Charge main battery from house battery via Body Builder Connector EK1?

MichaelGurevich

Active member
Hi,

I was looking over my build and see that I have this:

1599373857493.png

It got me thinking, I'm planning on installing a Nations Dual Alternator Kit, and powering a house battery from that, and running that house battery into a SPod Bantam X, which is a programmable switch box. What if I ran a line from the Bantam X into the Body Builder Connector, sending say... 10A into Terminal D+. Would that be the same as trickle charging the main battery from the house battery? Would that be a safe and useful thing to do?

Cheers,
Mike
 

RVBarry

2023 AWD 170 DIY CamperVan
Hi, how are you going to guarantee no more than 10A will flow, in BOTH directions?
 

MichaelGurevich

Active member
With the Bantam X, I would be able to specify how many Amps come out of each circuit.. so the circuit going to Terminal D+ could be set to 10A, or connect it to Terminal 30 and set it to 24 or 26A (they move by 2A).
 

FlaJoe

Active member
Momentum Van ran a commercial trickle charge from my lithium bank to the Mercedes battery so that when I am in storage and tied into a 30 amp it charges the engine battery. The lithium system is a Mastervolt system.
 

autostaretx

Erratic Member
For the record, here's the VS30 EK1 terminal strip:

EK1.jpg

and here is what the posts are connected to:

EK1vs30.jpg

To protect the expensive electronics from people doing silly things, the VS30 appears to have relays between the D+"signal" and the ignition On "signal" and those posts. So the relays should (no guarantees) protect the Sprinter from your plans.

For high current connections, there are spare connection points on the "pre-fuse" block that's tucked into the starter battery box next to the positive post. Your fuse allocation booklet calls it F150/1 . Position (2) is open for you to add a MIDI fuse.

wiring-F150_1 diagram.jpg

--dick
 

MichaelGurevich

Active member
Thank you so much for the great and detailed reply @autostaretx! Can you please say, do you think it's a worthwhile idea to pursue, and may I ask, where did you find those awesome docs?

Cheers,
Mike
 

MichaelGurevich

Active member
Momentum Van ran a commercial trickle charge from my lithium bank to the Mercedes battery so that when I am in storage and tied into a 30 amp it charges the engine battery. The lithium system is a Mastervolt system.
Thank you! It sounds like a great set-up they made for you :)

Do you happen to know where they connected the trickle charger to?
 

RVBarry

2023 AWD 170 DIY CamperVan
With the Bantam X, I would be able to specify how many Amps come out of each circuit.. so the circuit going to Terminal D+ could be set to 10A, or connect it to Terminal 30 and set it to 24 or 26A (they move by 2A).
Hi, I don't think that does what you think it does.
It's not going to throttle the current.
 

autostaretx

Erratic Member
Thank you so much for the great and detailed reply @autostaretx! Can you please say, do you think it's a worthwhile idea to pursue,
Personally, i would not use the D+ for that task (just as a bad habit).
The D+ is provided to allow you to operate a separate "isolation relay" (such as a Stinger or Cole Hersee)
and let that relay's beefy contacts handle the actual connections.
For just a 10 amp load, a typical DIN relay (which have 10 and 30 amp contacts) would work.
You could have that relay feed (either) the "ignition on" or "battery power" to your charging rig.

It's not a good idea to ask any circuit to provide its full fuse-rating power on a continuous basis. 75% of fuse rating is better.
(in the T1N, if you continuously draw the fuse rating from the front ash tray lighter socket ... it will melt the ashtray)
and may I ask, where did you find those awesome docs?
Various members have posted them here, over the years. I simply grab the ones i figure will be useful in the future.
(some i annotate, but those three were "as received")

--dick
 

MichaelGurevich

Active member
Either connecting the circuit to a fuse, which will blow if exceeded, or just adding to a digital counter to keep track of total load.
Hi :)

The thing I was looking at, and I forgot to mention, was the Bantam X app, which apparently is what enables the current limiting feature (https://www.4x4spod.com/bantamx_modular_w_led_switch_panel_84_battery_cables):

1599453830506.png

The "Programmable Current Limiting" line in the image above is what had me thinking about this. Does this seem like not the correct feature to look for in this instance?

Cheers
Mike
 

MichaelGurevich

Active member
Personally, i would not use the D+ for that task (just as a bad habit).
The D+ is provided to allow you to operate a separate "isolation relay" (such as a Stinger or Cole Hersee)
and let that relay's beefy contacts handle the actual connections.
For just a 10 amp load, a typical DIN relay (which have 10 and 30 amp contacts) would work.
You could have that relay feed (either) the "ignition on" or "battery power" to your charging rig.

