Saturday I went to start the motorcycle and found the battery dead. No click, no light, no nothing.

I was a bit peeved about it, as I keep it on a Battery Tender. So I removed the seat and tore into it, thinking the fuse had popped. Nope, fuse is good. A bit more digging led me to the "vthoky, you bonehead!" moment -- the negative lead from the tender wasn't connected. Not simply "not connected well," but straight-up not connected. Grrr.

I connected the lead to the battery terminal, plugged the tender in again, and figured I'd let the system do its thing for a couple of hours. When I went back to check on it, the tender still had its yellow "not charging" light blinking.

So now I'm at a loss and the questions come. Did the battery (Shorai LFX18A1) discharge so far that it won't take a charge? Is the tender just that -- a maintainer, not a charger? Will my old-school charger do the job, or do I need a special charger for lithium batteries (Shorai SHO-BMS01, for instance)? Have I ruined a $180 battery?

Aside from "vthoky, you're a bonehead," what guidance can you give? Thank you, SF.

Most likely, it's low enough that a "smart" charger won't recognize it as a chargeable battery.

When I run into that, I hook an old fashioned "dumb" charger up to it and get it up enough that the tender or smart charger will take over.

I'm not too savvy on lithium batteries, but I'd be wary of leaving it on a dumb charger very long. Just enough to get the voltage up a bit.

if you really discharged the thing to a fairly dead state, then yes, you should use the factory recommended charger to assure proper cell balance.

Interesting enough I haven't ridden in several months, hot, rain, etc.

Went out to move the behemoth, lo and behold dead battery, and the tender was connected, it just gave up after 4 years.

Took quite a while to find someone with a battery, they are in short supply, East Penn Deka has had no motorcycle batteries for 3 months! Finally found one at AutoZone...

Hook a good 12V battery up to your dead battery. Then charge using your maintainer. It will trick the "smart" electronics into thinking there is a battery there with enough volts to charge and begin charging. Once your lithium battery gets to 10 or 11 volts, you can disconnect the spare battery and charge as usual.

You have to trick these smart chargers into charging. Or find an old dumb charger that charges no matter what.

I really like these battery tender chargers. I have a bunch of them. On my rarely used truck, my motorcycle, my generators, my lawn tractors.

A small 12V lamp will trick it too. Just needs to be a low amperage draw or there won't be much left over for the battery with a tender.

One problem with the smart chargers is that they need a good ground. Don’t hook the black to the negative terminal hook it to some bare metal. If it’s an air cooled motorcycle then one of the cooling fins is a great spot otherwise it might take some looking to find some bare metal. You can try it on painted metal and you might get lucky if the paint is thin enough.

When lithium chargers first start charging, they charge for a short bit and then test if the battery has voltage. If the voltage is too low, it will stop charging, thinking the battery is faulty. I have had this happen with rechargeable tool batteries.

I once purchased a Milwaukee Fuel M18 drill off the Home Depot clearance end cap. It had been a demo, and had the battery permanently attached with a security lock. It was dead, dead, double dead. I bought it thinking that the drill was worth the $59 price. I took the dead battery home and placed it one a charger and received the blinking red fault light on the charger. Every time I walked past, I took the battery off and put it back on again, receiving the blinking red fault light. After about ten cycles of this, the charger went green and commenced to fully charge the battery. I'm still using that battery several years later.

Apparently every time the charger did its test, it charged the battery a little. With enough attempts, it had charged the battery just enough for it to pass a test, after which it went on the charge it fully. This is why PHPaul is saying to use a dumb charger, and give it just a small charge. It may rehabilitate the battery just enough to allow it to pass the smart charger's battery diagnosis test before charging it fully.

My 1977 XS650 always starts from the kick start, even with a dead battery.

quote:

Originally posted by bubbatime:
Hook a good 12V battery up to your dead battery.

I need some clarification, please. Connect the batteries plus-plus, minus-minus?

I do like the Battery Tender products -- we've got several of them in use. I won't fault this one at all --> the fault is all mine.

quote:

Originally posted by Krazeehorse:
A small 12V lamp will trick it too. Just needs to be a low amperage draw or there won't be much left over for the battery with a tender.

Put the lamp in series with the battery, with the tender leads connected to the battery? Or connect the lamp leads to the terminals, and the tender as normal?

quote:

Originally posted by sigcrazy7:
My 1977 XS650 always starts from the kick start, even with a dead battery.

Alas, there's no kick starter on the VFR800.

