Resurrecting Lithium Batteries

[koko64]

I have a method of bringing what appear to be terminally flat Lithium Iron batteries back to a servicable state. I have only done this with Shorai batteries when they are out of warranty. The warranty is good as far electrical components are concerned and the dealer in your part of the world probably has special equipment to do this. I'm waiting on a very busy mate of mine to build a custom resurrection charger. I've found that if this method doesn't bring 'em back then they're buggered.

I use three chargers to do this; an Optimate (TecMate) Li Smart charger, Shorai's specific diagnostic/maintenance charger and a good old fashioned Arlec 4 amp lead acid battery charger or equivalent. A multi meter is also needed as you need to check your voltages.

When a Shorai is way over discharged the Shorai charger has a hissy fit and will not charge it. You may be able to convince the charger to commence charging by continually pressing the charge button every time the charger's over discharge alarm sounds.  If it starts the charging proceedure after a few attempts then your battery wasn't too bad.
The problem is when the Shorai charger cant get going becauae it's thrown by the level of over discharge beyond it's parameters. Enter the Optima charger with it's multi stage system that also has a "Save" function that may kick in after it performs its diagnostic. If this works and the charger does its thing your battery was pretty bad but not too bad. A problem could be that the battery may only charge up to the low side of full showing a reduced capacity, but if you're lucky you might get a good 14+ V.
If the battery is now holding 13.5+ V then the Shorai charger should be able to take over and finish the job.

If the battery appears to not take over 14V no matter how many attempts with these chargers then it's time to get serious, and potentially dangerous.

SAFETY WARNING!
Don't do this at home kids.
If you have even less electrical knowledge than myself then forget it.
If you blow up the battery, burn down your house or get liquid Lithium lava fire on your balls you're on your own.
If you are likely to electrocute yourself then this isn't for you.
If Nate thinks this thread is too risky he can delete it as I dont want to be sued by some knob that has burnt his balls off.
You've been warned.

If you have found a device that does this safely and automatically then use it as my process is annoying and prone to human error. I believe the national distributors will have such a device to fully diagnose, charge and revitalize these batteries under warranty.

I hook up the voltmeter and connect my car charger + to the battery +,  holding the - over the - battery teminal. I can monitor the voltage as I touch the chargers - clamp to the - termial and watch the voltmeter. As the voltage climbs to 14.5-14.8V I release/ remove contact with terminal so that I never exceed 14.5-14.8 V. It may take awhile for the voltage to climb but it can suddenly accelerate at the last second, so don't think its safe to get a coffee if the voltage is climbing slowly. The rate of voltage can suddenly run away from you and then it won't be coffee you are smelling! The Shorai battery has a warning to never exceed 14.8 V and the instructions in the box mention 15V.  I touch the - charger clamp to the - terminal repeatedly until the the voltmeter indicates that the battery is building up to taking the full allowable voltage.  Use 14.4-14.8 for a safe margin. Over charging  can kill the battery and possibly cause a safety issue. I do this process on a concrete driveway away from flammables with a fire extinguisher handy. KEEP AN EYE ON YOUR VOLTMETER.

What this manual deep charging process is doing is stretching the battery capacity back towards what it originally was. The nasty old fashioned charger hammers the Lithium battery pretty hard and some have been lucky using them without killing the battery via overcharging or causing it to melt or burn. The problem is that without an accurate voltmeter monitoring the process people have had no idea what is going into the battery.
What I am doing is manually intervening every time the voltmeter hits 14.5-14.8V by disonnecting the charger cable for a few seconds then touching it to the terminal until I see voltage start to hang around the 14+V mark. This is when the Shorai charger can take over to balance charge the battery and finish the job.
This process is stretching the battery capacity back to shape. Iirc Speeddog found a charger in the States that may do this. Me mate down here will build me a custom version that times and sets the voltage so I dont have to waste time manually controlling and monitoring voltage.

The battery once having been brought back from the brink may be "servicable",  but with less capacity and a slight loss of CCA.  They're never quite the same, but can still provide good service considerably extending their service life. I have no idea if this process compromises their overall safety while in operation, so if in doubt, buy a new one. If still in warranty then send it to the dealer for diagnosis and possible "repair" or replacement.

I welcome comments from those expert in electrickery who may be able to provide a theoretical background to my observations and practical  findings.

[booger]

TecMate/Optimate Lithium charger is supposed to do all of that. No need for three chargers & all that rigamarole. Set it ->forget it. Takes a while but you don't actually have to do anything but wait for it to do its thing.

[EEL]

Very detailed report.

Have you ever tried just tying the positive and negative terminals on a good donor battery in parallel with a depleted to allow for more of a balancing charge to trickle between a good battery and a bad one? Essentially connect the positive terminals together and the negative terminals together. This is essentially what you do when you're jumpstarting a car.

I've done this to recover standard batteries all the time and never had any issues. Usually if you do it betwee a car battery and a lithium moto battery, the capacity of the car battery is large enough to not really drain down to damage a fully charged. It also has a benefit of not overcharging because both batteries will balance to an equilibrium voltage.

Every time I've recovered batteries its only been because I didn't have a substitute readily available. They tend to never recover enough to remain functional for a long time.

That's probably why the shorai charger doesnt even bother. It is not the best PR if your batteries leave you stranded on the side of the road. This is the drawback of lithium since their Amp Hour storage is usually lower than a lead acid (mostly done to keep the price competitive with cheaper lead acid counterparts)

[koko64]

TecMate/Optimate Lithium charger is supposed to do all of that. No need for three chargers & all that rigamarole. Set it ->forget it. Takes a while but you don't actually have to do anything but wait for it to do its thing.

Actually thats the one I have. I'll correct my error from Optima to Optimate. My error. It hasn't worked quite as well as I hoped. It's good, but maybe I should persist with it


...

Very detailed report.

Have you ever tried just tying the positive and negative terminals on a good donor battery in parallel with a depleted to allow for more of a balancing charge to trickle between a good battery and a bad one? Essentially connect the positive terminals together and the negative terminals together. This is essentially what you do when you're jumpstarting a car.

I've done this to recover standard batteries all the time and never had any issues. Usually if you do it betwee a car battery and a lithium moto battery, the capacity of the car battery is large enough to not really drain down to damage a fully charged. It also has a benefit of not overcharging because both batteries will balance to an equilibrium voltage.

Every time I've recovered batteries its only been because I didn't have a substitute readily available. They tend to never recover enough to remain functional for a long time.

That's probably why the shorai charger doesnt even bother. It is not the best PR if your batteries leave you stranded on the side of the road. This is the drawback of lithium since their Amp Hour storage is usually lower than a lead acid (mostly done to keep the price competitive with cheaper lead acid counterparts)

I will give that a shot as an option. I hadn't considered it with a Lithium battery.
Appreciate the responses fellas.

[EEL]

Just remember, this is just to "ressurect" lithium batteries. Most lithiums tend to run slightly higher voltages than their lead acid counterparts.

So if the voltage is sufficiently low, this option may get you back to new 12 - 12.6 volts on a lithium. Perhaps enough to get a standard lithium balance charger to take it the rest of the way instead of just crapping out.

Best thing to do is to compare voltages before connecting both batteries together. If your shorai is already a higher voltage than the lead acid, you may be going the wrong way.

[koko64]

It's definiately all about getting the batteries to a point where the Li specific charger can take over without protest.
Maybe I gotta learn to better drive the Optimate charger? What's great is my buddy can build me whatever I want (when he has time).
It certainly helps to think of Lithium batteries as 13V batteries.