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diy solar

Inverter in the work truck

seneysolar

seneysolar

Solar Enthusiast
Joined
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645
Location
Michigan
Putting a 1000w inverter in my work truck and i have a couple things id like to accomplish. Not adding extra batteries and wont be using it without the truck running.

1. Monitor temp of the alternator. This is a GM single wire alternator, 100A powermaster. The inverter will mostly be used with the truck at idle and id really just like to keep an eye on the temp. Looking for a clean install temp meter of some sort and ways to attach probe to alternator. Anyone done this?

2. High idle the engine. Obviously alternators dont output max or cool themselves at low rpm. Theres tons of diesel options out there, but not much for gas trucks other than American Power Systems inc. Anyone use one? Anyone rig anything else up diy style?

I can get by without either one, but id like to be able to get sustained output or get in the ball park.

Yes i already though about cutting a stick to length and using the power seat to set rpm... 😂
 
justinm001 said:
1000w inverter on 100a alternator? You need to get a much larger alternator.
Click to expand...
I dont plan on maxing out the inverter. 1000w is just what i have laying around. Mostly charging drill batts while driving, work lights, fan.
I can monitor voltage and keep the large loads intermittent. Worst case is it will start dragging down my battery.
 
You should be fine, I ran power tools from a 2000w inverter & 70a alternator for years in my previous vehicle. I carried a spare alternator but never needed it.
 
Last edited:
I have a 2000 renogy pure sine in my Peterbilt 337 service truck. The truck has three yellow top optima group 31 batteries under the passenger seat. I mounted the inverter in the first bay behind the driver side. Ran 2 gauge cable, positive and negative from the batteries to inverter because I already had that size cable. Ran the 120V output to a few other bays and in the cab to charge laptop. I use it to charge milwaukee batteries, a microwave and even run 12/24 battery chargers on it for jump starting heavy equipment. The inverter stays on most of the time truck running or not and has never run the batteries down. Not sure what size the alternator is, factory size. If you are worried about running down your battery just add another with an isolator. I've inspected the power cables with a thermal camera while running heavy loads and they don't get hot so the 2 gauge is big enough for my application.
 
If this is a normal alternator expect to be able to pull 40-50% at idle and 70% during normal operation.

You should turn on lights, HVAC and such then after the cars warmed up put a clamp meter on the alternator to check the chassis loads. Subtract that from the 100a and you have an idea of how much power you have. You're not going to want to use the inverter for the first 15 minutes or so as it's recharging chassis.

You then can run your tools and such and monitor the voltage gauge on dash. If you can run everything at idle without a drop then you're perfectly fine to run while driving and not worry about overloading.

Alternator temps depend on if the vehicle is moving as lots of airflow around engine.

Idk of a temp sensor designed for alternators other than like a wakewpeed ws500. But I'd suggest getting a wireless BBQ temp sensor as it seems like the only similar use case. Make sure the temp probe goes above 200. 200F is the temp you can comfortably run an alt.

Alternators are strong and anything they can't handle the battery will pickup so if you pull 1000w it'll just drop voltage below 13v. If it gest below 12v then you'll have all kinds of issues and can break parts on your truck. They can also handle temps above 200f just not for a long time. On my MH I have 2 alts and huge DC converters. My massive alt isn't working so been using the small alt 70a (24v) and pulling as much as I can by turning on 1,2,3 converters depending if I'm driving or not and giving it time to cool.


As far as high idle, PTO, rabbit. I'd check your truck model and see if there's a way to just set the idle higher digitally.
 
Im fine with the inverter size and single battery, i realize its somewhat limited. My single optima yellow top is going on 7 years and im starting to get enjoyment out of torturing it 😂

Thank you @justinm001
thats what i was thinking. I had not heard anyone mention 200 deg as a threshold, seems low but makes sense. I had 275 in my mind.
 
seneysolar said:
Im fine with the inverter size and single battery, i realize its somewhat limited. My single optima yellow top is going on 7 years and im starting to get enjoyment out of torturing it 😂

Thank you @justinm001
thats what i was thinking. I had not heard anyone mention 200 deg as a threshold, seems low but makes sense. I had 275 in my mind.
Click to expand...
200 is the default wakespeed uses to start derating. Delco has pretty good stats on their alternators (both of mine are delco) and they're higher end industrial ones so a normal truck alt would be same or less.

Alternators by Model Family | Delco Remy

From brushless designs with fewer moving parts to remote sense to improve battery charge time, Delco Remy technology is second to none. We continue to leverage our experience to provide our OE and aftermarket partners with innovative solutions for today’s vehicle electric system challenges.
www.delcoremy.com www.delcoremy.com
 
one more thing when looking up specs. The Alt RPM is not the same as engine RPM. Usually double the speed. You can know this by measuring the crankshaft pully diameter and dividing by the alternator pulley diameter.
 
