Best Car Battery Memory Saver Under $30: 5 Picks Compared

A battery swap that wipes radio presets and learned settings is a small job that turns into a long reset session, and the best car battery memory saver under $30 is the cable that keeps power on the vehicle computer while the battery comes out. The picks below connect through an OBD2 port or a lighter socket, and they differ in power source, display and safety features.

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Picks for the garage

#	Product	Shop Score	Buy
1	MR CARTOOL OBD2 Car Memory Saver Cable	9.7/10	Buy on Amazon
2	All-Sun GK504 Automotive Setting Keeper Auto	9.4/10	Buy on Amazon
3	OBD II Connector Battery Memory Saver	9.4/10	Buy on Amazon
4	9V Battery Powered Memory Saver for Car Battery	9.4/10	Buy on Amazon
5	Memory Saver for Car Battery On-Board Computers	9.3/10	Buy on Amazon

1

MR CARTOOL OBD2 Car Memory Saver Cable

MR CARTOOL·9.7/10 Shop Score

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The Shop Score runs from 9.2 to 9.8 and weighs performance (35%), build (25%), value (25%), safety (10%, where it applies) and warranty (5%), using only what the manufacturer and the listing publish. How we pick ›

An OBD2 memory saver cable with voltage and current display, auto leakage detection, and safety protection for battery replacement.

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Pros

• Real-time voltage and current display during replacement
• Auto leakage detection by monitoring current values
• Audible alarm below 10V and above 14V, power-off above 16V
• Auto-polarity recognition and built-in 3A fast-blow fuse

Cons

• Can only be used as an emergency power supply, not for a long time
• No warranty term stated
• Requires a spare battery in addition to the cable
• Voltage range limited to 10 to 14V for operation

2

All-Sun GK504 Automotive Setting Keeper Auto

allsun·9.4/10 Shop Score

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The Shop Score runs from 9.2 to 9.8 and weighs performance (35%), build (25%), value (25%), safety (10%, where it applies) and warranty (5%), using only what the manufacturer and the listing publish. How we pick ›

A cigarette lighter memory saver with a hard plastic body for saving on-board computer memory data.

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Pros

• Plugs into any vehicle cigarette lighter
• Ruggedly designed hard plastic body
• Convenient, easy way to save memory data of on-board computers
• 1 Year warranty stated

Cons

• No voltage or current display stated
• No fuse or alarm stated
• Requires a 9-volt Alkaline battery, not included
• No safety feature stated beyond the hard plastic body

3

OBD II Connector Battery Memory Saver

PUXWQT·9.4/10 Shop Score

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The Shop Score runs from 9.2 to 9.8 and weighs performance (35%), build (25%), value (25%), safety (10%, where it applies) and warranty (5%), using only what the manufacturer and the listing publish. How we pick ›

A 16-pin OBD II memory saver with dual power options for sedans, SUVs and light trucks.

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Pros

• For all vehicles equipped with a 16-pin OBD II adapter
• Dual power options: 9V battery power and AC to DC adapter
• Includes a power adapter and a 9V connector
• Plug and play design with no complex settings

Cons

• No voltage or current display stated
• No warranty term stated
• No fuse or alarm stated
• Dual power options add a part to keep track of

4

9V Battery Powered Memory Saver for Car Battery

OCHIKI·9.4/10 Shop Score

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The Shop Score runs from 9.2 to 9.8 and weighs performance (35%), build (25%), value (25%), safety (10%, where it applies) and warranty (5%), using only what the manufacturer and the listing publish. How we pick ›

A 9V battery powered memory saver for 16-pin OBD II vehicles to protect settings during a battery swap.

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Pros

• Suitable for all vehicles with a 16-pin OBD II adapter
• Uses a 9V battery as a backup power supply for short-term power
• Protects settings, driving mode and personalized configuration in the ECU
• Plug and play, with no professional skills required

Cons

• No voltage or current display stated
• No warranty term stated
• No fuse or alarm stated
• Short-term power only, per the listing

5

Memory Saver for Car Battery On-Board Computers

Apopip·9.3/10 Shop Score

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The Shop Score runs from 9.2 to 9.8 and weighs performance (35%), build (25%), value (25%), safety (10%, where it applies) and warranty (5%), using only what the manufacturer and the listing publish. How we pick ›

A memory saver for car battery on-board computers that plugs into a 12 volt power receptacle with a 9V battery.

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Pros

• Saves drive-ability codes and settings when changing a starter battery
• Protects codes and settings for clocks and keyless entry systems
• Plugs into a 12 volt power receptacle, with a 9V battery
• Job finished in 15 minutes, per the listing

Cons

• Warranty description of OTHER is not a concrete term
• No material, display or fuse stated

Compared on paper

We copy each listing’s rated specs exactly as the manufacturer gives them; as of 30 October 2026. One of the five states a warranty term; the other four state no warranty term as a concrete term.

