Blown YUASA 14L-A2 battery. 17 mos old

Shortest life span battery I've ever had....
HOWVER:
I've noticed over the last year that I need to put water in the battery about every 5-6 weeks.
Charge voltage has been 14.5v for years but has been sneaking up on 15.5v this summer.
Been busy lately and forgot to check water.
Went out to ride and ....slow cranking, no start followed by a couple relay clicks and zing... nothing. And I mean NOTHING. Hardly the dimmest hint of neutral or oil pressure light.
At rest, no ignition switch ON, batter is 12.6vdc.
Ignition on, zoom drops to 5.5vdc
Push the starter button in.... drops to not quite 1.3vdc. Lol. Yeah 1 point 3 volts.
Pull the battery and it takes +7 ounces of distlled water to get to the lower fill line. Oh crap.
Hours on my regulated charger at 2.5amps, battery settles in at .4a after four or five hours.
Put it back in the bike ... all good but 8vdc with ignition on and nearly 2v with the starter button pushed. Damn it!! Looks like lovely me BLEW MY BATTERY with no water.
Buy new one, install it.... back to normal and instant start!
But, still 15.5vdc at 4500 rpm.
Ugh. Vintage bike ownership.
Guess I'm just bitcin'

Folks, if running a lead acid battery in these old cranks, check the damn water level in it once in a while...

I'll do that tomorrow. Notice they die when the weather turns.
Steve

Sounds like it may be time for a new voltage regulator or to adjust yours if it has that capability. I believe 15v should be the highest voltage coming through the regulator to the battery, so 15.5v may be pushing it a bit. The stock regulator on my 1977 KZ650 is adjustable, but I don't know if that was true for other 1977 models. Ed

Before I changed the regulator on my KZ900 I had to add water often - it would over-charge and boil the water out.

Yours may be charging too high, maybe not. I know on my KZ1000MKII when I took the long trips watering the battery was an every day thing. If I went two days without adding water the battery would be dry. I finally bought a maintenance free battery because digging the battery out every day to check is another waste of time on long trips I don't feel like doing.
And as to shortest battery life ever, I have ya beat there. 1993 E350 van, new Motorcraft battery lasted 12 miles and showed 0.000v. Man was that battery dead:-)

650ed wrote: Sounds like it may be time for a new voltage regulator or to adjust yours if it has that capability. I believe 15v should be the highest voltage coming through the regulator to the battery, so 15.5v may be pushing it a bit. The stock regulator on my 1977 KZ650 is adjustable, but I don't know if that was true for other 1977 models. Ed

IMine is the potted biscuit pan kind.

Those are notorious for overcharging. Get the R/R combo.
Steve

missionkz wrote:

650ed wrote: Sounds like it may be time for a new voltage regulator or to adjust yours if it has that capability. I believe 15v should be the highest voltage coming through the regulator to the battery, so 15.5v may be pushing it a bit. The stock regulator on my 1977 KZ650 is adjustable, but I don't know if that was true for other 1977 models. Ed

IMine is the potted biscuit pan kind.

Definitely different than the stock 1977 KZ650 regulator. Mine is like the one shown below. Ed

Of course there are better ones but I bought a used later model R/R and wired it in. Easy. I'll spend the $100+ later for a NEW good one.
Steve

It can also be the sense line to the regulator. Best to check that while running (revving) to make sure it really is the reg and not a voltage drop somewhere else.

swest wrote: Of course there are better ones but I bought a used later model R/R and wired it in. Easy. I'll spend the $100+ later for a NEW good one.
Steve

A Shindengen SH775 is about $75 and is the SERIES type, which means it will protect your stator from over charging heat. Shindengen is the OEM supplier for literally millions and millions of bike charging system R/R's going back to and before the KZ era.

If you have one of those funky single phase type charging system this info doesn't apply of course so please review as required.

Before I went to a modern regulator and rectifier I had to use two aftermarket regulators in my system to keep from boiling the battery and blowing out lights. I still have one attached but not hooked up. The stock rectifier burned up so I installed one from a 650 Yamaha 30 years ago. It is larger and worked well. The stock regulators were known to be junk and prone to fail.


This worked for a long time until I got the bike back up in 13. Got a used KZ 1000 R/R from the oldkawman and he sent me instructions how to hook it up. Very easy to do and I still have them if needed. The ones Ness is talking about hooks up the same way. I'll be buying one NEW soon. For the time being what I have works well enough.
Steve