VFR 800…The best motorcycle ever, (IMHO)!

Traditional smart Battery tenders need to see some voltage to start. You can get it any number of ways. Hook up anything with actual voltage (I've used everything from another 12v battery to a 9v cell) plus to plus minus to minus so that the tender sees a positive voltage and it will start.
The best possible ground is the battery terminal so don't make that worse. I have no clue what the person with the 12v lamp is talking about. It won't do anything to start the charger.

Lithium batteries are a whole different game in charging and you realistically need a charger intended for lithium batteries and you may very well need a mfg approved charger to get the cells correctly balanced on a battery you have discharged completely. In your case I'd start with a good lithium charger and see where you go assuming that you would replace the battery with a lithium one if its truly shot and the charger you will need anyway.

quote:

Originally posted by Wayniac:
VFR 800…The best motorcycle ever, (IMHO)!

Just clip the test light to the battery terminals like you were testing the battery. Then it will draw on the charger to make it light and that voltage is also being applied to your battery terminals.

i have no clue what kind of chargers you think this will affect. the smart ones want to see a voltage above a certain point before they will start. you can add any load you want across them and it won’t matter a hoot. this feature means that banging the terminals together has no possibility of current flow. it also
means what you describe won’t do squat.

quote:

Originally posted by Krazeehorse:
Just clip the test light to the battery terminals like you were testing the battery. Then it will draw on the charger to make it light and that voltage is also being applied to your battery terminals.

That wont work on any smart chargers I know of. They check for voltage before they start charging and just placing a 12v test light on a zero voltage battery, will still have zero voltage, and thus, the charger will not kick on.

quote:

Originally posted by vthoky:

quote:

Originally posted by bubbatime:
Hook a good 12V battery up to your dead battery.

I need some clarification, please. Connect the batteries plus-plus, minus-minus?

Just like you are jump starting a car. Positive to positive, negative to negative. Once the jumper cable is there, your battery will show 12V thanks to the good battery, and then your charger can kick in.

Slight thread drift…I’m of the opinion that most motorcycle batteries are too small for what is expected of them.
Yeah, I know, size and weight constraints and all that.
And their life varies from (motorcycle) brand to brand.
My Honda (2012 NC700) will keep a battery for three years, usually.
The Harley (2016 Roadster) two years max, and maybe every spring, whether ridden in the winter or not.
And both of these bikes stay in the shop portion of my barndominium.
And no, I don’t normally keep them on a tender. They get ridden at least weekly as I mainly use them to commute to work and run light errands all year.
It just seems we could engineer something better than that.
Now, about those tires…..

After tricking the charger to start working it should activate and charge the battery. I know that when traditional lead acid batteries get low on charge they begin sulfating which weakens the battery so even brought back up to charge they then loose charge again. But I'm not sure lithium batters suffer the same result?
Battery Tender offers a charger that charges both traditional and lithium, you just have to remember to switch it to the correct one. It wasn't very much, maybe $60, I bought it because my Africa Twin comes with a lithium battery.

I'd suggest putting your bikes on a Tender hudr. You don't have to keep them hooked to one, in fact I feel that's a bad idea, but most of the time after we park our bike the battery isn't fully charged and the parasitic draw from the bikes ECM, clock, alarm, etc begins depleting it down from there. And even a slightly discharged battery will sulfate faster than one fully charged. The reason they're often not fully charged when we park them is because, unlike cars, at idle and even lower RPM motorcycle alternators don't keep up with demand so the battery is discharging.
Even after a brisk run most people ride their bikes slowly through town or their neighborhood, up the driveway, might even let it idle while they get off to open the garage, and all this time it's loosing a bit of charge. My Airhead BMW is particularly bad in that as it's only charging more than it uses to run when over 3,000 RPM.
I shift my chargers from bike to bike and anytime it's connected to the bike last ridden it lights red and has to charge a little while to top it up. When connected to a bike that hasn't been ridden, but briefly connected to a charger every couple weeks, the charger typically switches to green (float mode) within 5-10 seconds. Anyway this has worked for me for instance the battery in my Harley is 4 years old this year, I was planning on replacing it this Spring but it tested out fine. I imagine it'll be weak next year.
For any who do use Tenders I would advise to not leave them connected, unplug to go for a ride then connect back up when when back, because a weak battery just off a charger will be topped up and start the bike fine. But after riding then stopping, say for gas, it could be too weak to start. Don't ask how I learned this.