want the 1-amp charger whose title says 6 volts and 12 volts and whose item-type line repeats both, and when you will notice that the output-voltage cell says only 12 volts. Buy the Battery Tender Junior, model 021-0123, ASIN B000CITK8S, when you want the 12-volt, 750-milliamp maintainer, and when you will ignore an input-voltage cell that also says 12 volts and a dimensions bullet that does not match the dimensions cell. These are battery chargers. They belong on a boat battery, a trolling-motor battery, or a small starting battery. They are not battery switches and they are not the battery.

Short version. A boat battery that will not crank is the failure these boxes are meant to prevent. A Blue Sea 6006 and a Perko 8501DP choose which battery is online. A Rule pump is what a live battery is often asked to run. Charge the battery. Then select it. Do not confuse the charger with the switch.

The NOCO title is GENIUS1, 1 amp, 6/12 volt, smart charger, trickle charger, and maintainer, for lead-acid wet, gel, and AGM, and for lithium including LiFePO4. The brand cell and the manufacturer cell say NOCO. The model number and the manufacturer part number both read GENIUS1. The UPC is 046221190021. The GTIN is 00046221190021. The ASIN is B07W46BX31. The color cell says Black. The item-weight cell says 15.2 ounces. The product-dimensions cell says 4.02 inches deep, 3.43 inches wide, and 6.73 inches high. The size chip says 1A. The output-voltage cell says 12 volts. The input-voltage cell says 120 volts. The current-rating cell says 1 A. The amperage cell says 1. The battery-charge-time cell says 1E+1 hours. The connector cell says battery clamps and eyelet terminals. The number-of-ports cell says 1. The number-of-items cell says 1. The unit-count cell says 1. The warranty-description cell says 3 Year Limited. The compatible-devices cell lists cars, boats, motorcycles, ATVs, RVs, trucks, SUVs, scooters, lawn mowers, and tractors.

The output cell saying 12 volts is the conflict with a title and an item-type name that both say 6 and 12. A charger can have a 12-volt output mode and a 6-volt output mode. A cell that prints only 12 is not a denial of the 6-volt mode, and it is not proof of it. The title and the item-type line are where 6 volts lives. The output cell is where 12 volts lives alone. If you are charging a 6-volt bank, do not cite the output cell as your proof. Cite the title, and then confirm the mode button on the unit, because the cell will not back you up. The input cell says 120 volts. That is a wall-plug figure. It is the cell the Battery Tender card gets wrong. The current-rating cell says 1 A and the amperage cell says 1. Those agree with the 1-amp title and with the 1A size chip. One amp is the rate, not the battery size.

The charge-time cell says 1E+1 hours. That is scientific notation for 10 hours, written the way a spreadsheet writes a number it did not format. It is not a model code and it is not 1 hour. Read it as 10 hours only if you are willing to translate the cell, and do not pretend the card printed the word ten. The card does not say 10 hours of what battery. A 1-amp charger takes a long time on a big house bank and a shorter time on a small starting battery. 1E+1 is not a sizing chart. The weight cell, 15.2 ounces, matches a charger you can lift in one hand. The dimensions cell is the box you measure. The built-in-media line lists a 3-year limited warranty, a user guide, the GENIUS1, and needle-nose clamps with integrated eyelet terminals. That is the packing list the card is willing to print. The connector cell agrees: clamps and eyelets. The card does not print a separate 12-foot cord length. Do not borrow a cord length from the Battery Tender bullets.

The Battery Tender title is Junior, 12 volt, 750 mA, model 021-0123. The brand cell says Battery Tender. The manufacturer cell says Deltran. The model number and the manufacturer part number both read 021-0123. The GTIN is 00734357000078. The ASIN is B000CITK8S. The color cell says Black/Green. The size chip says 12V @ 750mA. The output-voltage cell says 12 volts. The input-voltage cell says 12 volts. The current-rating cell says 750 milliamps. The amperage cell says 0.75 A. The product-dimensions cell says 2.9 inches deep, 2.15 inches wide, and 4.4 inches high. The connector cell says alligator clips and ring terminals. The number-of-ports cell says 1. The number-of-items cell says 1. The unit-count cell says 1. The specification-met cell says CSA, ETL, FCC. The external-testing-certification cell says Não Aplicável. The warranty-description cell says Manufacturer Warranty. The item-type name says BATTERY_CHARGER. The what's-in-the-box line says Battery Tender 021-0123. The built-in-media line says the same.

750 milliamps and 0.75 A are the same rate written two ways. They agree with the title and with the size chip. They do not agree with the NOCO's 1 A, and they should not. This is the smaller charger. The output cell says 12 volts and the title says 12 volts. This card does not claim a 6-volt mode. Do not put it on a 6-volt bank because the NOCO title had a 6. The input-voltage cell says 12 volts. A wall charger does not eat 12 volts from the wall. The NOCO input cell says 120 volts, which is the outlet. The Battery Tender input cell copied the battery voltage into the outlet field. The bullet that lists a 12-volt charger is talking about the battery side. Cite 12 volts as the battery. Do not cite the input cell as the plug.

