ETZ251 charging system

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ETZ251 charging system

Postby Blurredman » Fri Mar 17, 2017 1:37 pm

Hi guys.


Just quick question. After I've had issues with my coil and electronic ignition, I put on a cheapo volt display. I have this wired from ignition. Now this is the only bike I have installed one on ('90 ETZ251) and I'm a little concerned about the readings.


With the lights on and indicators going, it normally hovers around 10.5v. With the lights off the bike is around the 13v mark at idle. And whilst riding I get around 13.8 /13.9 displayed. Is this really enough to support the battery?


I use the bike for commuting, and every time I come to use the bike after work/to get to work, the display initially says 12.3. I need to double check the 'true' value with a volt-metre incase the volt display under-reads, but when Idling after a long time (a few minutes) with the lights on the discharge light does come on very faintly. Recently, I've noticed the battery voltage after sustained use with the lights on is less than it normally is when at a run. I don't think the system is sufficiently charging.


- The regulator is a solid state one and does seem to do it's job.. It doesn't allow a voltage above 14.5v when revving the bike (without load).
- The electronic ignition is DC based and apparently uses only 10mA.
- The battery is a new 9ah.

I never really delved into the charging system of the Mz's before because my other MZ always seemed to work and never had issue with the charge. That bike still has mechanical regulation and the discharge light has never come on (in use). I did check it with a voltmetre (first time in years) the other week to find that it also has around the same values as the above example. My brother's bike is the same too, and I also read a message on a thread here where someone stated their MZ was getting just above 10v at idle and was happy because that now said their system was working..

What sort of charge should I get??? And even though all components seem to be doing their job more or less, how can I increase the rate of charge to a more happy 14.5 (or so) volts?!?!?!
1979 Suzuki TS185ER - 8,500 miles - Mud :)
1981 Honda CX500B - 77,000 miles - Rain :)
1987 MZ ETZ300 - 29,000 miles - Sun :)
1990 MZ ETZ251 - 31,000 miles - Commute :)

ftp://www.blurredmanswebsite.crabdance.com/Vehicle_Documents/MZ_Documents/
Blurredman
 
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Re: ETZ251 charging system

Postby DAVID THOMPSON » Fri Mar 17, 2017 3:50 pm

over 14.00 is hard on bulbs and stuff
if running down the motorway and its showing 13,0 to 14. you should be doing OK

turn signals are power hogs turn them on when you come to the head of a stopped line of traffic and are next

or as a warning about 75 to 100 feet before you turn when moving
the object is to be seen but not run the battery down by over use

and a 12volt 9ah battery is a joke find a place to install a bigger one
Dave 2002 MZ RT125 +1995 Saxon Tour (rotax500cc)
1997 MZ Skorpion Traveller added 6/13/09
Located in WV USA
"I like the road less traveled if it's PAVED!"
E mail wd8cyv at yahoo dot com
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DAVID THOMPSON
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Re: ETZ251 charging system

Postby Blurredman » Mon Mar 20, 2017 5:58 pm

Thanks Dave.


The little LED Voltage display actually reads a little low compared to what a proper multimetre gives. 12.45 on the metre = 12.3 on the Mini display. 12.4v on the metre reads 12.1 on the display. So I'm a bit happier now that the batter although is technically a little low seems to be charging sufficiently. So.. when in use the display is 13.5, but what is more likely 13.7v.

I will at some point put additional earth points on the engine and frame just to reduce resistance in the circuitry. Not sure if it will do anything, but I have a huge box of wires to which I can experiment with this pursuit.

I may or may not put LED bulbs in the system. I'm undecided yet on that.


As for the 9ah battery, that is standard for a etz250, however my other etz250 worked perfectly fine for years on a 5.5ah battery with no indications of voltage loss (at least by indication of the dis-charge light).


:-D :-D :-D
1979 Suzuki TS185ER - 8,500 miles - Mud :)
1981 Honda CX500B - 77,000 miles - Rain :)
1987 MZ ETZ300 - 29,000 miles - Sun :)
1990 MZ ETZ251 - 31,000 miles - Commute :)

ftp://www.blurredmanswebsite.crabdance.com/Vehicle_Documents/MZ_Documents/
Blurredman
 
Posts: 181
Joined: Sat Feb 09, 2013 3:59 pm

Re: ETZ251 charging system

Postby DAVID THOMPSON » Mon Mar 20, 2017 6:50 pm

all my bikes are started by the electric rubber band and it looks at a a 9ah battery and has a laughter attack
Dave 2002 MZ RT125 +1995 Saxon Tour (rotax500cc)
1997 MZ Skorpion Traveller added 6/13/09
Located in WV USA
"I like the road less traveled if it's PAVED!"
E mail wd8cyv at yahoo dot com
User avatar
DAVID THOMPSON
Moderator
 
Posts: 4346
Joined: Sun Nov 23, 2003 11:01 am
Location: Parkersburg, West Virginia USA .questions answered MZ 95 up, BMW 1953 to 1979 and ham radio WD8CYV


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