'80 KZ650 Battery Change

Hi, I recently (about 2 months ago) bought my first bike and have been getting a lot of good info from these forums.
This is my first post and my current issue I saw something similar to but not the exact information I require.
Last weekend my Lead-Acid battery died permanently after I took it to O'reilly's for a charge, so I opted to get a Lithium battery since it is less maintenance.
I bought an AG-801 Antigravity Battery but on the caution label it mentions that any/most pre-1990 Voltage Regulators should be updated before installing the battery to prevent risk of fire. Does anyone know a good/reliable KZ650 compatible RR or know how to check if the stock RR is suitable?

It also mentions on the label that RRs over 28 years old can cause a fire due to Over-Charging and I am curious if that has happened to anyone in the past. I would prefer to maintain and not burn out my bike the best I can.

It needs to be a "MOSFET" R/R for a lithium battery and install a 30amp fuse between the R/R and the battery on the main output (lithium battery fires are no joke !!!)

Lithium batteries and old motorcycles are like oil and water.  They don't mix.  As I understand it, Li batteries must be charged at a lower voltage; 14.0 VDC max.  You will need a special LI R/R that caps charge voltage, and they are NOT cheap.  Rick's sells them.  

My opinion, you would be miles ahead by using an AMG battery, and buy a SERIES type R/R like a Shindengen SH775.  A series R/R will protect your stator from overheat damage, and AMG batteries are tried and true.

Nessism wrote:

Lithium batteries and old motorcycles are like oil and water.  They don't mix.  As I understand it, Li batteries must be charged at a lower voltage; 14.0 VDC max.  You will need a special LI R/R that caps charge voltage, and they are NOT cheap.  Rick's sells them.  

My opinion, you would be miles ahead by using an AMG battery, and buy a SERIES type R/R like a Shindengen SH775.  A series R/R will protect your stator from overheat damage, and AMG batteries are tried and true.

I don't disagree Ed, lithium doesn't necc need a smaller voltage but it does need a stable output around 14.2v - 14.4v hence the need for a MOSFET R/R which gives that linear output. However given the safety issues associated with Lithium batteries I would only recommend where space is an issue (like my build where it needs to lie flat in the tailpiece and the ultrabat is smaller than a conventional battery) if you are using the stock battery location I would advise AGM every time

My only issue with AGM is the sizing doesnt match as they tend to be half an inch wider than the lead acid battery, but if I can find one that fits appropriately I may return the Lithium battery and purchase AGM instead.
As for returning the the stock Lead-Acid method, they are pretty cheap, I am just concerned I may have a charge issue.
Thanks again btw! Lots of helpful info here

RCNFL wrote:

My only issue with AGM is the sizing doesnt match as they tend to be half an inch wider than the lead acid battery, but if I can find one that fits appropriately I may return the Lithium battery and purchase AGM instead.
As for returning the the stock Lead-Acid method, they are pretty cheap, I am just concerned I may have a charge issue.
Thanks again btw! Lots of helpful info here

You won't have a charging issue if you get a SH775.  And no counterfeit  SH775's allowed.  

OK, I own a motorcycle not that old, a 1991 Zephyr 750.    Have also installed voltage indicator on dash.   Factory R/R would fluctuate wildly, sometimes going to almost 15VDC while riding.    I changed the R/R to a Shindengen SH755 for this very same reason of running lithium battery.

The Shindengen SH755 keeps the voltage within 0.3VDC around 14VDC.    Have been using a Lithium battery for about 2 years now and have had no issue whatsoever.   .....and it is amazing how light the Lithium battery is.  

I use a LiFePo battery (with an integrated load balancer) in my Z1 since 2018, never had any problems with the stock R/R hardware.
LiFePo batterys s don´t go rocket like Boom like pure lithium batterys.

I'd probably stick to a flooded lead acid or AGM unless you have some tight packaging situation.
Charging systems aren't that hard to figure out. I would find out what is wrong with your system first.
My opinion is lithium ion is too unpredictable for a motorcycle that may get parked in a garage.

From the Ducati forum a couple of weeks ago.
This was a lithium iron phosphate battery fire...not a lithium ion (lithium ion has a much higher energy density per kg or lb).
Lithium iron phosphate is usually safer.
www.ducati.ms/threads/close-call-at-the-shop.753310/#replies
 

My only issue with AGM is the sizing doesn't match as they tend to be half an inch wider than the lead acid battery.

What model is it?  Did you get the correct battery for your motorcycle?  In the past I've gotten a Scorpion AGM from batterystuff.com and the size was correct for my 1981 KZ650-CSR. The dimensions listed there are the same as the Yuasa site.  same thing for the battery listed for the 1980 KZ650s. note: the sites mentioned don't list the 650F but partzilla indicates that it has the same battery as the Ltd and Custom.

My model is a KZ650-F1. I ended up purchasing another Lead-Acid and I got it charged up and the bike ran good for a while, even fixed another minor issue on its own with the speedo not reading past 35MPH.
Unfortunately though the bike died again, kickstart cant turn her over, push stary gets some rumbling but no ignition and I tried to short-start the starter solenoid which only sparked a bit and the lights stay on so I think my battery troubles are solved for now.
Also replaced the starter solenoid just incase, still no start so I am on to the sparkplugs.
I will keep the model AGM in mind that you have if I have to replace the battery again (somewhere in the ignition system something went wrong but the lights seem to be fine)

Do you have a voltage tester?  I use a VC-97 digital multimeter and keep my battery charged w a Ctek US 0.8 smart charger. You almost have to have both for an old motorcycle.