Hi All, Im back again with an electrical problem now! I think my 3aj may not be charging, Now im no autolectrician,but i have bought a multimeter and have done the following checks: With the bike idling i have 13.2 volts at the battery terminals, with the battery disconnected and the bike still idling and with the lights off i have 01.0 volts at the terminals, with lights on its 11.0 volts. does this make any sense? what else should i be poking my multimeter at? and what should it read when i do? The reason i think its not charging is, when i rev it the lights actually dim down rather than brighten up! also when i take it for a spin (20miles say) and it has been stopped long enough to cool down, it will not start ie battery is flat. I always keep the battery on charge with an optimate trickle charger when the bikes not in use. I know virtually nothing about electrics so go easy on me!!! Thanks in advance for any help. T

__________________
big T

Hi mate, I think you have overcharged and killed your battery...

The battery running flat is usually due to a faulty regulator/rectifier (under the rear fender) but you saying that you always keep it charging on that optimate trickle charger might be the cause of the flat battery...

if you can test a friends regulator/rectifier just charge the battery and ride it for a while...

Vando

OK do this:

charge the battery with the charger.
check volts, they should be around 12,8 or at least 12,5
if not battery f****ed replace

if ok

connect battery to the bike.
turn the lights on and check volts on battery terminals.
if goes quickly down, battery f****ed replace

then

with the battery ok (or the new one)
turn engine on, check volts, they should be something over 13, no more than 14,5. Bring engine to 2000\3000 rpm and see if goes over 14,5 volts,
if you have more than this value regulator is f****d replace it.

Remember:
using your bike with no battery, or with discharged battery for long time can do damages.
a regulator that gives more than 14,5 will cook spaghetti inside your battery



Hi All, Im back again with an electrical problem now! I think my 3aj may not be charging, Now im no autolectrician,but i have bought a multimeter and have done the following checks: With the bike idling i have 13.2 volts at the battery terminals, with the battery disconnected and the bike still idling and with the lights off i have 01.0 volts at the terminals, with lights on its 11.0 volts. does this make any sense? what else should i be poking my multimeter at? and what should it read when i do? The reason i think its not charging is, when i rev it the lights actually dim down rather than brighten up! also when i take it for a spin (20miles say) and it has been stopped long enough to cool down, it will not start ie battery is flat. I always keep the battery on charge with an optimate trickle charger when the bikes not in use. I know virtually nothing about electrics so go easy on me!!! Thanks in advance for any help. T

Thanks, i will try these things and report back. I thought an optimate trickle charger was meant to keep your battery in good condition?? if not, whats the point? thanks again: T

__________________
big T

The trickle charger makes no damage to your battery, if died in a few months surely the problem comes from regulator

You wont be the first to have made that assumption incorrectly. It is true that a bike trickle charger wont damage the battery while charging (i.e. cook it) but once the battery has charged; if the charger does not automatically cease, even a trickle charge, will degrade the battery performance over time. A number of people have come to grief over winter storage and trickle chargers.

I use lead acid batteries to cycle charge Li-ion, NiCd and NiMH batteries for RC. The care of the lead acid batteries has actually proved more difficult over their lifespan.

The Optimate is designed to be left on the battery for long periods. After giving a full charge, it goes into a test mode. It stops charging for a while, and then checks to see if the voltage from, the battery has dropped. If volts have fallen below a certain level (i.e. the battery isn't holding its charge properly) it will report a faulty battery. Otherwise it just delivers a float charge and keeps checking itself.

I use my bikes too much to know if it works over very long periods, but I have friends who park the bike in October, plug in the Optimate, and dig it all out again in April. None have ever cooked a battery that way to my knowledge.

fair enough, I am not familiar with the Optimate itself.

Never to forget that rechargeable batteries (at least most of them) have a cell memory just like cellphone batteries for example.

Vando

I think that only applies to the older NiCads, not the lead-acid or gel type used in bikes. I've never noticed any memory effect in a car or bike battery. I'm sure someone will be along shortly to say we are both talking rubbish