The dimensions cell says 2.9 by 2.15 by 4.4 inches. A bullet says the charger is just 3.3 by 1.3 by 2.4 inches and 1 pound, charger only. Those two size lines are not the same object described the same way. 1 pound is 16 ounces. The NOCO cell says 15.2 ounces, which is just under a pound. The Battery Tender card prints 1 pound in a bullet and does not print an item-weight cell you can set beside it. Measure the brick. Do not average 2.9 inches with 3.3 inches. The bullet also says a 12-foot output cord, a fused-ring terminal harness, and alligator clip accessory cables. The connector cell says alligator clips and ring terminals, which agrees with the hardware and does not repeat the 12-foot length. The what's-in-the-box line names only 021-0123. The cord and the clips are in the bullet. Open the bag. If the ring harness is missing, the bullet was the promise.

The certification cell says CSA, ETL, FCC. The external-testing-certification cell says Não Aplicável, which is Portuguese for not applicable. Two certification cells disagree in two languages. CSA, ETL, and FCC are the English cell. Não Aplicável is the broken cell. The warranty cell says Manufacturer Warranty. The bullet says a 5-year warranty and lifetime customer support. Five years is the bullet. "Manufacturer Warranty" is the cell that forgot the number. The NOCO cell says 3 Year Limited and the NOCO media line repeats 3 years. The Junior's years live in the bullet only. The chemistry bullets name 12-volt lead-acid, flooded, AGM, and gel. They do not name lithium. The NOCO title and the NOCO item highlight name lithium, including LiFePO4. If the battery is lithium, this Junior card is the one that never said so. The compatible-devices story on the Junior page is in the bullets and the on-page questions: motorcycles, ATVs, personal watercraft, and a 3-to-30-amp-hour band in those questions. The questions are not a specifications cell. Quote them as questions on the page, not as a second dimensions cell.

Who should buy the NOCO, and who should buy the Battery Tender?

Buy GENIUS1 if you want UPC 046221190021, the 1-amp cells, the 120-volt input cell, the clamps-and-eyelets line, and a title that names 6 volts, 12 volts, and lithium, and if you will remember that the output cell prints only 12 and that 1E+1 hours is a spreadsheet's way of writing 10. Buy 021-0123 if you want a 12-volt, 750-milliamp maintainer, GTIN 00734357000078, alligator clips and ring terminals, and the 5-year bullet, and if you will ignore a 12-volt input cell, a Portuguese certification cell, and a dimensions bullet that fights the dimensions cell. Buy the NOCO for a boat that still has a 6-volt lighting bank or a lithium trolling battery the Junior bullets never named. Buy the Junior for a 12-volt lead-acid starting battery you are willing to charge more slowly.

Do not buy either box as a battery switch. The 6006 and the 8501DP do that job. Do not buy the Junior for a lithium battery this card does not name. Do not buy the NOCO because 1E+1 looked like a one-hour charge. Do not buy a second unit to fix a cell. One order is one charger on both cards. A pack-of-two chip, if the page shows one, is a different selection.

What is the GENIUS1 card actually selling?

A 1-amp smart charger with a wall input the cell calls 120 volts and a battery output the cell calls 12 volts, plus a title that adds 6 volts and lithium. The useful identity is GENIUS1, the UPC, 15.2 ounces, the dimensions cell, black, one port, clamps and eyelets, boats in the compatible-devices cell, and a 3-year limited warranty cell. 1E+1 hours is the charge-time cell you translate or you do not quote. The media line is the packing list: charger, guide, clamps with eyelets, and the warranty. The card does not print a cord length. The card does not print an app. Force mode and desulfation are in the title's highlight, not in a numbered cell. They are claims you can read and not a second amperage.

Use the mode the battery actually is. A 12-volt AGM and a 12-volt lithium setting are different even when both are 12 volts and the output cell cannot tell them apart. The title is how you know the modes exist. The button on the charger is how you select them. This page does not print a picture of the button labels in a cell. If the unit you unpack has no 6-volt mark, the title over-promised and the output cell was the honest one. Boats are named in the compatible-devices cell. A boat battery under a deck still has to be the chemistry the mode matches. The charger does not know your switch position. Turn the selector off, or to the bank you mean, before you clamp. The 6006 card is the on-off conversation. This card is the charger.

What is 021-0123 actually selling?

