So, the application is a Hardley Dangerous Sportster, so might get moved to the American bikes section, but the topic is batteries,, And my weird issue.

So, application could be anything, But recently bought 3 batteries for projects, so anything that rolls on 2 wheels is applicable, Not that its a HD Sportie. (Year 2000 883 evo)

So my old AGM battery lasted about 5 years and I bet if I had been more diligent about battery tender and maint, I could have gotten longer, But excuses excuses, the last 2 years have been eventful!

So, a good AGM battery is not cheap,, good ones tend to be over $100 for my application, so rolled the dice on a eBay special good deal. See: https://www.ebay.com/itm/203037313209
" 12 Volt 20Ah YTX20L-BS GEL Power Sport Battery
Dimensions: 6.90" x 3.50" x 6.00" (L x W x H)

Cold Cranking Amps (CCA): 340A

Replaces: YTX20L-BS, YTX20HL-BS, GTX20LBS

Gel batteries are injected with Gel Electrolytes, creating a completely "maintenance- free" operation.

Batteries come fully charged and ready to use. Advanced design works right out of the box and requires no maintenance, yet offers the option to prolong the standard life by adding extra electrolytes.
These batteries are one of the most trusted and highest reviewed sealed lead acid batteries on the market. It's rugged construction is made up of non-conductive ABS plastic, which is resistant to shock, vibration, chemicals, and heat. It features AGM technology which allows the battery to be spill-proof and maintenance-free. Our batteries come with a 30 day worry-free return policy on all defective items, along with a one-year limited warranty! For inquiries, feel free to contact us. ​​​​​​​"

Sounds awesome right? I researched and thats excellent CCA of 340a for that size-class of battery. Good feedback and high volume seller, Even better,,, Price! $55.98 and free 3 day shipping! Such a deal!

So I installed it in late June, Did a bunch of other work, service and some cosmetics. 4 moderate rides and then I ended up leading a vintage club ride, took "Old Reliable" instead of one of my British bikes, But apparently the Sportie caught a virus/infection from the Prince of Darkness British bikes.

(Joseph A Lucas-A Gentleman does NOT motor about after dark!. The Prince of Insufficient light).

So, Ride was country roads, fairly brisk pace, 120 mikes of variable terrain, lots of bumps and a very firm suspension setting. (Shake rattle & roll!)

Towards the end climbing out of a canyon, My turn signals were intermittant, and Speedo on-off and flicker, same with lighting.

At a short rallypoint, There was nothing, I wiggled wires, pressed on terminals, But it bump started on a hill. Made it to the end. Died after Lunch at the Pub on my way home.

But it surged if I flicked between Hi-Low beams, and occasionally lights came on and starter turned over. Other times the lights & indicators on the dash would fade in and out like a bad connection. I figured I had a pinched wire, short, or bad connection. Tore it apart on roadside.. Could bump start and Idle but flub-flub-flub when revving it.

I pulled the headlight and tail lights and no change... A guy stopped and had a powerbox, and no change when jumping it. Again, figured I had bad grounds, or shorts.

At home, checked the voltage and had 13.58 volts across the battery, But wiggling wires,, No Ooomph and wouldnt turn over.

Tore it all apart, tested the regulator, grounds, terminals. Cant find anything wrong. Tried another battery... it starts and runs perfectly And good charging output well within factory manual specs.

Just checked it again, and top is see thru,, looks like all the acid is gone. Boiled dry? Again, Alternator and regulator are within specs. Another battery 12.78 at rest, at Idle flickers between 13. 75 to 14 volts and steady 14.25 to 14.50 volts at 2000 RPM with lights on.

Again, after I got home,,, it had 13.58 volts at rest, which is freakishly high, just checked it and cycles between 10.50 and 11.25 volts on my meter. My Smart charger freaks out and all the lights blink.

I emailed the seller, But I am inclined to pop off the top and add acid, and try charging, see what it does,. But I think the whole thing internally shorted out.

I CANT find anything wrong with the bike. Never saw such weird behavior. Anyone else experience this?

11.32 volts... Click image for larger version. 

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ID:	104741 Smart charger wigging out, cant get a read on that freaky battery... Click image for larger version. 

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