Battery Life

[TripleKing]

How long does the battery usually last in your Kat. In my 89 750, they tend to last about two seasons before showing signs of weakness. The drop-off comes rather sudden too. I had a conventional battery go belly-up after two years. Now have a sealed battery showing signs of weakening at about the 21 month mark. I use a battery tender to keep it fresh, particularly over the winter. Also, it seems that the Kat will only crank fast enough to start when the battery is in top condition. Lastly, my tenders cannot seem to get my battery to maximum charge, but my big charger can, using 2 amp trickle). The battery will usually holds enough charge to crank the engine strongly for about 24 hours. After that it drops off. Interestingly, I notice no difference in cranking performance if the battery is left off the charger or not started for 48 hours or for a week. If the Kat is ridden daily, there is not problem whatsoever. However, with five bikes and the Kat no longer the commuter, this almost never happens.

[92xjunker]

I use a lithium battery, they last much longer.

[ZookRick]

Leaving a battery on a tender for a long time is not a good idea. Best thing to do if it is cold out in the winter is bring it inside to keep it warm. (Cells can freeze if the charge is low) Periodic checks of voltage to make sure its ok, and a short amount of time at 2 amp if its low voltage, then back off the charger.
I am on the same AGM battery for 4-5 years now.

[92xjunker]

That is true, I put my lithium battery in the fridge during the hot summers, they don't like heat.

[TripleKing]

Leaving a battery on a tender for a long time is not a good idea. Best thing to do if it is cold out in the winter is bring it inside to keep it warm. (Cells can freeze if the charge is low) Periodic checks of voltage to make sure its ok, and a short amount of time at 2 amp if its low voltage, then back off the charger.
I am on the same AGM battery for 4-5 years now.

I would alternate the charger a few days on each of my five bikes

[RobertTravis]

The problem with the stock-type Yuasa wet batteries is that it doesn't take much for the electrolyte to evaporate...I've had them go down to 1/2 way in only 2 or 3 months, only to have to top them off to get back to full amps.

Car batteries used to be like this...before the late 70s when 'Maintenance Free' was a huge deal.

I went through the same thing with my KLR650 and finally bought an AGM sealed battery for around the same price as the stock wet type.

It seems to last longer just sitting (all winter no charger - because I was too lazy to unbolt the plastics) - so I'm pretty happy with it.

I'll either go lithium or AGM for the Kat 1100 when it is time.

[Kreylyn]

The Lithium Iron batteries are amazing. I've had one for 2+ years now, minimal tender use, long periods of sit... and the bike starts right up every time.

That said... if your bike is seeing hard starts off the battery in a very short time, it may also be less of a battery issue, and more of a low voltage to the coils issue caused by dirty/poor electrical connections of the wiring harness.

If the bike does not get 11v at the coils, it wont' start well if at all.

I'd suggest you check the coil voltage vs the battery voltage with key off, key on, and starter turning the motor over (that should give you 6 numbers to compare by) and see if there is a major difference between numbers.

Krey

[TripleKing]

It isn't a coil issue. It is a cranking issue. When I charge the battery with my big charger (on 2 amp trickle), the engine cranks strongly and fires right up (after fiddling with the choke). I went to crank the Kat early this afternoon and it cranked slowly. I attached my batter charger and it read that the battery was about 85%. It never reads below 80%, even after a week or more, and the battery maintainers never get it above that. My big charger will get it to 100% and she will fire right up.

I charged battery, started the bike and let it idle. Here is what I found.

After charging, the battery read about 13.5 volts on my voltmeter. When running, my volmeter (old analog meter), read just under 16 volts. Shut off the bike and let it sit for 15 minutes and it read 13.5 volts. Letting it sit for a longer period and will check again.

The problem with the stock-type Yuasa wet batteries is that it doesn't take much for the electrolyte to evaporate...I've had them go down to 1/2 way in only 2 or 3 months, only to have to top them off to get back to full amps.

Car batteries used to be like this...before the late 70s when 'Maintenance Free' was a huge deal.

I went through the same thing with my KLR650 and finally bought an AGM sealed battery for around the same price as the stock wet type.

It seems to last longer just sitting (all winter no charger - because I was too lazy to unbolt the plastics) - so I'm pretty happy with it.

I'll either go lithium or AGM for the Kat 1100 when it is time.

Mine is an AGM battery

[92xjunker]

16v is too high!! Might want to check on that while you're at it. What is your amp draw while the bike is off?

[TripleKing]

It was closer to 15.

Left for about an hour. Came back and the battery read just over 13 volts. Started it an observed that the draw did not bring the volts below 10. It fired right up. When running, volts hung in the mid 13s until I blipped the throttle. At that point the volts ran up above 15 then settled between 14 and 15. I started it several more times with the same results. I will check again tomorrow. I want to see how it is after 24 hours.

Remember, I am using an old analog meter. Reading the exact number is not easy.

[RobertTravis]

You might want to get a digital meter...they are cheap. Starting @ $12 delivered

The difference between 13.8v and just under 15v is important...and finding out which one is the right number is the difference between smoking expensive parts on the bike and normal operation.

[TripleKing]

My son has one, I should be able to borrow it tomorrow.

[TripleKing]

OK, son was a no show, but in my old analog gauge, the battery read 12.9 volts after sitting for 18 hours. When I cranked the engine, voltage dropped bounced between 8 and 9 volts. This has me thinking the battery is toast. After I stopped cranking, the meter read 12.5 volts, then 12.6 volts, then 12.7 volts. I then observed the gauge, occasionally bounce between 12.7 volts and 12.4 volts, before settling again at 12.6 volts, where she sits right now. I will check again, in a little while, but I know the answer is a new battery.

FYI: At 12.9 volts, the engine cranked slowing, even pausing cranking, temporarily (for a split second) before resuming. Some times it does this, but then cranks strongly the next time I push the start button. It has me thinking that a bad start button is a second problem with the system.

[RobertTravis]

It may have just required more starter oomph because one cylinder was about to fire under compression. I'd put a new battery in it. Under 11v or so and it won't light the candles.

[TripleKing]

It may have just required more starter oomph because one cylinder was about to fire under compression. I'd put a new battery in it. Under 11v or so and it won't light the candles.

I agree, although it started and cranked ok, with the load dropping to between 10 and 11 volts. Another think I discovered that at least one of my maintenance chargers will not push batter past 13.1 volts, before shutting off as "fully charged," but my big charger will get it above 14 volts before indicating fully charged. Also, from a state to from were it is in the mid-12 volt area to the low 13s, the maintenance charger I used today took about 30 minutes.

I agree that the battery needs replacing, but I believe there is a separate high draw situation happening. Power to the coils is fine. Power to or the draw from the starter may be the secondary problem.