high-amperage generator output; how much is too much?

Barry in St.Paul

Barry in St.Paul

Senior Member
hi,
my stock generator (rebuilt armature and coils) has an EVR which seems to work a little differently with my Optima battery. It is typically 'all or nothing' charging, no or low charge until the EVR senses the voltage is below the cutoff point, then pumps out 20 amps (per repro dash gauge, I have no means of measuring it more accurately) for a few minutes, then drops back down to just a few amps or nothing again. Does its job keeping the battery charged, no problem there. But I am wondering if pushing out 20 amps for a few minutes at a time is a risk to my armature? I know CONTINUOUS high-amperage will burn out an armature, but is that simply from the heat building up internally? And if so, maybe not a problem with my situation since it only charges at 20amps for a few minutes at a time before dropping back down to an idling or low-charge mode? I like my Optima battery, and I like the EVR. :-) I suppose I could add one of those "generator cooler" bands if necessary....
Thoughts?
thanks!
 
You didn't say which evr you are useing. I use the Fun Projects regulator that takes the place of the cut out. On the 6 volt version Fun regulator you are suppose to adjust the third brush for a 15 amp maximum charge and the 12 volt version is to be set for an 8 amp max charge. I always use a cut out for setting the charge rate before mounting the regulator. The ones that I use work like modern day voltage regulators. when the regulator senses that the battery needs more charge it will charge up to the maximum setting of the third brush untill the demand is met, then the ammeter needle will drop back to just a few amps or zero. A constant charge of 20 amps would be bad for the armature and it would boil the battery pretty quick. I think that any of the model A generators would last longer with a generator cooler band. I use them on a couple of my cars and they are easily removeable.
 
I think 20 amps is an awful lot for that poor little generator.. I really don't have a problem with the way Henry thought it should be,, but,, I do like the EVR that Tom W makes.. It works well[ no third brush] and seems pretty bullet-proof in that there are no worries about a runway due to an open..
 
A twenty amp charge with a regulator is not going to hurt the generator because it will only charge 20 amps for a VERY short time. I would be more concerned about harm to the regulator if it is above the recommended maximum charge. It would be interesting to know which EVR that Barry is useing, 20 amps maximum charge may not be Too much for some regulators. I only have experience with one.
 
Thanks Barry, Its good to know that Toms EVR will allow a higher maximum charge. If only he would ok them for twelve volt use, his market may expand. It'll never happen, Tom is pretty much set against 12 volts.
 
I would not put much faith in the amp meter if it is a repro. Heck, even if it is an original I would only use it for a gross idea.

Get someone to help you that knows how to use a volt-ohm meter. Do not try to rectify any problems until you have verified you have a problem.
 
Give Tom a call, he may be the best place to get an answer. I know he was out of town this weekend, saw him at the Grand Rapids swap meet, not sure when he was returning.
 
With the third brush, I never let it charge more than 12 amps and even with one of Toms EVRs I can't recall ever seeing more than 12 amps from it[ it certainly never hit 15]..
 
Ive run my amps when i gas it between 15&18 it dosent seem to mind someone said if it aint broke dont fix it . latecomer.
 
Ive been having that comon problem of overheating 29 model a can t seem to narrow it down. radiator is old but seems to have good flo and flushed clean. should i have record or just look further. latecomer
 
Kevin in NJ said:
I would not put much faith in the amp meter if it is a repro. Heck, even if it is an original I would only use it for a gross idea.

Get someone to help you that knows how to use a volt-ohm meter. Do not try to rectify any problems until you have verified you have a problem.
Click to expand...

Kevin, I have an industrial Fluke Multimeter, but it is only rated for 5amps and afraid I'd burn her out on this task. I only use it for voltage and continuity testing.....
 
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