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Discussion Starter #1
Is there any way to increase the alternator output voltage?
Like a diode mod or via modifying the PCM?
 

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Is there any way to increase the alternator output voltage?
Like a diode mod or via modifying the PCM?
Last time I was looking into more power for the 1000 Watt amp, I considered putting this "ultracapacitor" next to the amp:


Which you can get at a discount because there was a NHTSA recall on the product early on I believe. I may look at alternatives if I go that route down the road. What's your application?
 

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Discussion Starter #4 (Edited)
The idle voltage output from the alt is too low (~13V) for my lifepo4 battery. I want to raise it ~200mV.

For LiFePO4:
281580


I'd also be interested in seeing what the PCM's battery charging algorithm looks like, and potentially modify it to better suit lithium vs lead
 

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Discussion Starter #6
lol guys i appreciate the concern but i don't need a nanny, i need options.
 

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lol guys i appreciate the concern but i don't need a nanny, i need options.
I think I see where you're going. Boost the alternator voltage by 200mv and you about double your capacity. Have you considered a Big 3 Upgrade yet?
 

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Discussion Starter #8
so i actually did some datalogging of the ECU voltage:
281609

This is from a cold start. The voltage is about 13.15V with the ignition "ON". but a fully charge LFP battery should be 13.5-13.6V. I'm unsure if this is since i'm reading from the ECU or if battery output voltage is limited by the BMS.

irregardless, the ecu never sees 14V
 

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so i actually did some datalogging of the ECU voltage:
View attachment 281609
This is from a cold start. The voltage is about 13.15V with the ignition "ON". but a fully charge LFP battery should be 13.5-13.6V. I'm unsure if this is since i'm reading from the ECU or if battery output voltage is limited by the BMS.

irregardless, the ecu never sees 14V
What happens if you turn on the parking lights?

I have an Isuzu truck that does this. Isuzu programmed the alternator controls to essentially never charge the battery fully in order to save fuel. Some Isuzu owners install a resistor in the alternator circuit to ensure it always senses a load and charges at full voltage - that's important if you run a second auxiliary battery via a DC/DC charger.
 
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