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Hacking Lenmar Mach 1 Speed Charger
Lenmar Mach 1 Speed Charger is a super fast battery charger that can charge your 7.2 and 7.4-volt Lithium-Ion battery packs quickly. But it's not all its good for. It's got an innovative design where each manufacturer's rechargeable battery pack interfaces to the charger via a different battery adapter plate (see picture below). My Lenmar Mach 1 Speed Charger came with adapter plates for Canon, JVC, Panasonic, and Sony battery packs. You can easily hack the adapter plate for various purposes.
Taking Apart the Lenmar Adapter Plates to Charge Different Batteries
I recently bought a Sony DCR-HC90 MiniDV Handycam. The camcorder uses the new slim A-series battery packs, such as the NP-FA50 and the NP-FA70. The A-series battery pack are a step away from the original standard M-series battery packs that came with all of Sony's previous generation camcorders. I happen to have a Sony DCR-TRV350 Digital8 Handycam, which uses the M-series battery packs, so I have several lying around. And I also have a Lenmar battery adapter plate for the M-series batteries.
Sony has also stopped supplying an independent battery charger with its camcorders. Instead, the Sony camcorders charges the battery packs on the camcorders themselves. This means that you can't leave a battery charging at home while out shooting video footage with your camcorder. Instead, Sony wants you to purchase independent battery chargers for your battery packs.
The Sony A-series battery packs contact pins are also a new design that is different from the M-series batteries. The M-series batteries accept round metal pins, while the A-series batteries accepts thin metal plates as shown in picture below.
It turned out that the Panasonic camcorders also uses the thin metal plate for interfacing. And I have a Lenmar battery adapter plate for the Panasonic batteries. Unfortunately, the separation distance between the positive and negative plates is different between the Panasonic and Sony batteries. But it did give me an idea, which is to take apart the adapter plate and detach the thin metal plates for use directly with the battery pack. Use a Phillip-head screwdriver on the bottom of the Panasonic adapter plate will reveal the thin metal contacts as shown in picture below.
Use a smaller Phillip-head screwdriver to detach the thin metal contacts from the adapter plate. Remember where the contacts goes if you ever want to put the adapter plate back together. Once the contacts are detached, you can manually insert each one into the Sony A-series battery as shown in picture below. Make sure you insert the contacts into the correct polarity slot. The polarity is indicated on the battery pack. Red wire is positive polarity. Black wire is negative polarity.
Alternative Method: Alligator Clips
An alternative to taking apart the adapter plate is to wire up a thin metal plate to an alligator clip for each polarity. Then clip the alligator clips to the contacts on the adapter plate. Insert the thin metal contacts on the other end of the alligator clip wire into the battery contact slots. Just be careful that the polarity are all correct when you insert the contacts.
I found the perfect parts for this project at the local RadioShack store. The part list below includes the Radio Shack part numbers in parenthesis.
The clips come in package of ten, much more than you'll ever need for this project. The smooth clip is perfect for insertion into the battery interface. The alligator clips are prefect for grabbing onto the Lenmar charging plates.
You'll need to solder the clips to the end of wires. Pair up each alligator clip with a smooth clip. Strip the wires and solder the clips to their ends. Remember that each wire should have an alligator clip at one end and a smooth clip at the other end.
Once you are done, you can connect the charger to the batter as shown in the picture below. The benefit of using the alligator clips is that you can basically charge the battery with any Lenmar charger plate that can be clipped to with the clips. In the picture, I was using a Canon BP-511 charging plate with the Sony A-series battery.
Note that, in the pictures, the clips are not insulated from another, so you have to be very careful of not shorting them out. I suggest insulating the clips with some black electrical tape.
Modify the Panasonic Plate for Smaller Panasonic Batteries
As technology advances, the bigger camcorder gave way to smaller and smaller camcorders. The VHS and Beta tapes gave way to 8mm tapes. The 8mm tapes gave way to MiniDV tapes and so on. In the progression toward smallness, the camcorder batteries also gave way to smaller and smaller batteries. Back in the 80's, camcorder batteries were huge like bricks. Today, they are small like little matchboxes. Just within the past two years, camcorder battery sizes have been reduced to half their original sizes, even though the underlying Li-ion battery technology hasn't changed.
Due to this constant change, the battery chargers obsoletes as well, even though they are fully capable of charging the newer smaller batteries. It's just that the physical battery form no longer fits on the chargers. Over the years, as I acquire more and more electronic gadgets, I acquire more and more chargers at the same time. The Lenmar Mach 1 Speed Charger is great at reducing the charging devices to one, through the adapter plates. However, the adapter plates obsolete as well and newer plates have to be acquired.
The Lenmar Mach 1 Speed Charger, I bought a few years ago, came with a Pansonic battery adapter plate (see picture below). It is capable of charging the Panasonic CGR-D120, CGR-D220, CGR-D08A, and CGR-D16A battery packs. It isn't made to adapt the Panasonic CGA-DU07 battery pack that came with my Panasonic PV-GS50S Digital Palmcorder MultiCam Camcorder. The CGA-DU07 battery pack is twice as short as the larger battery packs, therefore attachment hooks and tabs on located physically closer together. It wouldn't fit on the Panasonic adapter plate that I have.
Upon closer examination of the adapter plate and the battery pack, I noticed that the physical characteristic of the interface connector is exactly matching. They are the same on the different Panasonic battery packs. And in fact, the width of the CGA-DU07 battery pack is exactly the same as the larger Panasonic batteries. So, technically, the CGA-DU07 battery should slide onto the batter adapter plate just fine. The reason it doesn't is because the tabs on the battery adapter are in the way. So I used a sharp X-acto knife to cut the plastic tabs off the adapter plate (see picture below).
After cutting the two tabs off, the Panasonic CGA-DU07 battery pack fits perfectly on the Panasonic adapter plate (see picture below). Although the battery doesn't lock on the charger, without the tab, I don't see how a well-seated battery will come off from a charger that is sitting still on a flat surface. The Lenmar Mach 1 Speed Charger charges this battery just fine and very quickly. Now I can put another proprietary charger into storage.
Copyright © 2005 by Chieh Cheng. All Rights Reserved.