Battery Life

Little Loris · Post by **Little Loris** » Jan 5th, '07, 16:04

I tried starting my bike last night and I think the battery has died on me. The engine sounded like it was turning though, so I'm thinking the worst (regulator/rectifier).

Tuesday night had a similar problem. After I'd ridden from Exeter to Taunton it wouldn't start or turn over. Lights, ignition and fan worked ok but after a charge of 2 hours or so I could get back down to Exeter.

How can I tell if the battery is old and just needs a charge or if it's life is coming to a dreary end? Any advice would be really appreciated.

(I intend to swap the batteries over with another I have from the ZXR400 and see if it is a battery problem and that should eliminate me panicking about a reg/rec problem).

Post by **TLS-Moose** » Jan 5th, '07, 17:40

Where abouts in Exeter do you work ? If you are able to get to marsh Barton, try the Exeter Battery Centre in Cofton Road (left by the Citroen garage, then left again, and they're about 1/2 way along on the left). They should be able to test it for you.

If you are the other side of town, try Derek at CMS

As a simple check to see if it's charging, with the battery in a low state of charge turn the lights on and rev the bike up from tickover to 4-5k rpm a couple of times.....as the revs rise the lights should brighten then drop slightly as it returns to tickover. If they don't brighten, then it ain't charging

If you have access to a multi-meter, it should be putting out about 14v (measured accross the battery terminals) or so at mid-revs

DynaMight · Post by **DynaMight** » Jan 5th, '07, 18:37

Could be battery, Kellys used to drop it's voltage quite quickly and not start. Fitted a 'new' battery and now it's perfect. Bring it around if you want, I've got a Multimeter and Optimate charger.

Mark-Blade · Post by **Mark-Blade** » Jan 5th, '07, 19:20

Bondy put me on to a realy cheap and easy to use tester, available from most car spares shops. Simply connect across the battery terminals, and with the engine running, shows charge rate, and battery condition with engine off. Cost about a tenner I believe.

Little Loris · Post by **Little Loris** » Jan 5th, '07, 20:19

Thanks for the advice. Santa got me a multimeter for Chrimbo so I can give that a go - I didn't know you could use it directly onto batteries!

I'm back in Taunton this weekend so will give it a go and let you know.

Thanks again!

Post by **Dave** » Jan 5th, '07, 23:05

First thing to do is clean up the earth point and check over connections to the battery, regulator and magneto. This is often overlooked and can cause loads of problems, if any connections are rusty clean then up and check again.

The next thing to do it check your battery with everything off, this should read above 12volts, if it's lower then it is certainly a duff battery.

Check the voltage again with the engine running, if it is running at 13.5v and above then the regulator seems fine and the drain could be from an earth. If it is losing voltage then the next thing to do is check the regulator. Regulators can vary, but they all have a postitive and a negative, the other wires are the phases. Using the multimeter check for continuity between the wires. If their is any continuity between the phases then the regulator has burnt out.

While you are at it I would start the bike with the regulator off, and check the phases that come from the magneto to the regulator. Each of these should read between 70-140volts, if it is any less or if it fluxuates then you also have a charging problem that could have caused the magneto to burn out.

If these wires do not read between 70-140volts then check the same wires again, but this time check the connector coming straight from the magneto, if this is fine then it is the wires at fault, if not then you need to check the phases on the magneto for continuity. If there is continuity then you have a faulty magneto. If it is not look for cracks and chips around the stator flywheel, or that the pickup has not become damaged.

If you see any problems sort them ASAP becuase Magnetos and Regulators are not cheap (Trust me I know).

If you are still stuck after reading all this or do not confident carrying out these tests, please either take it a local garage or PM me if you can make it to Exeter.

And remember, there is alot of voltage coming out from the magneto, whatever you do, DO NOT STICK YOUR TONGUE ON IT !

Little Loris · Post by **Little Loris** » Jan 9th, '07, 08:10

The battery seems to be losing its charge somewhere because it started first time on Saturday without having to charge it up

Without starting the bike the voltage is about 11v and when started, its about 13v. Revved up to 4k revs its about 14v. With lights on, about 12v and with fan on about 11v.

After starting the bike Saturday it did die on me after about 30 seconds when the revs dropped and it cut out. After that it started fine.

All this talk of megnetos and regulators makes me nervous

Post by **TLS-Moose** » Jan 9th, '07, 09:09

Sounds to me like a dead battery. If it's low volts at start, but rises when revved.

By the fact that you say when revved it climbs to 13 - 14v, that implies the charging circuit is working, but the battery is unable to hold it's charge. Don't forget that batteries work poorer in cold weather

Little Loris · Post by **Little Loris** » Jan 14th, '07, 14:28

Well, I gave the Optimate a go and it seems the battery is fine, so I'm guessing I have a reg/rec fault