It's not a good idea to ask any circuit to provide its full fuse-rating power on a continuous basis. 75% of fuse rating is better.
(in the T1N, if you continuously draw the fuse rating from the front ash tray lighter socket ... it will melt the ashtray)

Various members have posted them here, over the years. I simply grab the ones i figure will be useful in the future.
(some i annotate, but those three were "as received")

--dick
Thank you so much for your help and insight with this Dick, I totally appreciate it!

Do you think if I use Terminal 30, and set the Bantam X to limit the current to 16A (a bit less than 75% of the 25A allowed by Terminal 30), it would be a good place to send a trickle charger line, provided I send it to a beefy connector? There is something that's confusing me a bit, it seems that these terminals exist for outputting current to downstream consumers, and I am thinking of sending current into it. I don't know my electricity theory enough to know whether the current coming out of the EK1 and the current coming out of the trickle charger will somehow clash or otherwise interfere/interrupt each other?

Cheers,
Mike
 

RVBarry

2023 AWD 170 DIY CamperVan
The thing I was looking at, and I forgot to mention, was the Bantam X app, which apparently is what enables the current limiting feature (https://www.4x4spod.com/bantamx_modular_w_led_switch_panel_84_battery_cables):

The "Programmable Current Limiting" line in the image above is what had me thinking about this. Does this seem like not the correct feature to look for in this instance?
Hi, it sounds good, but it comes down to what it's really designed to do, and how it does it.
If its idea of limiting means it disconnects the load as soon as current is exceeded, then it's not what you need.
You'll probably have to ask the manufacturer.
I don't know my electricity theory enough to know whether the current coming out of the EK1 and the current coming out of the trickle charger will somehow clash or otherwise interfere/interrupt each other?
Whichever battery system has a higher voltage/charge level will feed power to the other system.
After camping, your house batteries will be low, and the chassis battery high, so current will flow the wrong way.
This could damage the device if it's not designed to have two power systems connected.

Have you seen
the trickl-start chargers,
A dual-output solar controller,
Or a $20 solar cell/charger combo?


 

zpram

Member
For the record, here's the VS30 EK1 terminal strip:

View attachment 152477

and here is what the posts are connected to:

View attachment 152479

To protect the expensive electronics from people doing silly things, the VS30 appears to have relays between the D+"signal" and the ignition On "signal" and those posts. So the relays should (no guarantees) protect the Sprinter from your plans.

For high current connections, there are spare connection points on the "pre-fuse" block that's tucked into the starter battery box next to the positive post. Your fuse allocation booklet calls it F150/1 . Position (2) is open for you to add a MIDI fuse.

View attachment 152481

--dick
Curious on how you tapped in with a midi on label 2? I'm assuming this is not your pic because I don't see a midi. Does 3 ->2 fit a midi? I've read this in a similar post but can't seem to find it.
 

autostaretx

Erratic Member
Curious on how you tapped in with a midi on label 2? I'm assuming this is not your pic because I don't see a midi. Does 3 ->2 fit a midi? I've read this in a similar post but can't seem to find it.
You are correct, it's not my photo ... i have a T1N, not NCV3 nor VS30, so i can't just run out and look (otherwise i would)
People were creative ... here's another "solution":
BusBarAdded.jpeg

--dick
 

tscholman

New member
Thank you so much for your help and insight with this Dick, I totally appreciate it!

Do you think if I use Terminal 30, and set the Bantam X to limit the current to 16A (a bit less than 75% of the 25A allowed by Terminal 30), it would be a good place to send a trickle charger line, provided I send it to a beefy connector? There is something that's confusing me a bit, it seems that these terminals exist for outputting current to downstream consumers, and I am thinking of sending current into it. I don't know my electricity theory enough to know whether the current coming out of the EK1 and the current coming out of the trickle charger will somehow clash or otherwise interfere/interrupt each other?

Cheers,
Mike
I connected a Victron Energy Orion-Tr IP43 24/12-Volt 5 amp 60-Watt DC/DC Converter, Non Isolated to Terminal 30 and added a switch to manually turn it on an off. Since it's only 5a, I thought it would be find as a trickle charger on that post. I had the switch off when I reconnected the chassis battery, so there was no input current, and it blew the 25a fuse. Wondering if that's an issue with that particular converter receiving backflow somehow, or if it's an issue with connecting to terminal 30? I am considering changing it out to a Victron Energy Orion-Tr Smart 24/12-20A (240W) instead, just wanted some input as to why the fuse may have blown before I do.

Tim S.
 

Top Bottom