400 Watt Solar Package W/ Alternator Charging

katimavik18

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Nov 19, 2021
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Hello everyone, i know this subject has been discussed earlier but i made a electrical blueprint of my version and i would like to have comments from people who tried it. Please take a look and tell me if there is some details that doesn't make sense.
Thank you very much. For now, i am not adding an inverter but surely will in the future.
I'm planning to build this for my van, a Dodge Promaster .
 

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rmaddy

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Nothing obvious jumps out to me after a quick review. But do keep in mind that with the battery wiring and battery fuse, your future inverter should not be over 2000W.
 

chrisski

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Just make sure the distance in the run doesn’t effect voltage loss from the battery. I did a one way run of 50 amps and got 5.2% with 4 AWG At 50 amps and 12 volts. Ampacity of the wire is fine. Also make sure you match up the proper breaker with a high AIC to the battery. I prefer class T fuses. Finally, the breaker at the solar panels is probably to big. In my head calculations put those two panels getting between 18 and 20 amps, so 40 amps is a little big.

I remember reading the specs for the renogy 50 amp charger that says it delivers a max of 25 amps from teh alternator and 25 amps from the solar panels for a total of 50 amps, but I’ve seen posts where people get the full 50 amps from teh charger from the battery.
 

acdoctor

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I believe you need to review all of the breaker size. You have #4 on a 70 and a 80 and #8 on a 100. Breakers and fuses protect wire.
 

katimavik18

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Nov 19, 2021
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Just make sure the distance in the run doesn’t effect voltage loss from the battery. I did a one way run of 50 amps and got 5.2% with 4 AWG At 50 amps and 12 volts. Ampacity of the wire is fine. Also make sure you match up the proper breaker with a high AIC to the battery. I prefer class T fuses. Finally, the breaker at the solar panels is probably to big. In my head calculations put those two panels getting between 18 and 20 amps, so 40 amps is a little big.

I remember reading the specs for the renogy 50 amp charger that says it delivers a max of 25 amps from teh alternator and 25 amps from the solar panels for a total of 50 amps, but I’ve seen posts where people get the full 50 amps from teh charger from the battery.
Thanks for your reply. I agree i'm pretty sure 40 amp is probably too big and my solar panel will not be able to give me that much. It's 25 amp from solar and 25 amp from battery in the best scenario . But, i have the breaker to close the solar and get 50 amp from battery if i want. What is the high AIC to the battery you are talking about ?
 

katimavik18

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Nothing obvious jumps out to me after a quick review. But do keep in mind that with the battery wiring and battery fuse, your future inverter should not be over 2000W.
That's my intend not to go higher than 2000 W if i add. Thanks for your reply
 

katimavik18

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Nov 19, 2021
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I believe you need to review all of the breaker size. You have #4 on a 70 and a 80 and #8 on a 100. Breakers and fuses protect wire.
Hello acdoctor and thanks, I'm pretty sure i have planned them as the product wanted me to do in the specs. How would you do it better ?
 

rmaddy

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Hello acdoctor and thanks, I'm pretty sure i have planned them as the product wanted me to do in the specs. How would you do it better ?
8AWG wire should, at most, be used for 40A of load and with no more than an 80A fuse.

The proper approach is to determine the max load. Then choose a wire size best for that load. Then you look at a good fuse chart and see what the max fuse size is for that wire size. You then pick a fuse that is between the load size and the max fuse size for the wire. Typically a fuse size that is 1.25 times the load size works out to be a good choice, as long as that is still less than the max fuse size for the wire. The fuse is to protect the wire, not the load. The fuse must be weaker than the wire.
 

katimavik18

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Ok so breaker problem is for my fuse block, i calculated that all my load are around 20 amps, it's ok to use the 8 AWG and the the max AMP for 8 AWG is 48 so i should go with the 40 A breaker . And i should be ok ?
 

rmaddy

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Ok so breaker problem is for my fuse block, i calculated that all my load are around 20 amps, it's ok to use the 8 AWG and the the max AMP for 8 AWG is 48 so i should go with the 40 A breaker . And i should be ok ?
For a total of 20A loads you would only need 14AWG wire but using larger wire is fine. It allows for some future expansion. You could use a 25A fuse for the 20A loads. But with the 8AWG wire a 40A fuse is fine, and again, it allows for some future expansion.
 

smoothJoey

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Nov 30, 2019
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Hello everyone, i know this subject has been discussed earlier but i made a electrical blueprint of my version and i would like to have comments from people who tried it. Please take a look and tell me if there is some details that doesn't make sense.
Thank you very much. For now, i am not adding an inverter but surely will in the future.
I'm planning to build this for my van, a Dodge Promaster .
The disconnect switch after the breaker off the battery positive terminal is superfluous.
As has already been mentioned the 100 amp fuse exceeds the ampacity of the 8 awg wire between the busbar and the distribution panel.
Looks like you plan to do chassis return to complete the circuit to the starter battery.
Make sure you have a good ground connection and that your alternator can handle the extra 50 amps load.
 

fratermus

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Mar 19, 2021
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Just make sure the distance in the run doesn’t effect voltage loss from the battery
The Promaster's battery is under the floorboards rather than engine bay, which cuts a few feet off the run. My aux batt is behind the driver's seat so the total run is about 6'. :)

I remember reading the specs for the renogy 50 amp charger that says it delivers a max of 25 amps from teh alternator and 25 amps from the solar panels for a total of 50 amps, but I’ve seen posts where people get the full 50 amps from teh charger from the battery.
the DCDC50 can pull 50A from either source when they are operating alone. The 25A/25A split only happens when both sources are active at the same time. The manual lays it out correctly but their website mucks it up.
Make sure you have a good ground connection and that your alternator can handle the extra 50 amps load
OP's Promaster has a 180A alt or optional 220A. As long as they are driving and not idling to charge the alt should stay happy.
 

smoothJoey

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the DCDC50 can pull 50A from either source when they are operating alone. The 25A/25A split only happens when both sources are active at the same time. The manual lays it out correctly but their website mucks it up.
I recently had the idea that to maximize alternator charging a normally closed relay could be inserted between the pv panels and the dc2dc charger.
The relay would be open when the engine is running.
Engine running = pv circuit off.
Engine off = pv circuit on.
 
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