Modern Batteries

For some of the earliest MiniDisc portables, they used proprietary batteries. They are almost all guaranteed to be dead by now; no longer holding a charge, or chargers not detecting it at all.

Here we want to show you a (growing) list of modern replacements, and the units they belong to.

Sony MZ-1

The MZ-1 uses a NiMH BP-MZ1, these will no longer work.

There are a few modern equivalents. Both are 3D-printed shunts; they are basically just structural holders for 18650 cells.

First, is a two-piece shunt. For this you will need two 18650 cells, and some kind of conductive material (nickel metal strips, or copper tape) to get the power into the device.

Second is a one-piece shunt. Same general idea here; you will need to have some kind of conductive metal on one side of this.

Sony MZ-E20

The MZ-E20 is normally powered by AA cells, an AC adaptor or an optional Ni-MH battery pack BP-DM20 (Japanese original page) BP-DM20 (Google Translate version). This pack can be charged inside the unit with the AC adaptor. With standard rechargeable AA batteries inside the charge mode does not engage although it can be easily made to work.

Sony's original battery pack for this unit is the BP-DM20 which was made up of two AA cells and had a rating of 2.4V at 1.200mAh. Due to the pack going into a standard AA battery bay, the pack didn't implement the serial connection of the cells but rather only fixed them into a single package leaving the connection to the device hardware.

The pack's frame is basically just a simple piece of plastic and a sheet of metal wrapping the cells around this central piece. The cells were also glued fixed into this construction.

The key part of turning the cells into a chargeable package is a piece of the frame's plastic pushing a small switch inside the bay (on the in-device short end of the bay, located between the contact springs). Once this switch is engaged, pushing the player's stop button will activate the charger (twice to stop first and then charge or once to charge on an already stopped unit).

Replacing the aged and bad cells in an older pack with fresh 1.2V/1.200mAh ones is pretty straightforward. Gluing them into the holder is not requrired as the pack is held together pretty well with the metal wrapper.

It is advisable to only use cells with the above specs in order to operate within the originally designed parameters of the player's charging support. Also, inserting standard AA alkaline cells this way and engaging the charger is an absolute no-no!

Sony's actual AC adaptor to be used with the player would be the AC-E45HG. Similar adaptors such as the AC-E455F came with other 90s Sony hardware such as Discman devices. The two adaptors vary slightly in their specs (AC-E45HG: 4.5V/700mA, AC-E455F: 4.5V/500mA) but the lower rated one still seems to work fine and its charging current is still within the range of common Ni-MH wall chargers.

For people without an old battery pack frame at hand, not all is lost. One can prepare a short piece of plastic (for example from cutting a CD jewel case inner tray or an expired credit card), supporting it with the AA cell separator in the bay and simply fix it into place with a piece of tape. One should remember, though, that the safety mechanism against accidental charging attempts of incompatible batteries is now permanently overridden, requiring additional care from the user to be taken.

LIP series

Unfortunately, there aren't many modern replacements for these. You can take a chance with the 'remanufactured' or no-name replacements, but they are likely to be NOS (new-old stock; just sitting in a warehouse somewhere for a while).

If you have access to a 3D printer or 3D printing service, here are instructions for building a DIY LIP-4WM replacement (the battery used in the Sony MZ-RH1/MZ-M200).

There have been some attempts to do what is called 're-celling' some of the LIP units. This is *generally* a destructive process, even in the best DIY'ers hands. This involved separating the case halves from each other, desoldering the battery, and soldering in a new cell.

However, here is a less destructive tutorial on how to rebuild a LIP-12.

The LIP-12 series use plain 18650 cells, and the LIP-8 uses a 14650 or a more-common 14500 cell.

It can also be dangerous if you aren't careful, because these are lithium-ion batteries. If mishandled they will catch fire or explode.

The Sharp MD-MS200-S (and other similar models - see below) has one of those large, round Li-Ion 3.6V batteries (Sharp AD-MS10BT 3.6V/1400mAh) that look like a giant AA.

18650s are close and googling actually sent me down the path of custom vape/e-cigarette batteries. Most were close to the required size (70.7×19.7×19.7mm) and I was considering getting something with a shim or extra spring to make up for the 3-5mm that were typically missing in length.

The Streamlight SL-B26 is a 3.7V/2600mAh battery with a micro-USB (I know…) charging circuit built-into the top which gave it just enough length to get to 70mm exactly. Sure it wasn't a flat-top, but the measurement was correct. Not only that, it's a 2-pack!

