Noobie electrical question/clarification - fuses & power

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brobov

New member
Got a quick question for someone who may be able to explain and simplify things a bit for me (also pictures, I love pictures)


I am adding a back up camera and monitor to my van along with other minor electrical equipment for driving, all of this equipment should be running from engine/alternator power when the van is on.

How can I properly, correctly and safely tap into the van power & add a small fusebox for additional electrical equipment?

- I believe I need to use Terminal 3 on the EK1 connectors, is this correct?
- For adding a fusebox post the EK1 connector (or elsewhere), do I need to add a fuse (15amp?) before the fuse box?
-Ground should be to the body/seat pedestal

Any additional advice, hints or threads that are recommended to look over?


Somewhat related: I am in the beginning stages of learning and understanding all the complexities of the electrical systems, I am planning on having 150-200 AH of lithium power that I would like to charge from the alternator and solar and also use the house batteries to allow to charge the starter battery, I was considering using the sterling B2B charger but that appears to only work 1 way, should I consider using the bluesea ML-ACR instead?

For reference I have a 2016 I4 sprinter with the M60 (250A) alternator


Thank you!
 
autostaretx

autostaretx

Erratic Member
Here is where Mercedes intended you to "tap in" for reasonable loads:

PowerTaps.jpg

The fuses are on your seat-side fuse block.
It never hurts to add smaller fuses throughout your additions (limits the outages when they pop)

--dick
 
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DieselFumes

DieselFumes

2015 4x4 2500 170 Crew
brobov said:
How can I properly, correctly and safely tap into the van power & add a small fusebox for additional electrical equipment?

- I believe I need to use Terminal 3 on the EK1 connectors, is this correct?
- For adding a fusebox post the EK1 connector (or elsewhere), do I need to add a fuse (15amp?) before the fuse box?
-Ground should be to the body/seat pedestal

Any additional advice, hints or threads that are recommended to look over?
Click to expand...
It depends on the load you want to use. The EK1 terminals are only made for smaller loads. Here's something I wrote on tapping in to the battery. We have the aux battery, but the article still applies even if you don't.

Your fuses are designed to protect the wire, not the device attached to the wire. So if you add a fuse before the fuse box, size it for the wire you run between the EK1 terminal and the fuse box. Then, just use the correct size fuses in your fuse box for each of the runs beyond. If you used a 15 amp fuse on the wire to the fuse box but then tried to pull more than 15A on the consumers from the fuse box, you can guess what's going to happen.

This intro to 12v systems in van conversions may be too basic for you, but it might be worth a look.

brobov said:
Somewhat related: I am in the beginning stages of learning and understanding all the complexities of the electrical systems, I am planning on having 150-200 AH of lithium power that I would like to charge from the alternator and solar and also use the house batteries to allow to charge the starter battery, I was considering using the sterling B2B charger but that appears to only work 1 way, should I consider using the bluesea ML-ACR instead?

For reference I have a 2016 I4 sprinter with the M60 (250A) alternator
Click to expand...
if you're going to wire something into the system to charge from the engine, here are some ways to do it. Because you want to use lithium, you probably DO want to use something like the Sterling B2B because otherwise your lithium battery won't get a proper charge and could even be damaged by the van's electrical system. Also, the newer Sterling B2B chargers have a setting where they will tolerate charging while the alternator voltage is lower (they call it "regenerative braking mode"). There's been some talk on this site about the I4 engine exerting a lot of control over the alternator and (perhaps) running it at lower voltages. I don't have that engine/alternator so I can't tell you for sure whether this is the case, but the Sterling lets you get around that.

When you way "work one way" do you mean being able to jump the starter from your house battery? Yes, that is a limitation of the Sterling. You pretty much don't ever want the house battery to be charging the starter battery in any other situation.
 
B

brobov

New member
DieselFumes said:
It depends on the load you want to use. The EK1 terminals are only made for smaller loads. Here's something I wrote on tapping in to the battery. We have the aux battery, but the article still applies even if you don't.

Your fuses are designed to protect the wire, not the device attached to the wire. So if you add a fuse before the fuse box, size it for the wire you run between the EK1 terminal and the fuse box. Then, just use the correct size fuses in your fuse box for each of the runs beyond. If you used a 15 amp fuse on the wire to the fuse box but then tried to pull more than 15A on the consumers from the fuse box, you can guess what's going to happen.

This intro to 12v systems in van conversions may be too basic for you, but it might be worth a look.



if you're going to wire something into the system to charge from the engine, here are some ways to do it. Because you want to use lithium, you probably DO want to use something like the Sterling B2B because otherwise your lithium battery won't get a proper charge and could even be damaged by the van's electrical system. Also, the newer Sterling B2B chargers have a setting where they will tolerate charging while the alternator voltage is lower (they call it "regenerative braking mode"). There's been some talk on this site about the I4 engine exerting a lot of control over the alternator and (perhaps) running it at lower voltages. I don't have that engine/alternator so I can't tell you for sure whether this is the case, but the Sterling lets you get around that.

When you way "work one way" do you mean being able to jump the starter from your house battery? Yes, that is a limitation of the Sterling. You pretty much don't ever want the house battery to be charging the starter battery in any other situation.
Click to expand...
Thanks for the reply! Big fan of your build and all the write ups you have posted, :bow: I've learned a lot, mad respect!

My planned load for the EK1 is definitely on the lower end, camera + additional monitor to begin with. Keeping the vast majority of my electrical load to the house batteries.

Regarding the B2B charger, and the house & starter batteries. It's pretty much what I expected then that I will need to invest in the more robust charger in order to make sure all the batteries and electronics on both side of the charger remain happy #$printerlife.

I am not sure how the M60 optional Alternator changes things for my van, its supposedly a 250 amp alternator, not the standard one that comes with the I4, now sure how it changes things for me but it sounds like it should only help with having a beefier alternator.

Regarding starter battery charging: Would something like the 'Trik-L-start' be a wise gadget to invest in to keep the starter battery from getting drained and also topped off during periods of extended parking? I recently ran my starter battery down to the point where the voltage was too low for it to start, the cascading mountain of low voltage ECU errors that followed makes me really not want for that to happen again.
 
DieselFumes

DieselFumes

2015 4x4 2500 170 Crew
The bigger alternator should help with overall output, but I really don't know what the alternator management stuff does on that I4 engine. There are lots of rumors. I guess you'll find out!

The tricklstart isn't something I've used, but I have considered it for the same reasons as you. Even though you have the larger alternator, you don't have a larger starter battery!

Overall, the more you can move across to your house batteries the less load you'll be putting on your starter battery while the engine isn't running. Stuff that's only on when the engine is on (camera, monitor) is obviously less of an issue to have attached to the starter battery. We have an electric step that runs even when the engine is off, and that definitely draws some power if we're in and out of the van a lot.
 
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