Waking up a Lithium Ion Battery

> Apparently with Lithium Ion batteries, if the voltage gets too low, the charger will not turn on (it will not sense the battery). There are tricks to "wake the battery up", which basically include bypassing the charging system and putting enough juice in the battery for the charger to recognize that the battery is low and needs charged. The charger kicks in and the battery is usually good as new.
>
> I have 2 Trimble Beacon on a Belt DGPS receivers that I recently acquired.
> They are both the same vintage. They have an internal Lithium Ion battery.
>
> I was able to get one of them to charge and it seems to be holding up well.
>
> The other unit will only power up on external power. The diagnostic software indicates that the battery is 100% full and not charging. However as soon as I unplug the unit, it is dead. I suspect that it has been left on and is completely dead.
>
> Does anybody know of a way to "wake" the battery up without sending it off to be serviced? I suspect once the charger kicks on, the battery will be fine.
>
> Thanks

It depends. If it's gotten too low (I think 1 volt per cell), then you're pretty much scuppered; there might be damage to the battery that could make it dangerous to charge.

The only "official" way I really know of is to get ahold of a charger with a wake-up feature.

If you're willing to give it a try, wrap it up with newspaper, tape it up, and stick it in a freezer for four days or so. Let it get back up to room temperature, and try to charge it again. The cold will temporarily reduce the maximum charge size, so if it's a battery with a relative discharge threshold, it'll let you charge it. Let it get fully charged before you try to use it.

I have tried this a few times, and had only one battery that it didn't work with. You might see a loss in overall battery life though. I have one battery that used to last a solid 7-8 hours, that now only gives me 6.5-7.

Thank you, after peeking inside the receiver, I could not figure out how to easily remove the battery without damaging something. Without guidance, I'm afraid I will break something I can't fix.

Perhaps the unit is designed to operate in freezing temperatures. I'll check and if it is, I'll give your freezer method a try and report back.

There is no telling how long this thing has been sitting with no charge.

Long shot (because I know nothing about this unit). Normal battery chargers, as I am told, will bring batteries from a low charge to full with no problem. Only the expensive chargers can bring a dead battery back to life unless you wire another battery parallel. Then the cheap battery charger recognizes a charge. Works on almost all flavors of batteries. So if you could get them out and just hook another battery with the same volts to the charger your in business. Testing the pins on the charger and making make shift charging station shouldn't break the bank. My buddy owns a battery store. I pick up little bits of information every now and then.

> Thank you, after peeking inside the receiver, I could not figure out how to easily remove the battery without damaging something. Without guidance, I'm afraid I will break something I can't fix.
>
> Perhaps the unit is designed to operate in freezing temperatures. I'll check and if it is, I'll give your freezer method a try and report back.
>
> There is no telling how long this thing has been sitting with no charge.

The datasheet for the Beacon Receiver states it has a storage temperature allowance of -40° F to +176° F. With a freezer set to 0°F, you're certainly no colder than many of the winter days I've had equipment out and operating.

Also, when taping your newspaper up, I found masking tape worked better than scotch tape.

I should have mentioned that the battery and charger is still enclosed in the unit.

I really wanted to take the battery out and simply order up a new one. I'm pretty handy doing those sorts of things. However I am at a loss as to what the next step would be to get at the battery.

I'm assuming at this point that the receiver comes out the top of the unit rather than the bottom. It appears that the receiver is suspended with the red rubber bands.

I thought maybe the top would unscrew or snap off, but it is solid.
My gut instinct is that there is an adhesive that softens with heat that holds the rest together. Any ideas? I'll stop short of damaging the unit and re-think my next step.

Trimble says it's a 12 volt system. Cut the red & black wires and hook up a small 12v in parallel and plug in charger at the port.

Or, take off the on/off switch and keep taking unit apart to find these internal batteries. Can't be that hard.

The red and black wires are the power going INTO the device's internal charger, which is not sending it to the battery.

The problem I'm having is figuring out how to get the insides out of the yellow casing without breaking it. After that it will be easy to get to the battery. Not exactly something you can find help with on the internet.

I appreciate your suggestions.

It's wrapped up in the newspaper and freezing now.