Should I Disconnect the Onboard B&S Regulator and Use a 10SI Alternator?

[geochurch]

Hi All, hope this is posted in the correct area, we have a Briggs &Stratton motor with a built in charging system, because of additional load a Delco Remy 10SI alternator was fitted to end of the motor to supply additional charging capacity to the battery, any thoughts on this configuration, I am thinking of disconnecting the onboard B&S regulator/ rectifier and using the 10SI.
Geo
Geo

 

[Baluncore]

Welcome to PF.
Does the B&S provide mechanical traction ?
What uses the extra electrical power ?

I expect the B&S will have an unregulated AC winding on the magneto, with a bridge rectifier, followed by a switching battery charging regulator to maintain the battery charge for starting. That could be disconnected without a problem if there was an alternative charging current. You would then rely on the vehicle alternator to maintain the start battery.

The question I have now is, how do the two regulators work together ? They were designed for different magnitudes of battery capacity, so charge rate may be a limiting factor.

Why not run two separate systems, with two different capacity batteries?
The alternative is to run only the higher capacity system.

PS. We need a picture of the body shell, locomotive make and model.

 

[Averagesupernova]

I've seen that EXACT engine running an extra alternator. It was on a portable sawmill that was a factory option on the mill due to an electric debarking head that ran ahead of the band. Not something I saw at an auction or etc. I was involved with this particular company.

 

[geochurch]

As it stands now, I am fully charging the battery with an external charger, when tested this AM output from alternator with onboard charging system disconnected the output from the alternator was 10.8 VDC, with alternator removed and onboard reconnected about 12.4 VDC, additional load that as supposed to need more power for the sound system.
Geo

 

[tech99]

Why do you need two generators, is it to get more charging current? Remember the engine supplies mechanical power to both.

 

[Baluncore]

Why do you need two generators, is it to get more charging current?

The low current AC winding on the magneto provides only sufficient energy to maintain the engine start battery. If you need more current it must come from another source.

 

[Baluncore]

... I am fully charging the battery with an external charger, when tested this AM output from alternator with onboard charging system disconnected the output from the alternator was 10.8 VDC, with alternator removed and onboard reconnected about 12.4 VDC, additional load that as supposed to need more power for the sound system.

That seems backwards to me. I would expect the lower voltage from the magneto winding under the extra load. Assuming a 12 V battery, the 10SI should charge to about 14.0 V.

The "Delco Remy 10SI alternator" is rated to 63 amp, and has an internal voltage regulator. Has it been connected correctly?
Were those measurements made with the battery connected and being charged?

There are now battery charging voltage regulators on magneto alternators that produce no voltage output, unless they are first connected to a 12 V battery.

 

[Averagesupernova]

Sounds like the battery is seriously discharged to begin with. Also, is the outboard alternator defective or hooked up wrong?

 

[geochurch]

The low current AC winding on the magneto provides only sufficient energy to maintain the engine start battery. If you need more current it must come from another source.

After further investigation this AM, I determined that the RPM’ s were set to low to produce the required 14+- volts to keep the battery charging, raised the RPM’s and everyone seems happy, no need for the add on alternator, load from sound system and lights about 6Amps .
Geo