I never got a second battery tender, so the Yuasa AGM in my ST2 completely discharged over the winter. I've had it hooked up to my Battery Tender Jr. for a week or so, which is still flashing the 'Charging' LED.  I went to run it over a few days ago and didn't even get a click. Still totally dead.

Are there any tricks to revive it, or is it shot?

The battery is only a few years old and was always on the tender up until this last winter.

TIA

https://www.optimabatteries.com/en-us/support/charging/resuscitate-deeply-discharged-battery

Quote from: Buhgaboo on June 15, 2019, 09:25:06 AM
https://www.optimabatteries.com/en-us/support/charging/resuscitate-deeply-discharged-battery

I was just going to post this! Lol

There is a possibility of bringing that battery back to life with that charger.  Probably won't live much longer though.  Me, I would put that money into a new battery.

I just went through the same thing with the battery on my XR... even AGM batteries finally give it up.  I went ahead and replaced it, and the OEM battery in the Monster... it is 5+ years old and getting weak anyway.

Thanks for the replies, I appreciate it.

Any recommendations for an inexpensive true charger? Seems most I come across are similar to the tender that I have, which is unable to charge from dead. I'm not sure how tell what can charge from dead.

I figure I'll try reviving this one and see how it goes.

You can buy something like this   https://www.amazon.com/Schumacher-SC1279-12V-Rapid-Charger/dp/B07DM22XTN/ref=sr_1_14?qid=1560790915&refinements=p_89%3ASchumacher&s=automotive&sr=1-14  You want one with a maximum charging rate of 10 amps or less.

An alternative technique is run a battery with some charge in parallel with yours and charge both.  As soon as your battery has some charge just charge yours by itself.  This would take a long time, a little more than 13 hours with a Jr. or about 8 with a Plus.


Your Tender should be able to eventually charge a stone dead battery unless the battery is defective or the battery is installed in the bike and there is a notable drain on the battery.  What are the lights on the Tender doing?   Do keep in mind a battery that has been sitting in an undercharged state for a long period of time will have suffered from sulfation, the reason for my earlier reply.

Quote from: howie on June 17, 2019, 10:30:29 AM
You can buy something like this   https://www.amazon.com/Schumacher-SC1279-12V-Rapid-Charger/dp/B07DM22XTN/ref=sr_1_14?qid=1560790915&refinements=p_89%3ASchumacher&s=automotive&sr=1-14  You want one with a maximum charging rate of 10 amps or less.

An alternative technique is run a battery with some charge in parallel with yours and charge both.  As soon as your battery has some charge just charge yours by itself.  This would take a long time, a little more than 13 hours with a Jr. or about 8 with a Plus.

Your Tender should be able to eventually charge a stone dead battery unless the battery is defective or the battery is installed in the bike and there is a notable drain on the battery.  What are the lights on the Tender doing?   Do keep in mind a battery that has been sitting in an undercharged state for a long period of time will have suffered from sulfation, the reason for my earlier reply.

Thanks, Howie.

I'm assuming the battery is probably toast, though I wanted to at least attempt to revive it.

The Tender (it's a Plus, not a Junior --sorry), is flashing red, which indicates the tender is working but not charging. Which means it detects < 3 volts from the battery.  I'm not sure if the Schumacher unit will overcome this low voltage or not.

Quote from: d3vi@nt on June 17, 2019, 01:09:25 PM
Thanks, Howie.

I'm assuming the battery is probably toast, though I wanted to at least attempt to revive it.

The Tender (it's a Plus, not a Junior --sorry), is flashing red, which indicates the tender is working but not charging. Which means it detects < 3 volts from the battery.  I'm not sure if the Schumacher unit will overcome this low voltage or not.

I've read mixed reviews on the Schumacher units regarding charging completely dead batteries. You can always hook two batteries together in parallel, one good and the bad unit, to get the bad unit above the no charge threshold. I'm looking at a new Schumacher unit for using around the place for multiple sizes of batteries.

I'm looking at this one... https://smile.amazon.com/gp/product/B07895QQBN/ref=ox_sc_act_title_1?smid=ATVPDKIKX0DER&psc=1

I have one very similar to the one Ducpainter tagged.  Mine is a bit older, so it's not fully automatic... I get to choose the charge rate (2a, 5a, 10a) and what kind of battery it is, which I like.  I don't believe it has a 'maintainer' function, but it may.  I use my Yuasa tender for that purpose, anyway.

FWIW, I had my XR battery on the big charger for 24 hours and it never picked up a charge... it's just dead.  Unless you like to push start your motorcycle when you are out somewhere... I would just pull the plug and get a new battery.

Quote from: Charlie98 on June 17, 2019, 06:21:03 PM
I have one very similar to the one Ducpainter tagged.  Mine is a bit older, so it's not fully automatic... I get to choose the charge rate (2a, 5a, 10a) and what kind of battery it is, which I like.  I don't believe it has a 'maintainer' function, but it may.  I use my Yuasa tender for that purpose, anyway.

FWIW, I had my XR battery on the big charger for 24 hours and it never picked up a charge... it's just dead.  Unless you like to push start your motorcycle when you are out somewhere... I would just pull the plug and get a new battery.

Even on the 'fully automatic' models the user has to choose the battery type, and max charge rate. If nothing is chosen in 10 minutes it will default to AGM type and a slow charge. I chose this model because my tractor has a 100+ amp Group 31 battery, a car/pickup, and my trailer has a large deep cycle house battery where tenders just don't cut it.

I have to get something for my SS that has a Lithium battery, also.

(edited for spelling)

I couldn't tell from the picture if it had buttons like mine.  Your's is all swoopy and aerodynamic... mine is just a black box.   

Quote from: Charlie98 on June 18, 2019, 07:56:17 PM
I couldn't tell from the picture if it had buttons like mine.  Your's is all swoopy and aerodynamic... mine is just a black box.   

It makes me wonder if they spent more on the case, and hidden switches, than the internals.

They have one at work like that. I used to have one that was kind of pewter and white. It was a great charger, although not very high amperage. It had a switch for 6 or 12V...that's it.

Shopmate's multi-purpose charger:





My hella old charger and recent load-tester:

https://www.ballistic-batteries.com/

Defunct...