Topic: So what kind of battery is everyone running? (CB750)

[ChopSticks]

On the tender, sure, it'll read 13v+, but the true test is a few hours after you remove it from the charger.
12.5 might not be enough to turn the starter, but you'd still be able to kick it over.
My scorpion reads 12.87v, 5 hours off the tender.

Yeah I just read that somewhere, I unplugged it before going to work I'll have to check again when I get home

So I retested it this morning and I got 12.40, then held it from there and it slowly stared going down 12.39, 12.38, 12.37. Even though the battery indicated said it was still good, I'm assuming it's probably a dud?

[flybox1]

IIWM, I'd spring for a new battery.

[ChopSticks]

IIWM, I'd spring for a new battery.

Yeah literally just put in the order for the scorpion AGM *crosses fingers*

Only if those lithium weren't so damn expensive 

[ofreen]

So I retested it this morning and I got 12.40, then held it from there and it slowly stared going down 12.39, 12.38, 12.37. Even though the battery indicated said it was still good, I'm assuming it's probably a dud?

You did the right thing getting another.  Based on whet you observed, if you put an actual load on that battery it would crap out.

[ChopSticks]

So I retested it this morning and I got 12.40, then held it from there and it slowly stared going down 12.39, 12.38, 12.37. Even though the battery indicated said it was still good, I'm assuming it's probably a dud?

You did the right thing getting another.  Based on whet you observed, if you put an actual load on that battery it would crap out.

Hopefully, it's just upsetting that the multimeter and battery tender both read it's a good battery. I wonder how they are programmed

[flybox1]

Your multimeter reads what your battery is putting out.  It cant say good or bad.  It only gives you a number.
YOU have to decide(w/ experience, common sense, etc) whether the value give is acceptable or not.
The tender, on the other hand, probably is set to read GOOD at any value over 12v.  What brand is it?

[ChopSticks]

Your multimeter reads what your battery is putting out.  It cant say good or bad.  It only gives you a number.
YOU have to decide(w/ experience, common sense, etc) whether the value give is acceptable or not.
The tender, on the other hand, probably is set to read GOOD at any value over 12v.  What brand is it?

It's the Deltran brand, but my multimeter has an actual function / additional light indicator that says if the battery is good, low, or bad 

[flybox1]

Only trust the numerical value your meter gives you...who knows what values the mfr set the meter at to go from low to good.   If that value was only 12v, then there is the issue. 
For the purposes of our bikes, 12.6 would be my min for good
If my meters GOOD light came on at any value below that, then i would ignore it.....

[Stev-o]

Hondaman posted this battery in another thread, thought I would throw it out there as I did not know Yuasa made a maint free version for the CB750

http://www.yuasabatteries.com/battery/ytx14ahl-bs/


Honda   750   CB750K Four   1969 - 1985   YTX14AHL-BS

*Note - it is approx 1/4" higher so a new band may be needed if you use one.

$75 shipped from Amazon...

https://www.amazon.com/Yuasa-YUAM62H4L-YTX14AHL-BS-Battery/dp/B0018F3MP6/ref=sr_1_1?dchild=1&keywords=yuasa+YTX14AHL-BS&pid=7WqXIGU&qid=1587133664&sr=1-1&vehicle=1974-59-17058-20-----14157------7&vehicleName=1974+Honda+CB750K

[Don R]

 My agm batteries from Advance auto are going strong. A couple of them are 4-5 years old. I maintain a couple times during winter on a good low output automatic charger.

[MauiK3]

I just went through the battery war. My slightly over a year old Scorpion AGM read 12.4 volts all day long but nothing worked. I started looking for some elusive wiring issue, turns out it actually was the battery.. Beat my brains out a bit.
Being out here on Maui we can’t get most batteries shipped so I went down to Napa Auto and got their sealed battery, fits great, we’ll see how long it lasts.

[PeWe]

My CB750's with stock charging systems have cheap sealed GEL batteries for less than half money than a Yuasa.

One small detail. My K6 with lightened alternator charge more from lower rpm than my K2 that has a stock late alternator.
K6 deliver +14V at around +3000 rpm.
K2 must run at least 4000, 4500 rpm.
Same max voltage around 14.4V.

Both have new batteries of same model and LED H4 head light.

The K6 with much less steel alternator should deliver less, but not.

I have a voltage meter to admire while riding. A late option for me and a must have