This is an installation guide for the BennVenn NiMh module for Atari Lynx. The NiMh charge kit, which includes this module is available for purchase from our online shop. This guide assumes you have the module as part of the kit we sell. If you need to know how to take your Lynx apart, please check this article first - Lynx 2 disassembly steps and Screw size chart.
With the NiMh charge kit, you can charge NiMh AA batteries directly inside your Atari Lynx. This includes Eneloop batteries as well as cheap Varta NiMh rechargeable batteries. The batteries charge when a power adapter is plugged into the Lynx's power socket. You can also play and charge batteries at the same time. With this mod, you will never have to remove your NiMh cells from your Lynx, just charge them when you're done playing or as you play. There is a 10 hour timeout for charging, which is plenty for even the largest capacity cells.
The charge module has over voltage, over current, short circuit protection, 10hr safety timer, and an intelligent charge controller IC manufactured by Texas Instruments. LED charge indicators: Green = charging, Red = fault.
This mod will not restrict your console like lithium mods can. It'll work just as fine on a regular set of AA's as NiMh cells (Just don't try recharge non-rechargable batteries!)
Warning: For safety reasons do not leave your Lynx charging unattended.
Strip and tin the green, blue and yellow wires on each end. Then solder the wires to the contacts on the charge module - I (yellow) G (green) O (blue).
These diodes are SMD type but are fairly easy to remove, just heat one side and use a scalpel or screwdriver to lift that side slightly, then heat the other side and lift it too. Go back to the other side again, heat it up with the iron and it should come off. Clean up any remaining solder residue with some solder braid. Clean up any solder flux with IPA and cotton tip.
Here's an alternative way to desolder these diodes as shown by BennVenn...
Using the supplied length of metal pin, solder it across the D10 pads, then solder the green wire from the charge board to the pad closest to the wheel. On the D9 pads, solder the blue wire to the pad closest the capacitor, and yellow wire on the pad closest the wheel.
Below is a rough diagram of the circuit change.
The charge module comes with double sided tape on its back. Peel the protective plastic off the tape and secure the module to the RF shield of your Atari Lynx. This module can get quite hot (55C) when charging, so it's important to have it stuck to something that can dissipate that heat.
This is an optional step but if you have Kapton tape, you can tape the charge module down to the RF shield. This is in case the double sided tape comes loose with heat.
Now you can re-assemble your Lynx, put 6x AA NiMh batteries into its battery compartment and plug in a power adapter. The charge board has green and red LEDs on it. the green LED lights up to indicate that everything is OK. Once the Lynx is re-assembled, it should be possible to see the green LED through the gaps around the headphones socket.