How the points were given

Each memory saver is scored on performance, build, value, safety and warranty, with the weights published on the How We Pick page. Safety points come from stated safety features: the MR CARTOOL cable states a fuse, auto-polarity recognition, a voltage alarm and power-off protection, while the other four state no safety feature of that kind. One listing states a warranty term: the allsun GK504 at 1 Year.

The displayed number is the weighted point total scaled linearly between 9.2 and 9.8. Earning more points is the only way up.

What the listings tell you

Five listings were compared. Three connect through an OBD2 port, two connect through a lighter socket or power receptacle, and power comes from a spare battery, a 9V battery, or an AC to DC adapter, depending on the pick. Only one lists a voltage and current display, and only one states a warranty term. The gaps are easy to miss on a small cable, so the connection type and the power source are the details to confirm before ordering.

How to choose the best car battery memory saver under 30

Connection first: OBD2 or lighter socket

Connection type decides whether a pick fits the vehicle at all. The MR CARTOOL, PUXWQT and OCHIKI picks connect through an OBD2 interface, with the PUXWQT and OCHIKI listings naming a 16-pin OBD II adapter for vehicles equipped with that interface. The allsun GK504 plugs into any vehicle cigarette lighter, and the Apopip pick plugs into a 12 volt power receptacle. Check the port in the vehicle before choosing, since an OBD2 cable cannot use a lighter socket and a lighter plug cannot use an OBD2 port.

Power source: spare battery, 9V battery, or adapter

Power source decides how long the saver can hold settings and what else must be on hand. The MR CARTOOL cable connects a spare battery and the vehicle OBD2 interface to an emergency power cable, and it is stated as a 12V cable. The PUXWQT pick offers dual power options, with 9V battery power and an AC to DC adapter option, and it includes a power adapter and a 9V connector. The OCHIKI and Apopip picks use a 9V battery, and the allsun GK504 requires a 9-volt Alkaline battery, which the listing states is not included. A fresh 9V battery matters on the Apopip pick, whose instructions state to make sure the 9V battery is new.

Figures as stated in each listing. A power source that is not included, such as the allsun 9-volt battery, must be bought separately.

Display and safety features

Only the MR CARTOOL cable lists a display. It shows battery voltage during replacement and current values, with a stated operating voltage range of 10 to 14V, an audible alarm when voltage is below 10V or above 14V, and power-off protection if voltage exceeds 16V. It also states auto-polarity recognition to prevent reverse connection damage and a built-in 3A fast-blow fuse for overload protection. The other four picks state no display and no fuse or alarm, so a leak or a depleted spare battery would not show up on those cables. The MR CARTOOL listing also states an auto leakage detection function, where current fluctuations are observed while fuses are removed in the fuse box, one by one.

Check the warranty line

Only the allsun GK504 states a warranty term, at 1 Year. The Apopip spec table states a warranty description of OTHER, which is not a concrete term, so it scores zero on warranty. The MR CARTOOL, PUXWQT and OCHIKI listings state no warranty term. A stated term is a small plus on a cable, but connection fit and power source matter more, since a saver that cannot connect or cannot stay powered cannot save settings at all.

Garage Fit Check

• Check for a 16-pin OBD II adapter or a cigarette lighter socket in the vehicle, since the picks split across those connections.
• Check the power source on hand: a spare battery for the MR CARTOOL cable, or a new 9V battery for the OCHIKI, Apopip and allsun picks.
• Check the MR CARTOOL operating voltage range of 10 to 14V, and note the alarm below 10V and above 14V.
• Keep the saver as a short-term bridge only, since the MR CARTOOL listing states it cannot power car computers for a long time.

FAQ: garage tools

Does a memory saver work on any car?

No, the connection must match. The PUXWQT and OCHIKI picks are for vehicles equipped with a 16-pin OBD II adapter, the allsun GK504 plugs into a cigarette lighter, and the Apopip pick plugs into a 12 volt power receptacle. Check the port before ordering.

What power does a memory saver need?

It depends on the pick. The MR CARTOOL cable uses a spare battery through a 12V cable, the PUXWQT pick offers 9V battery power and an AC to DC adapter, and the OCHIKI, allsun and Apopip picks use a 9V battery, with the allsun battery not included.

Can a memory saver power car computers for a long time?

No, these are short-term bridges for a battery swap. The MR CARTOOL listing states it can only be used as an emergency power supply for car battery replacement and cannot be used to power car computers for a long time, and the OCHIKI listing describes a short-term power supply for a trip computer.

Which pick shows voltage and current?

Only the MR CARTOOL B80, with a real-time voltage and current display. It shows battery voltage during replacement, detects circuit leaks, and measures vehicle quiescent current in the ignition-off state, per the listing. The other four picks state no display.

Which pick states a warranty?

The allsun GK504 states 1 Year. The Apopip spec table states OTHER, which is not a concrete term, and the MR CARTOOL, PUXWQT and OCHIKI listings state no warranty term.

Related: the best car battery memory saver guide, the best OBD2 memory saver guide, and the diagnostics and electrical hub.