They are a perfect fit! No extra pressure required to close the door, and there's no wiggle at all! That was just a test fit but my Sharp powered on and played showing 1 bar of battery.

I left them plugged into my multi-port USB charger w/2 micro-USB cables (the small status LED is nice) and came back in a few hours to test.

The good news - works perfectly! Very happy and again, I hope this is a good option for anyone looking for replacement MD batteries that have some kind of warranty (limited lifetime through Streamlight).

Bad news - find and use a lower output charger (< 500ma). I came back to find the tips of the batteries painfully hot! I removed them and let them cool while finding an old Plantronics charger (sub-500ma) that charged them while keeping them cool. A bit strange that the circuitry is drawing that much, but the Streamlight site talks about using their own charger for a full charge in 5 hours. Based on the capacity, 500ma is about right.

If you have a Sharp MD-MS200 (AKA Denon DMP-R70, Kenwood DMC-G7R, Pioneer PMD-R2 or these models which are also very similar, and I believe use the same battery: Sharp MD-MS100, Pioneer PMD-R1, Denon DMP-R50, Kenwood DMC-F5R) and need a battery, these Streamlight SL-B26 might be a good option!

Gumstick batteries

For the units that use the so-called gumstick batteries, this solution is easier.

There are several vendors that make these, and they do work.

Common brands are HQRP and Vapex.

(We use affiliate links to earn a small commission on purchases made using these links.)

With these there are no special handling or prep for getting them to work. Unfortunately the way NiMH batteries work is something you need to keep in mind when using them. They have what's called a memory effect.

But the long and short of it is, you need to complete a few charge/discharge cycles when you first get them to get their full capacity.

That's it. Your Minidisc portable that takes gumsticks? It works now!

NetMD units

Starting in late-2000/early-2001, NetMD units were released. A few of the first models continued to use gumstick or proprietary LiIon batteries.

But later, as technology improved, they started using standard AA alkaline batteries.

For many models, you can use modern rechargeable batteries (Eneloops and the like) to power these devices.


If you are using a new gumstick battery, sometimes it can be beneficial to add a bit of roughness to the positive end for better conductivity. This is not a standard thing for all batteries used in all units.

This might be helpful for a unit with corroded or physically damaged positive terminals (negative terminals are always inside the unit), or to test with.

Basically you take a nail file or emery board (preferably metal) and file a teensy bit of the top of the positive terminal. Just enough for you to see or feel a bit of texture to the top.

Standard AA

Some models will not like modern lithium batteries, like Energizer Lithium. The MZ-R37 is one that is a bit finicky. It will use standard alkaline AAs or Eneloop rechargeable batteries, but not lithium non-rechargeables.

Recording with rechargeable AA-Batteries

Players with only one AA-Battery (like the MZ-N510) abort recording very soon when not connected to an external power-source. This is because writing always needs the maximum-voltage of a rechargeable battery (around 1,3 V). If voltage drops to something lower, the device can't write anymore and will power-off. With a fully charged Ni-MH battery this will happen after 10 minutes already.

To fix the problem, manufacturers have created a rechargeable Li-Ion-Battery with special circuitry inside. It always outputs a constant voltage, regardless of charging-state. Amazingly, battery and circuitry fit inside an AA-housing. The capacity usually is between 1600 mAh and 2300 mAh. Charging is done externally with a micro-usb-cable.

Two important notes for usage:

Don't charge inside the player

Before connecting this special battery to a micro-usb-cable for charging, take it out of the device!

As soon as the cable is connected, the battery changes voltage from 1,5V to 4,5V. This will destroy your device, when connected during charge.

Disconnecting the cable, the battery will output 1,5V again.

Don't charge with the player

This is untested, but doing otherwise can't bring good results. In worst case the batterie's circuitry will switch to the internal Li-Ion-voltage during charge and destroy the player.

Li-Ion-batteries always have around 3 V minimum voltage, before the circuit cuts off the Li-Ion. So a reverse-current is possible when trying to charge the battery with the player at 1,5V.

Some example-batteries:

Fenix ARB-L14-1600U: Most expensive, highest average-voltage of 1,47 V, 1600 mAh only

Keeppower 1.5V Li-Ion P1450U2: Mid-range-price, 1,35 V average-output, 2600 mAh

Keeppower 1.5V Li-Ion P1450U1: Cheapest, 1,37 V average, 2000 mAh capacity

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