Topic: Charging the CB400f up to 16.5, nice!

[jacquesleclochard]

So what gives? The guy who rode it to the shop was losing power, cooking batteries, and the old regulator jumped to about 16 as well. Replaced both the reg and the rectifier with a combi unit from Electrosport. Checked the wiring for cracks or bad terminals, installed a new dynamo, stator wires check out okay. I'm at a loss! Is this bike supposed to charge that high? I don't think so?

[flybox1]

14.5 max at anything over 5000rpm.
is it adjustable?

[TwoTired]

The regulator controls based on what it knows at it's terminals.  When the battery is at 16V what is the voltage at it's sense terminals?

If the sense terminals are at 12V, it thinks the battery need more charging.

[jacquesleclochard]

I'm sorry TT, lost in translation there. What's a terminal?

[TwoTired]

I'm sorry TT, lost in translation there. What's a terminal?

A connection point.

The regulator lives in a box.  It connects to the ("its") outside world via wires or terminals.  The original Vreg had three connections;  Black, White, Green.  Black and green are the sense/input terminals.  These have to have the same voltage potential as the battery in order to know what the battery is doing.

So, you check for Voltage loss (Vloss) by measuring both devices simultaneously with two identical voltmeters.

Or... you place one voltage meter probe tip on the Battery POS post and the other on the Vreg input/Sense connection terminal. (black)  The meter reports the difference between the two points.
You should also measure the Battery NEG to Vreg Green. Note the reading and add it to the prior test to give the total error voltage being reported to the Vreg from the battery.
The above tests are done with the keyswitch and all lighting turned on.

[becken]

I'm sorry TT, lost in translation there. What's a terminal?

A connection point.

The regulator lives in a box.  It connects to the ("its") outside world via wires or terminals.  The original Vreg had three connections;  Black, White, Green.  Black and green are the sense/input terminals.  These have to have the same voltage potential as the battery in order to know what the battery is doing.

So, you check for Voltage loss (Vloss) by measuring both devices simultaneously with two identical voltmeters.

Or... you place one voltage meter probe tip on the Battery POS post and the other on the Vreg input/Sense connection terminal. (black)  The meter reports the difference between the two points.
You should also measure the Battery NEG to Vreg Green. Note the reading and add it to the prior test to give the total error voltage being reported to the Vreg from the battery.
The above tests are done with the keyswitch and all lighting turned on.

Is this test done with the engine running?

[flybox1]

I'm sorry TT, lost in translation there. What's a terminal?

A connection point.

The regulator lives in a box.  It connects to the ("its") outside world via wires or terminals.  The original Vreg had three connections;  Black, White, Green.  Black and green are the sense/input terminals.  These have to have the same voltage potential as the battery in order to know what the battery is doing.

So, you check for Voltage loss (Vloss) by measuring both devices simultaneously with two identical voltmeters.

Or... you place one voltage meter probe tip on the Battery POS post and the other on the Vreg input/Sense connection terminal. (black)  The meter reports the difference between the two points.
You should also measure the Battery NEG to Vreg Green. Note the reading and add it to the prior test to give the total error voltage being reported to the Vreg from the battery.
The above tests are done with the keyswitch and all lighting turned on.

Is this test done with the engine running?

No

TT -  simple test to perform.  I will be doing this today.  (my background is non-electrical, but im trying)
I'm assuming, ideally, total error should be as close to 0.00v as possible.  Is there an acceptable error value for our 30+year old bikes before we start in on troubleshooting?

[TwoTired]

I'm sorry TT, lost in translation there. What's a terminal?

A connection point.

The regulator lives in a box.  It connects to the ("its") outside world via wires or terminals.  The original Vreg had three connections;  Black, White, Green.  Black and green are the sense/input terminals.  These have to have the same voltage potential as the battery in order to know what the battery is doing.

So, you check for Voltage loss (Vloss) by measuring both devices simultaneously with two identical voltmeters.

Or... you place one voltage meter probe tip on the Battery POS post and the other on the Vreg input/Sense connection terminal. (black)  The meter reports the difference between the two points.
You should also measure the Battery NEG to Vreg Green. Note the reading and add it to the prior test to give the total error voltage being reported to the Vreg from the battery.
The above tests are done with the keyswitch and all lighting turned on.

Is this test done with the engine running?

Kinda optional.  With the Alternator charging, the pure resistive loads on the bike will draw more current at a higher voltage.  Drawing more current through resistive contacts and connections will cause more voltage loss through them.  Since most devices are powered through the black wire distribution lines.  Larger loads and a larger voltage supply will make the inline losses show bigger numbers, and point to themselves as a problem to correct.

[jacquesleclochard]

Thanks for the replies. I cleaned all the connections, and fired it up with the battery in place. Added another ground, but was pretty sure the original ground was sufficient.

Charging rates changed. Steadily climbs up to 14.6 and lingers around those values. No jumping in the voltage or anything, just a steady slope. Not sure if this is good or not. Taking it for a test; I still don't feel really confident with it.

[TwoTired]

TT -  simple test to perform.  I will be doing this today.  (my background is non-electrical, but im trying)
I'm assuming, ideally, total error should be as close to 0.00v as possible.  Is there an acceptable error value for our 30+year old bikes before we start in on troubleshooting?

Yes, zero V loss is ideal.  My metric for needed action trips at a V loss of more than .5 V.  If the glass fuses aren't overheating and burning your thumb, the major problem usually shows up in the key switch contacts.  However, if every connector (a hundred-ish) on the bike increases resistance, by 0.1 Ω, it all adds up to wasted power thrown away as heat, and in effect, takes power away from the alternator better used by end devices and battery charging.

Glad you are taking the time and effort to learn.

[TwoTired]

Thanks for the replies. I cleaned all the connections, and fired it up with the battery in place. Added another ground, but was pretty sure the original ground was sufficient.

Charging rates changed. Steadily climbs up to 14.6 and lingers around those values. No jumping in the voltage or anything, just a steady slope. Not sure if this is good or not. Taking it for a test; I still don't feel really confident with it.

14.6 V is okay, if you know beforehand that the battery is at full charge prior to the measurement.  To charge a battery you must supply more voltage than it has all by itself.  Strictly speaking, 14.6V could be a voltage of a slightly depleted battery accepting a higher charge voltage, to be eventually limited at 16V (which would be bad) when the battery can accept no more charge energy.  Or, the Vreg may be limiting the peak battery voltage at 14.6V, which is perfectly acceptable for blissful riding. 

[becken]

TT, it's always a pleasure reading your replies. Thank you for taking the time.