Hooking up battery to alternator

R

roll_withit

New member
Hi all!

Trying to figure out how to hook up my aux battery to alternator.

Looking at some of the posts here it looks like maybe I could hook it in under the driver seat, but I am still a bit confused.

Would my hookup be under this box maybe?

Thanks!


Sent from my SM-G955U using Tapatalk
 
Axiom

Axiom

Mike from Florida Van Man
You'll have to run a couple of wires. You'll need to run one thicker gauge wire from the fuse box on the front of the engine battery to somewhere in the cab hooked up a battery isolator. Your aux battery also gets hooked up to the isolator. Amazon has 80amp battery isolators for about $25-$30, get one that's close to the amperage of your alternator. I chose underneath my passenger seat. You'll also need an ignition power source. I got lucky and had some cut wires underneath my drivers seat that i tapped into and ran through the conduit between the seats to the battery isolator. Once this is setup, start the van and test it out. Your aux battery should be charging to 13.8v so long as the van is running. I'd say the most important part is figuring out where you want to put the isolator and aux battery. I recommend keeping the isolator, aux battery, and any associated equipment close together.
 
Nautamaran

Nautamaran

2004 140” HRC 2500 (Crewed)
Ask your battery supplier what current the battery should be limited to during its “bulk charge” phase, and if it will survive 14 volts. You may need a small controller to limit/manage the charging flow, rather than simply joining it in parallel with your starting battery - or you might be fine, but ask the question.

-dave
 
autostaretx

autostaretx

Erratic Member
roll_withit said:
Trying to figure out how to hook up my aux battery to alternator.

Looking at some of the posts here it looks like maybe I could hook it in under the driver seat, but I am still a bit confused.

Would my hookup be under this box maybe?
Click to expand...
I have to admit, i don't recognize that box...

Yes, that's the area you could put an isolation relay

Which leads me to ask: what country are you in?
Axoim mentions using the fuse box that's at the battery ... but that doesn't exist in many non-US/Canada Sprinters.
Here's what he's talking about:



2nd question: where are you putting your "house" battery?
If it's under the passenger seat (like MB did it), there's a "tunnel" connecting the two seat bases, so it's relatively simple to push a thick wire through that to reach the battery.
From under the driver's seat, there's a trench that would lead up up to the main feed through the firewall, and you can probably squeeze your new wire through that.
Your photo shows that trench.

If you enter your VIN to https://www.datamb.com/ and fetch your "datacard" (what MB built into your Sprinter), you can look for the EK1 option. If you have it, you'll have this set of terminals on the wall of the under driver's seat area ...



NONE of those are suitable as a source of heavy current (for the charging), but if you use a coil-driven isolation relay, the "D+" signal is designed for driving that coil to cause the isolation relay to join the two batteries.

good luck
--dick
 
BrennWagon

BrennWagon

He’s just this guy, you know?
You can find pretty reasonably priced aux battery isolator kits on Amazon that include everything you’d need. I’m currently using this kit GS Power 150 amp Dual/Auxiliary... https://www.amazon.com/dp/B07DF94RPB?ref=ppx_pop_mob_ap_share and ended up with a couple of extra feet of the heavy wire. The van was made with a channel between the seat pedestals that allows the wire runs to be simple
 
Nautamaran

Nautamaran

2004 140” HRC 2500 (Crewed)
You actually CAN power a small (15 or 20 amp) charge controller from the 25 amps available from the EK1 strip’s red Bat(+) terminal, but you do still need an isolation relay between the batteries, triggered by the blue/yellow D+ wire (D+ is the alternator voltage, but is live only after the engine is running, NOT during cranking).

A 20 amp bulk charge would likely be ample for most 100 amp-hour lead-acid deep cycle batteries, which favour slower charge rates. A DC-DC Charge Controller in this capacity range would only cost about $20 at a solar-power supplier.

-dave
 
R

roll_withit

New member
autostaretx said:
I have to admit, i don't recognize that box...

Yes, that's the area you could put an isolation relay

Which leads me to ask: what country are you in?
Axoim mentions using the fuse box that's at the battery ... but that doesn't exist in many non-US/Canada Sprinters.
Here's what he's talking about:



2nd question: where are you putting your "house" battery?
If it's under the passenger seat (like MB did it), there's a "tunnel" connecting the two seat bases, so it's relatively simple to push a thick wire through that to reach the battery.
From under the driver's seat, there's a trench that would lead up up to the main feed through the firewall, and you can probably squeeze your new wire through that.
Your photo shows that trench.

If you enter your VIN to https://www.datamb.com/ and fetch your "datacard" (what MB built into your Sprinter), you can look for the EK1 option. If you have it, you'll have this set of terminals on the wall of the under driver's seat area ...



NONE of those are suitable as a source of heavy current (for the charging), but if you use a coil-driven isolation relay, the "D+" signal is designed for driving that coil to cause the isolation relay to join the two batteries.

good luck
--dick
Click to expand...
In US. And don't have that terminal on the passenger seat.

Will be placing the battery behind rear right wheel well.

Thinking I may just hook directly to alternator, run the cord back w/ some conduit & heat shield, then drill a hole in the floor near the battery for the cord to come up through

Sent from my SM-G955U using Tapatalk
 
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