diy solar

diy solar

1997 Isuzu NPR build

You are exactly right about not exceeding the recommended voltage. And unlike a conventional agm, these TPPL pure leads actually LIKE healthy charge current.

Second thought from a racer standpoint - since you are in a truck, and have less concern about weight and size, perhaps do at least a +1 on the Odyssey. Ie, go from the PC-680 and upsize it to the PC-925. Now you'll get 6 tries at starting instead of 3.

Or, if I put my battery-salesman hat on, I just wonder about a "Plan B". That is, if your LFP bank has an issue, and you are stuck out in the boonies, with only the PC-680 serving as a backup, you might only get 2 hours of life for your cab electronics to work while waiting for rescue. Less if your lights are on trying to fix something. Step over to the counter and let's talk about something much larger in our line. Help yourself to our free coffee! :)

Heh, looks like Odyssey changed the model nomenclatures on me behind my back while I wasn't looking. It took years to memorize those.
 
You are exactly right about not exceeding the recommended voltage. And unlike a conventional agm, these TPPL pure leads actually LIKE healthy charge current.

Second thought from a racer standpoint - since you are in a truck, and have less concern about weight and size, perhaps do at least a +1 on the Odyssey. Ie, go from the PC-680 and upsize it to the PC-925. Now you'll get 6 tries at starting instead of 3.

Or, if I put my battery-salesman hat on, I just wonder about a "Plan B". That is, if your LFP bank has an issue, and you are stuck out in the boonies, with only the PC-680 serving as a backup, you might only get 2 hours of life for your cab electronics to work while waiting for rescue. Less if your lights are on trying to fix something. Step over to the counter and let's talk about something much larger in our line. Help yourself to our free coffee! :)

Heh, looks like Odyssey changed the model nomenclatures on me behind my back while I wasn't looking. It took years to memorize those.
LOL

You are correct in the weight not being an issue but I am pretty limited in space. The original battery sat on the frame rail just ahead of the passenger tire. Now with 40s the tire hits the battery box under compression and a left turn. Moving the battery to the rear between the frame rails eliminates interferences but I am still limited in space.

Im really not worried about power issues. I will always have a generator and an independent battery charger. I guess this will be my excuse to buy an OBC-20A
 
Been busy building the truck mechanical and box for the truck so the electrical has been a bit neglected but a month or so ago I realized I had missed a detail in my system.

My plan is to have the two electrical systems (vehicle and "house" system) integrated. Some have told me it is a bad idea but I think they just have not considered all the nuances. I am yet to have anyone explain why it is a bad idea but if you have concerns please tell me! I discovered one but have found a cool component to fix it.

The goal is to have basically unlimited power for the winches on the truck. The winches are powered by 16 280ah cells (12v) house batteries which when fully charged would power the winches for a full hour of winch time. I was originally planning to have the two systems separate and independent with the exception of a small DC-DC charger charging the house batteries. Part of the system is 2 Victron BP220 which were to be used to simply isolate the 12v going out to the winches so that there was no 12v going out to the winches unless I turned them on but also the BMS would turn them off while winching if the battery was low.

I misread the BP220 information. I thought the BP 220 would not allow power to flow backwards through them.
Turns out, they will allow current to flow backwards through them, and, it will destroy them. They must not have current back flow through them.

Before I realized this, I redesigned the system (thinking the BP would prevent current flowing back through them). I decided to tag the + and - from the two systems together and because the BP 220s would (I thought) prevent current from charging the house batteries via that circuit the only route current would have back to the batteries would be through the DC-DC, preventing overloading the alternator. The benefit of doing this was that I now dont really need a starting battery (I am still using a very small one https://www.odysseybattery.com/products/ods-agm16l-battery-pc680/). Also the alternator would contribute to winching current without having to go through the DC-DC.

Fast forward to finding out the BP will allow a reverse current, destroying them, and I went on the hunt to see if I could still do this and I found this!:

20210805_213143.jpg
Its a 300A diode. I had no idea they made them that big! The current for the winch will not travel through the diode. It has a .3v drop across it which for winching for a few minutes would generate to much heat. The current for starting the truck will go through it and as it is such a brief event, nothing like winching, the voltage drop isnt an issue. There is also the small battery that will contribute to that effort.

Now everything can work as I had planned, except the alternator contributing to winching without going through the DC-DC, but so what, there is still 30 amps getting there and less stress on the alternator.

Let me know if Im missing something!
 
WOW I'm so jealous of this build. I would love to do this instead of the standard promaster of like setup.
 
WOW I'm so jealous of this build. I would love to do this instead of the standard promaster of like setup.
LOL
2 years into it Im wishing I had done something a little more simple. :) It should be a lot of fun when its done though.
 
Interesting idea on the batteries. Mine is based on the separate (main and house) systems, but I'm working with a different electrical beast with 12v and 24v. When I get to a winch it will be 24v as well but running off the main batteries. Curious to see how this works out!

I'm three years into mine... :rolleyes: but starting to see some light at the end of the tunnel...
 
Interesting idea on the batteries. Mine is based on the separate (main and house) systems, but I'm working with a different electrical beast with 12v and 24v. When I get to a winch it will be 24v as well but running off the main batteries. Curious to see how this works out!

I'm three years into mine... :rolleyes: but starting to see some light at the end of the tunnel...
I almost did 24v house battery simply because I wanted 24v winches to reduce the conductor losses. Where I am, getting 24v replacement parts in a reasonable time frame is not in the cards but it did open up the possibility of starting off the house batteries. 4/0 cable isnt cheap but it will keep the losses in the 10'run from the house battery to the front winch to a minimum.
 
LOL
2 years into it Im wishing I had done something a little more simple. :) It should be a lot of fun when its done though.
I can relate on different levels of projects to this. I always end up with a project that gets over complicated thinking of everything until its in use then you realize if could have been much more simple and saved lot more money.
 
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