Firstly, you might be on the wrong forum as this is a solar forum, not a truck alternator forum.
Second, whats the big deal? hook it up and go. Figure out the duty cycle of your alternator, and use the inverter based on that. Of course you cannot use high amps continuously or the alt will burn up. A temp sensor will be good to tell you that you just burned up your alt. - kinda like your trucks water temp sensor = cold, normal, you just blew engine.
We have no idea how much power you need to use. Assuming something like a power tool and that it will be used for seconds at a time?? If you need lots of power for long periods then use a generator, or get batteries and solar as would expect you came to a solar forum that specializes on solar and batteries.
The answer is, get batteries and don't rely on an alternator, not a little one like you have.
Want another answer, go to an alternator forum.
 
0truck0 said:
Firstly, you might be on the wrong forum as this is a solar forum, not a truck alternator forum.
Second, whats the big deal? hook it up and go. Figure out the duty cycle of your alternator, and use the inverter based on that. Of course you cannot use high amps continuously or the alt will burn up. A temp sensor will be good to tell you that you just burned up your alt. - kinda like your trucks water temp sensor = cold, normal, you just blew engine.
We have no idea how much power you need to use. Assuming something like a power tool and that it will be used for seconds at a time?? If you need lots of power for long periods then use a generator, or get batteries and solar as would expect you came to a solar forum that specializes on solar and batteries.
The answer is, get batteries and don't rely on an alternator, not a little one like you have.
Want another answer, go to an alternator forum.
Click to expand...
It is a “vehicle mounted” systems section and large amount of posts on the first page deal with integration of an alternator into the charging systems. Maybe you are on the wrong forum, and just don’t like to be helpful.

I would get a clamp on amp prob and see what your vehicle draws from the alternator with everything on, then you know what you have to work with. It will be important with an inverter that size to limit the draw with such a small battery buffering the alternator. I charge at 100 amps from mine and am increasing that to 150-200amp.
 
0truck0 said:
Firstly, you might be on the wrong forum as this is a solar forum, not a truck alternator forum.
Second, whats the big deal? hook it up and go. Figure out the duty cycle of your alternator, and use the inverter based on that. Of course you cannot use high amps continuously or the alt will burn up. A temp sensor will be good to tell you that you just burned up your alt. - kinda like your trucks water temp sensor = cold, normal, you just blew engine.
We have no idea how much power you need to use. Assuming something like a power tool and that it will be used for seconds at a time?? If you need lots of power for long periods then use a generator, or get batteries and solar as would expect you came to a solar forum that specializes on solar and batteries.
The answer is, get batteries and don't rely on an alternator, not a little one like you have.
Want another answer, go to an alternator forum.
Click to expand...
I posted this in "vehicle mounted systems" because there are lots of folks on here recharging batteries and loading up their vehicle alternator. My question is about monitoring temp, as the high end alternator controllers do this to not burn up an alternator. Also lots of pickup campers use the alternator as their only generator so a high idle switch would be useful to get full output.
Just because i dont have a solar panel on my truck doesn't mean im in the wrong forum.
 
It is the positive diodes in alternator which are likely to fail. Not heatsinked to case like negative.

One car I had, wires to diodes were accessible from outside. I soldered on 3 more wires and ran them to heatsinked diodes outside.

If only alternators had temperature sensor on the positive heatsink and cut back output when hot, would be more bulletproof.

Maybe cobble a sensor onto it for display or to shut off inverter.
 
seneysolar said:
Putting a 1000w inverter in my work truck and i have a couple things id like to accomplish. Not adding extra batteries and wont be using it without the truck running.

1. Monitor temp of the alternator. This is a GM single wire alternator, 100A powermaster. The inverter will mostly be used with the truck at idle and id really just like to keep an eye on the temp. Looking for a clean install temp meter of some sort and ways to attach probe to alternator. Anyone done this?

2. High idle the engine. Obviously alternators dont output max or cool themselves at low rpm. Theres tons of diesel options out there, but not much for gas trucks other than American Power Systems inc. Anyone use one? Anyone rig anything else up diy style?

I can get by without either one, but id like to be able to get sustained output or get in the ball park.

Yes i already though about cutting a stick to length and using the power seat to set rpm... 😂
Click to expand...
A type K thermocouple should work. There are several types of ends available in different lengths to accommodate mounting. You would also need a low voltage power supply such as cigarette lighter or 9v battery to power the display.


 
seneysolar said:
Wow, looking good! I assume you are using a DC-DC charger? Redarc?
Click to expand...
Yes for now, I am going to change to Victrons new 50amp dc/dc and probably stack a couple for faster charging. I have 1/0 DLO charging cables rated at 260amps and can pull 100amps and still be safe with my current alternator.
 
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