How many things have you taken apart just to look inside?
I’ve been doing that all my life, and maybe just like you… when I was a kid… I got a spanking for taking a few things apart that didn’t go back together right.
The Schumacher model SC1000A might make a good product to hack, but first, let’s figure out how to open it without breaking something, and we’ll look around.
If you look inside the handle, you’ll see two screws you can remove. Looking further, I didn’t see any warnings about voiding a warranty. I looked for the trick of opening the case without prying and breaking off tabs, etc.
As I ran my finger tip across the front panel, I found those tell tale holes that screws often hide in. I discovered the front panel cover (art work) is near magic. It is easily removed and stays sticky! Once removed, make sure you set this up where you don’t put something on top of it, I accidently put a piece of paper on it, and it stuck fast. I then put it under the kitchen faucet and let hot water help remove the paper, a little rubbing with a finger tip and it was all gone. I then flung as much water off as possible, and dried it under my desk lamp, and it was sticky and clean as new!
In those four holes, you’ll find small Philips head screws, easily removed. We’ll discuss those pieces of plastic later.. (no worries).
Just pull the light-colored plastic apart, and you’ll see how the end caps are sandwiched between.
Above you see the main board, There’s a few wires that connect this board to the front panel. As I look around, I give the mechanical guys an ‘A’ for this case design, it’s light, compact, rugged enough, and that handle is strong and flexes, it’ll likely hold up to my abuse.
About now, some might ask, why is it important that we get in here at all? My replay is, cords get old, they get cut, slammed in doors, chewed on by pets, and more. With this easy to access case, we can replace our cords if we need to.
Above is the most important reason to get into this case, and that is to replace this fan, and here is another reason for the ‘A’ grade, the fan is plugged into the main board with what looks like a standard pin plug found on a PC. The two screws holding the fan in place are again small Philips, and easy to get to. Many of these designs just quit charging all together if that fan quits, or they default to a very low charge, beware, if the fan isn’t running the unit is likely smart enough to shut down.
Here’s The very accessible front panel, the micro appears to be the EM784 20pin 8 bit micro using a masked ROM. When you plug this unit in, you can hear a high freq osc noise, unplug the front panel from the main board, and then plug the unit in and there’s no noise, so it’s likely the micro is the osc source. Unit draws approx 7 watts plugged in, no battery attached. The LEDS and the two switches used to pick battery type and charge rate. If you remember my mention above about those two pieces of plastic, if you remove this board, the ‘buttons’ you press, can fall out.. watch for them and make sure you put them back in before you put the front panel board back in place.
If you read my previous post about this product or a model quite similar, yes, this unit does need a battery with some juice in it to get started, but I found that to be no problem.
I reached into my desk drawer and pulled out a tiny 12 volt commonly found in a key chain transmitter, when I put it across the battery clips, the unit took off! I laid the battery down, and quickly tapped the battery clips together, sparks flew! It stays hot, it’s likely you can now put the leads across a dead battery and charge it.. Seems the designers use that little bit of voltage from the battery to prove polarity is correct.
So that story told by a reviewer that he sent he charger back because you can’t charge a dead battery?? well…. that wouldn’t have stopped a DIYer, and we know it’s going to be very rare when we find a battery so dead, and there’s an easy work around if we ever need to try and revive a totally dead one.
We have an easy work around already.. but there’s more, next, I put a single AA battery across the terminals; again with the correct polarity and again the unit came alive and I could feel the battery getting warm, as I pulled the battery clip away, the unit takes off fully with the fan running and the clips still hot and ready to be put across a battery.
Certainly, we have fooled the charger into starting and it is now our responsibility to get the polarity right, there may be other protection, but let’s not rely on that.
With this said, it’s my recommendation that you use some electrical tape to mount an AA battery to the handle with the ends exposed. If you ever have a reason to use the charger for a source of DC, or need to attempt to revive a dead as a door nail battery, just put the clips to the ends in the correct polarity, and this unit will take off.
The only thing I found this unit needs is your small effort to solder the connections between wires and clips, my HF power conversion Vector Brand unit got hot here when brand new, and the added voltage drop fooled the processor into giving up on the charging of a battery, it’s such an easy thing for you to do, and Murphy say it will be a problem if you don’t.
Compact, Light weight, rust proof, easy to get into, cords easily replaced, fan easily replaced.. I like it! This one is easy to take to your cabin. One more note, if you have a small generator NOT equipped with 12 volt charging, this is a potential solution.
one negative review found:
First, let me say that this charger performs flawlessly and deserves five stars
when it is in charging mode. I have used it for three years and hundreds of
successful charging cycles on a dozen different batteries of various sizes and
However, on two different occasions and with two different
batteries (both brand new when hooked to the charger) I left them in “trickle
charge” mode. The batteries were part of an emergency communications station
that must to be ready at any time with full batteries. This charger burned up
both batteries after three months of trickle charging. This mode is supposed to
allow a battery to be hooked up indefinitely and maintain it at peak
performance. Not destroy it. Other folks in the emergency communications service
use other chargers and leave them in trickle mode for years. DO NOT use this
charger for that kind of operation.
Suggested experiment, if you have a battery floating off an old style charger, plug in the KILL-A_WATT and study the power factor and total wattage draw.., it likely sucks, and you’ll find it is costing you far more than you knew to float that battery. If you have an inverter with a built in charger that uses AC to maintain the float, look at the power consumption, you may be amazed by the inefficiency of the charger WHEN in float mode. A custom DIY power supply based on this product may pay dividend in a shorter periodthan you expected.
With this stated, it would be fun to use an AVR or other programable micro to run this thing, perhaps, a programable float voltage where we simply disconnect charge until battery voltage drops below our threshold, and then we hook it up again? No need to put in panels or buttons, just a usb port in the side, and use your smart phone as a dumb terminal to set the parameters for floating the battery connected.
Perhaps, the better float plant will use a latchable relay on the AC power side, the micro in sleep mode most of the time, but wakes and checks battery voltage and then starts charger till float voltage is again at the cut off point.. the avr runs off the battery plant of course.
I see fun here, and there’s smaller and cheaper chargers from this company, I think I saw one for $31.00, you can’t buy surplus parts to play with for that price.
Another side note, this well known battery charger company has a warning sticker right on the back of this unit. “Replace worn cords immediately.” sounds like an invitation to open the case to me..