2.5 260 charging questions

[kjdoo4]

I have 93 2.5 EFI 260 I just picked up a couple months ago. What are real numbers for what the charging system can produce? I know its a 16 amp system with regulator on it. I've searched the forum and see that people say it can make 14 volts and others say it wont make any voltage above 12.6 No matter what rpm I do, I cant make enough to charge battery. I'm always around 12.1 with the fuel pump and ecu drawing there amps. Do I have a proplem or is this just the deal with such a low amp system. I am running 2 brand new agm batterys in the system. Any insight would be helpful. Thanks again

[j_martin]

The stator generates up to 14 amps at 15 V per 1000 rpm. That would be 75V at 5000 rpm. The current is safely limited by the design of the stator.

The voltage out of a rectifier is limited by the battery, with the excess hydrolyzing the electrolyte in the battery. A good battery will limit it to around 14.4 V fully charged.

A regulator, if that's your setup, should fully charge to about 13.8V, then ramp downto 14.4V at 0 amps.

In other words, your charging system is broken.

[superboattwin250]

260 don't charge because they make 16amps at 5k. But the draw of the fuel pump, ecu, injectors, trim and other electrics draws more than the stator makes. So you end up with a dead battery by the end of the day. Charge it up after every time you run it. It is a race motor

[stvgar]

Pretty typical complaint for a 260. Most happy 260 owners charge before going out to be safe. The same charging system keeps up fine on a 245 carb motor running only a red Holley low pressure pump.

[Capt.Insane-o]

260 and charging the battery is like obamas health care.

[luv2gofast]

I agree with J_Martin. I don't think you charging system is working at only 12.1v. You could easily remove the load of the fuel pump, probably the highest draw component, by disconnecting it and running it off of another battery - jump box. I think you will probably find a bad rectifier. I also don't disagree that the 14A charging system is barely enough to support the motor so good luck trying to run a stereo and amp...

[Go Time]

Why do you think the Promax is so popular...
;)

[kjdoo4]

Thanks for the input. Going to do some checking this weekend to make sure it's a least working how it should. I will say even though it might not charge well, I still love the power of the engine so far.

[Go Time]

My 260 puts out 12.1V at idle then increases as RPM increases. I get 12.5 volts at 1800 RPM. You should be OK as long as you dont have a bunch of addition electronics like depth finder & big stereo.

[johnmiffco]

the agm batteries u are using have a very deep cycle if u have the minimum of a 24 series
27 series are better for deep cycle,,,,
I have 3 of these motors running on 2 27 series exide agm batteries
with an onboard charger I charge up before I go out
run minimum 100 gallons of fuel and 20+ 3 motor starts
also run a 3rd 31 series for big stereo running on 2 jl amps
do offshore fun runs and poker runs
and never had a batteriy issue of any batteries going dead
as stated were built as a race motor so minimum charging for minimum power loss
from charging resistance to flywheel

[Laser88]

My buds and me are all in the same situation as yours. We start by removing the wires to the voltage regulator, and even then we're happy to charge the batteries once or twice a month. Just think of it a maintenance... BTW, I keep one of those lithion ion kits on board, learned that lesson the hard way...