Alternator voltage (1 Viewer)

[mbennett22]

I have been going through the forum and noticing a lot of people saying that their voltage from the alternator is 13.4 some are 13.6. I wanted to start this poll in order to see if I really need to look into getting a new alternator or let it ride. We are going on vacation on August 9th and will be away from civilization. Not sure if it matters but I have a 2009. Thanks!!!!

 

[TeCKis300]

13.0 - 14.4V

It varies and is not directly comparable as it's a temperature sensing alternator. Ambient temps play a part. A hot engine and heat soaked engine bay play a part. I've seen really hot weather and slow off-road crawling bring the alternator output down to ~12.9V. Because that's what the lead acid battery wants, and it's important to avoid electrolytes boiling over.

What's clear is that it probably shouldn't be lower than ~12.8V (measured at the posts) with a running engine. Either more load than the alternator can support or there's an issue.

 

[mbennett22]

13.0 - 14.4V

It varies and is not directly comparable as it's a temperature sensing alternator. Ambient temps play a part. A hot engine and heat soaked engine bay play a part. I've seen really hot weather and slow off-road crawling bring the alternator output down to ~12.9V. Because that's what the lead acid battery wants, and it's important to avoid electrolytes boiling over.

What's clear is that it probably shouldn't be lower than ~12.8V (measured at the posts) with a running engine. Either more load than the alternator can support or there's an issue.

Thanks for the comment, I forgot to mention that I do have a dual battery system with a redraw bcdc1225. Is the dual battery putting more strain on the alternator. I have also seen some post about the voltage booster blade fuses some are running on their rigs. I am thinking about going that route to bump up my voltage just a bit.

 

[TeCKis300]

Thanks for the comment, I forgot to mention that I do have a dual battery system with a redraw bcdc1225. Is the dual battery putting more strain on the alternator. I have also seen some post about the voltage booster blade fuses some are running on their rigs. I am thinking about going that route to bump up my voltage just a bit.

The booster diode doesn't really create more output potential from alternator. It just tricks the regulator to run a more aggressive voltage curve. That'll depend more on what type of starter battery you have. Though raising the voltage/charge profile has more potential to shorten the starter battery life as again, the stock output profile is tailored to walk the right balance for charging and long battery life for a standard lead acid.

If you're really looking for more output potential, an alternator upgrade is what's necessary. An overdrive pulley can create a bit more output too as I did here.

More Power! Alternator on Overdrive

Following in the footsteps of @FrazzledHunter and his full 390A alternator upgrade: Alternator upgrade - done! - https://forum.ih8mud.com/threads/alternator-upgrade-done.1329033/ What A smaller alternator overdrive pulley and matching belt to spin the OEM 180A alternator ~16% faster. Not...

forum.ih8mud.com

 

[FrazzledHunter]

13.0 - 14.4V

It varies and is not directly comparable as it's a temperature sensing alternator. Ambient temps play a part. A hot engine and heat soaked engine bay play a part. I've seen really hot weather and slow off-road crawling bring the alternator output down to ~12.9V. Because that's what the lead acid battery wants, and it's important to avoid electrolytes boiling over.

What's clear is that it probably shouldn't be lower than ~12.8V (measured at the posts) with a running engine. Either more load than the alternator can support or there's an issue.

When I first looked at the thread I wondered how I could possibly vote as I have probably seen the alternator at all those voltages!
I know it goes well over 14V but I have never been able to record a max. voltage.

 

[2021 LC200]

Not checked yet with a multi meter at the battery, however dash gauge with factory lead acid battery (Panasonic, 105D31L - MF, 20Hr 80Ah CCA650A) showing 13.9 +/- 0.1 volt, pretty much after the initial few minutes. My vehicle was build Oct 2020 and I do check about annually the fluid level and add small amounts of distilled water to keep things in shape.

 

[daneo]

Thanks for the comment, I forgot to mention that I do have a dual battery system with a redraw bcdc1225. Is the dual battery putting more strain on the alternator. I have also seen some post about the voltage booster blade fuses some are running on their rigs. I am thinking about going that route to bump up my voltage just a bit.

The dual battery is putting more strain on your alternator, yes.

Are you seeing any symptoms of stress or failure? It seems like you’re trying to put band aids on a wound that isn’t there. Relax and let it ride. Enjoy your trip.

 

[TeCKis300]

When I first looked at the thread I wondered how I could possibly vote as I have probably seen the alternator at all those voltages!
I know it goes well over 14V but I have never been able to record a max. voltage.

Agreed. I haven't measured but I wouldn't be surprised that peak voltage immediately after start could be something like 14.7.