A 12-volt, 750-milliamp charger and maintainer. The useful identity is 021-0123, GTIN 00734357000078, Deltran, black/green, 750 mA, 0.75 A, 12-volt output, alligator clips and ring terminals, and the dimensions cell of 2.9 by 2.15 by 4.4 inches. The 12-foot cord, the 1-pound line, the 3.3 by 1.3 by 2.4 bullet, and the 5-year warranty are bullets. The input cell that says 12 volts is the error. Não Aplicável is the error. "Manufacturer Warranty" is the cell that lost the five years. Lead-acid, flooded, AGM, and gel are the chemistries the bullets name. Lithium is not among them.

Float mode is the point of the bullets. A trickle charger that never stops is what the on-page answer says this unit is not. That answer is not a cell, and it is the reason the card keeps saying maintainer. Leave it on a 12-volt lead-acid battery through a layup only if you accept the bullet, and check the connection the bullet calls spark-proof. The card does not print a spark test. The 12-foot cord is how you reach a battery in a hatch without putting the brick in the bilge. The dimensions fight is why you measure before you promise the brick will fit a particular tray. One pound in the bullet and no weight cell means you do not have an ounce figure to compare with the NOCO's 15.2 ounces unless you weigh the Junior yourself.

How do you hook them up without mixing the cards?

Clamp the NOCO at 1 amp when you want the printed rate and the battery is a chemistry the title named. Clamp the Junior at 750 milliamps when the battery is 12-volt lead-acid and you are in no hurry. Do not stack them on one battery to go faster. Neither card prints a parallel-charger instruction. Do not use the Junior input cell as a reason to wire the brick to 12 volts of solar and expect the same behavior as the 120-volt plug. The NOCO input cell is the one that says 120. Match red to positive. The Junior bullets mention reversed-hookup detection. The NOCO highlight does not spell that sentence in a cell. Look at the clamps. A spark-proof claim is not a reason to clamp a battery with the selector feeding a live pump. Turn the load off first.

A charge-time cell of 1E+1 hours is not a promise that a group 27 boat battery is full before lunch. A 1-amp rate into a large bank is an overnight conversation at best, and the card does not print the bank size that matches 1E+1. The Junior's on-page questions talk about 3 to 30 amp-hours and about overnight charges for the small end. Those are questions, not the NOCO's cell. Use them only for the Junior, and only as the page's own Q&A. Storage charging is the layup job. A switch left on both is a different article. Charge one bank, then the other, unless you understand the selector you already own.

What actually fails on these two cards?

The NOCO card fails when the output cell's lone 12 volts is used to cancel the 6-volt title, or the other way around, when a 6-volt mode is assumed on a unit whose button never shows it. It fails when 1E+1 is read as one hour or as a part number. It fails when a cord length is imported from the Junior. It fails when lithium in the title is ignored and a lead-acid mode is left on a LiFePO4 bank. It fails when boats in the compatible-devices cell is read as a marine ignition rating the card does not print.

The Junior card fails when the input cell's 12 volts is wired as if the wall were 12. It fails when the two dimension lines are averaged. It fails when Não Aplicável is read as a certification that cancels CSA, ETL, and FCC, or as a certification of its own. It fails when the 5-year bullet is ignored because the warranty cell is vague, or quoted as a cell when it is a bullet. It fails when a lithium battery is attached because the NOCO on the same bench said lithium. It fails when the what's-in-the-box line is obeyed and the ring harness is never unpacked.

What is this comparison not?

This is not a claim about which charger recovers a dead battery from zero volts. The NOCO title mentions force mode. The card does not print a minimum voltage in a cell. The Junior's on-page answer mentions batteries below 2 volts. That is an answer, not a cell, and it is not the NOCO's number. This is not every NOCO amp size. GENIUS1 is the 1-amp model. A GENIUS5 or a GENIUS10 is a different model and a different rate. This is not every Battery Tender. 021-0123 is the Junior 750-milliamp card. A 5-amp Tender is a different part. This is not a price quote. Use the buttons. This is not a switch comparison and it is not a pump comparison.

So which charger should you buy?

Buy the NOCO if you want model GENIUS1, UPC 046221190021, 1 amp, a 120-volt input cell, a title that names 6 volts and lithium, and a 3-year warranty cell, and if you will translate 1E+1 and remember the output cell says only 12. Buy the Junior if you want model 021-0123, 750 milliamps, a 12-volt lead-acid bullet, and the 5-year bullet, and if you will throw out the 12-volt input cell, the Portuguese certification cell, and the dimensions line the tape rejects. Buy neither if you wanted a battery switch, a lithium charge from a card that never said lithium, or a one-hour fill of a big house bank. The model number is the decision. The copied voltage cells are the warning.

Jose's Extreme DIY film, "Noco Genius One Battery Charger and Maintainer Tutorial and Test," shows a NOCO GENIUS charger and walks the modes, including a 6-volt selection and a 12-volt selection. The title says Genius One. The clip does not show the Battery Tender Junior or model 021-0123. Use it for the NOCO buttons. Do not use it as a reading of the Junior's 12-volt input cell or of the 2.9-inch dimensions cell.