Battery Diagnostics

That is interesting. I don't recall this charging issue coming up on 1980 650's with Dyna S ignitions. I guess the original poster could simply try to use a later reg/rec with the brown sense line. (That is, if it turns out his charging system cannot produce 14.2v or so when above 2000 RPM continuously.)

bountyhunter wrote:

650 in Vegas wrote: It sounds like it is unanimous that a new battery is needed, which is what I expected. With a new and fully charged battery, what amount of drop should I expect with the ignition on and the switch to "run"? I am trying to get a feel for what some of the acceptable tolerances are so I will know if I am killing the new battery.

Also are then any battery types that are less susceptible to problems from these older charging systems? AGM vs gel vs lead acid...

I think AGM is the best value for the buck.

+1
Scorpion AGM from Batterystuff.com has worked great for me on my 550's. I think they should have an option for the 650.

I am glad that you brought that up as I almost forgot to mention it. I was only using a freebie harbor freight multi-meter, but when I checked the voltage across the terminals with the rpms to 4000 like the Clymer manual suggests, I was getting readings everywhere from 14 to 20 volts and it was bouncing around so fast that I don't really have any confidence in any reading. Is this perfectly normal, a sign of a blown reg/rec, or just a crappy meter?

If the voltage readings across the battery terminals are higher than 15v the voltage regulator is not working properly. It should limit the voltage to no greater than 15v. Ed

650 in Vegas wrote: I am glad that you brought that up as I almost forgot to mention it. I was only using a freebie harbor freight multi-meter, but when I checked the voltage across the terminals with the rpms to 4000 like the Clymer manual suggests, I was getting readings everywhere from 14 to 20 volts and it was bouncing around so fast that I don't really have any confidence in any reading. Is this perfectly normal, a sign of a blown reg/rec, or just a crappy meter?

I had this problem and M folks told me I had the meter too close to the charging system and he was right ...... try moving the meter to the rear of the bike as far as you can get away from the motor.

KZB2 650 wrote:

650 in Vegas wrote: I am glad that you brought that up as I almost forgot to mention it. I was only using a freebie harbor freight multi-meter, but when I checked the voltage across the terminals with the rpms to 4000 like the Clymer manual suggests, I was getting readings everywhere from 14 to 20 volts and it was bouncing around so fast that I don't really have any confidence in any reading. Is this perfectly normal, a sign of a blown reg/rec, or just a crappy meter?

I had this problem and M folks told me I had the meter too close to the charging system and he was right ...... try moving the meter to the rear of the bike as far as you can get away from the motor.

or get an old fashioned analog meter...... :laugh:

loudhvx wrote: That is interesting. I don't recall this charging issue coming up on 1980 650's with Dyna S ignitions. I guess the original poster could simply try to use a later reg/rec with the brown sense line.

1980 reg/rec and new AGM battery ordered. I'll keep you posted as to the results.

No eBay APP ID and/or Cert ID defined in Kunena configurationbountyhunter wrote: "or get an old fashioned analog meter....."

+1 Either that or a decent digital meter. Mine is like the one below and I've never had any problems readings jumping or being inaccurate. Ed

And if your really in a spending mood you could buy 7 or 8 and take the average reading...... but it might be a better idea just to use the extra money to fix the problem.