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I thought you wanted to measure the alternator, not the battery
I thought you wanted to measure the alternator. Like I said before, power for the accessories comes from the alternator, not the battery.
I'm confused. Either you didn't ask the right question, or you have a fundamental misunderstanding of how everything works.
If you had a factory standard van, I could help you determine your alternator output. However, since yours has been converted, I have no idea what you have under the hood. If you really want to monkey with your system then I highly suggest hunting down schematics.
Alternatively, just go with it. It's a bit difficult to predict how the system will behave since there's a few variables involved, but I think that 20A is not that much. Just see how things go. If your alternator isn't up to the task, you will see the voltage sag a bit, and you'll know that you need to upsize.
haha yeah I'm learning and the internet is my book. I have been reading forums, watching videos etc on converting vans to live in and solar setups. There are thousands of experts out there that all have different opinions and knowledge on how stuff works, should work or be done. Insulation was a fun one.
Anyway, several resources including the place I got my batteries from said to see the real output of my alternator, hook up a meter (clamp/amp meter) to the positive from alternator to battery. So I did. One video I saw I think was of a jeep and a guy showing how to test. He did the same and when he turned on accessories, the current jumped.
From my understanding the only thing directly connected to the alternator is the vehicle battery. Multiple items like in mine can be connected to the + of the battery though. Basically making the + post like a terminal block.
There are a couple ways of charging house batteries off an alternator. One is using a BIM and another is B2B charger are the two I looked at.
I guess I got on here for help with my van which bare bones is an express 1500. I didn't want to rehash my whole design as I have done this over and over with part vendors and other van conversion resources. The big difference is most of these is the vehicle one is working with. Some of these parts are dependent on what my van has to offer so to speak. Like my 145a alternator. Depending on what it can output or handle is what I base on if I can use a 20a or 40a B2B, or would be better off with a BIM. I don't want to damage/over work my alternator. But if it can handle sending 40a to charge my batteries safely, then that would allow me to charge them a lot faster. This would be beneficial in that a lot of my drives would be short, 30 mins or less and probably 2 drives most days. As you stated 20a is not that much and I went with that for the safe route.
The battery tech said I could hook there batteries directly up to my vehicle battery and then see how much they might draw, but it seems they came fully charged as I didn't see them pulling any current.
But yes, I'm am trying to learn and understand all this while doing it myself and not pay a lot to have someone else do it. I have seen what others have done out there and I'm like how in the world did that ever work . I know I have the ability, just need to get to where I feel confident in the info I have gathered. My downfall is sometimes I research way way too much while others read a few things, try it and if it works they are like cool, awesome.
Look, read the pages one through five that linked. Your generator may have a "turn on" wire which is really easy to ascertain. You just look at the back of it. It is either there or it is not. From what I recall, without re-reading... the generator gets controlled by that wire. As for the opinions and diatribe that you come across on these threads, that's all they are. Opinions and diatribe. Get schematics and read.
Alternator is only going to put out what the load requires. If you are not running all your lights, battery is fully charged, you will only see the output versus the load.
which lights? A standard dome lamp only draws around half an amp.
Originally Posted by zebo51
AC
The air conditioning compressor is driven by the accessory belt off the crankshaft. It's not an electrical device. Unless you're talking about the fan motor.
Originally Posted by zebo51
I would expect to at least see over 10a
I think it's entirely possible for a vehicle to run normally using less than 10A.
Originally Posted by zebo51
my van which bare bones is an express 1500
OK. You said it was modified by Sherrod.
Alternator makers have purpose built bench equipment for testing maximum performance. I think measuring things with your clamp meter isn't going to produce information that is particularly helpful to your end goal. At idle your alternator is CAPABLE of generating around 30A max, and the 140A figure would be at around 6000 RPM. That is only IF you're accessories are demanding that much, which would be unusual. Over a typical driving cycle, available power is going up and down, and so is demand. If you're only measuring a few amps then you have plenty of reserve. I think you're getting mired by details, when you could be getting your hands dirty and getting practical and productive results.
Sorry I kind of abandoned this thread. I have it all working and have done a few trips since last fall. Going to hit the road full time end of this month, but I think all is good solar wise. When I turn on my B2B charger, it pulls 20amps exactly which is what it maxes out at. Attached is a picture of my setup for it. Still going to add a few more accessory items, but the main items are there.
Very tidy installation- I like it. Any more information you could provide would be great, like if you have a schematic.
You have a cable running to the alternator?
Looks like you've got two Li batteries in parallel. How much $$ do those go for?
I see an inverter, charger, and I guess the blue box is the solar controller.
Looks like a manual switch, some fuses, a fuse block...
I really like those distribution blocks. Do you have any info or close-ups on those?
I went off another van builds schematic. Faroutride has a great build and provide many details. I went off their schematic as a base and changed it to fit my needs, so cable sizes, fuses etc are all selected to work with my items. https://faroutride.com/electrical-system/
Kinda of a quick summary:
4AWG from van battery back to my house batteries. Renogy 20a DC-DC charger. I put it on a manual switch instead of ignition. Used a red illuminated switch and so far haven't ever forgot and left it on when the van is off
Two Battleborn LiFePO4 100ah batteries in parallel.
Two Renogy 160W 12v mono panels on the roof going to a Victron Smartsolar MPPT 100/30.
Victron BMV-712 battery monitor. Both this and the smartsolar are bluetooth, so I can see/monitor power both in/out.
Renogy 1000W 12v pure sine wave inverter.
One main manual switch off the house batteries.
The terminal blocks are nice, Blue sea bus bars. They come in a variety of stud sizes and amps.
Then I also used the blue sea 12v distribution fuse block.
Right now my 12v powered items are:
Dometic CFX 65DZ fridge/freezer
Maxx air Deluxe Fantastic fan
LED lights
Couple 12v sockets
Water pump
120v items:
Toaster - gotta have toast with my eggs and bacon
computer
TV
So really my power requirements are not that high. If I was just sitting with only 12v items and no sun, I could go about 9 or 10 days. The LI batteries are great since you can drain them 100% without worry. Although I don't think I have dropped below 60ish %.
I also have a propex heater and regular two burner stove fed by a 20lb propane tank located in back inside a vented locker.
I might do a thread for my build once I get a few more things finished.
October 1st, 2019, 8:43 AM
. I know I have the ability, just need to get to where I feel confident in the info I have gathered. My downfall is sometimes I research way way too much while others read a few things, try it and if it works they are like cool, awesome.
