12 v for fridge and water pump.

[TravelingTales]

Hello all!

Curious to find some information on how to supply the circuit board power to our norcold. And supply 12 v to the water pump properly. I understand 12v, just would like to be led to some information on how other people have supplied theirs with 12v. As far as swithces for the water pump (kind), relays, extra battery bank for the fridge and water pump? We have an onan 7500 watt generator on board and two 12 volt batteries for starting and running the bus so far. Any help is highly appreciated! Thanks 😁

[john61ct]

Blue Sea makes great little distribution panels, just run off the House bank after the master fuse/breaker maybe a master isolation switch.

Each major device can get its own circuit, wires sized and fused appropriately.

[david.dgeorge07]

Should have a dedicated house battery or bank. Generally try to leave the starter bank alone for your house loads.

[TravelingTales]

Originally Posted by john61ct

Blue Sea makes great little distribution panels, just run off the House bank after the master fuse/breaker maybe a master isolation switch.

Each major device can get its own circuit, wires sized and fused appropriately.

Thanks. That gets me understanding what direction to go right after the batteries. And if I need a separate battery bank. My only thing I will need to look for now. Is the switch for the water pump. When turning the shower or the sink on.. I like your idea of a master isolation switch.

[ol trunt]

If you choose to directly switch a 12v load be sure to use a 12v switch rated for the proper amperage. If you use a switch designed for 120v you will soon learn that they won't be able to handle the amps found in a 12v system. That said, the 120v switches seem to last if they are used solely to activate a 12v relay which then conducts the 12v load.
Jack

[john61ct]

Again, Blue Sea for high-current battery type switches.

There are others of course, but this sort of gear best not to try to save nickels.

And 100% yes you need a House bank isolated from Starter.

Deep cycling is an entirely different category of battery, using a Starter for that will quickly murder it and leave you stranded out in whoop-whoop.

[HazMatt]

Appreciate the confirmation!

Originally Posted by john61ct

Again, Blue Sea for high-current battery type switches.

There are others of course, but this sort of gear best not to try to save nickels.

And 100% yes you need a House bank isolated from Starter.

Deep cycling is an entirely different category of battery, using a Starter for that will quickly murder it and leave you stranded out in whoop-whoop.

I've already bookmarked several Blue Sea blocks in my, "narrow-down-to-one," category.

[john61ct]

I meant for bank switches too, different product category

[HazMatt]

My bad. Quoted the wrong entry from you.

[david.dgeorge07]

For switching your water pump a lot of tank monitor panels have the pump switch included. It makes for a nice unified way to deal with the tanks and pump.

[david.dgeorge07]

From somewhere in my build...

[TravelingTales]

I really appreciate all of the input. My main question now is. Since I will have two battery banks. One for starting and one for house. And if I am only using it for water pump and circuit board power for the fridge... What size battery bank should I consider for a house bank. Also, how to charge that bank? Basically have two banks and be able to switch the two back and forth to charge from the alternator? Thanks!

[ol trunt]

My .02 cents worth. Buy a pair of deep cycle 6v golf cart batteries to use for your house needs. Install a three stage battery to battery charger to keep them charged. Never even consider using your start battery for house purposes.

I am completely happy with my B to B system as it lets me reach camp with a properly charged house battery and no need to immediately crank up the genny. The unit I chose is this: https://www.ebay.com/sch/i.html?_fro...B1230&_sacat=0.
Jack

[david.dgeorge07]

Originally Posted by TravelingTales

I really appreciate all of the input. My main question now is. Since I will have two battery banks. One for starting and one for house. And if I am only using it for water pump and circuit board power for the fridge... What size battery bank should I consider for a house bank. Also, how to charge that bank? Basically have two banks and be able to switch the two back and forth to charge from the alternator? Thanks!

Will you ever run lighting or an inverter? If you only ever power the pump and the fridge computer that won’t take much, but most people end up with a lot of 12V stuff in the mix.

Another thing to consider in battery purchase is where it will be stored. If in a bay somewhere, flooded lead acid is fine. If inside you need AGM and/or a well vented battery compartment built.

One, or a pair of deep cycle marine batteries run in parallel from Walmart or wherever would probably do you fine for what you are talking about, but make sure you don’t outgrow your system right away.

I used to use an automatic isolator that would open a relay when alternator was running and charge the house battery. I still have it and would sell it for a deal if you’re interested. It’s a good unit but I went with a manual marine switch to give me more control over when I was loading the alternator since I have a big inverter and air conditioning running off my batts.

This is the model.

https://www.amazon.com/Smart-Battery...gateway&sr=8-3

[TravelingTales]

Ok, thanks for the help big time you all. Old trunt, I really like your idea of it. And everyone's input has really helped my a bunch. Another question I have is. When you turn the water on. What kind of switch is telling the water pump to turn on. That is about the last thing I need to clear up in my head. Thanks!!

[CMORGANSKOOL]

Originally Posted by TravelingTales

I really appreciate all of the input. My main question now is. Since I will have two battery banks. One for starting and one for house. And if I am only using it for water pump and circuit board power for the fridge... What size battery bank should I consider for a house bank. Also, how to charge that bank? Basically have two banks and be able to switch the two back and forth to charge from the alternator? Thanks!

I would recommend a min of 200ah battery bank to run your fridge and pump without worries of running out of charge while out and about.

[Sleddgracer]

Originally Posted by TravelingTales

Ok, thanks for the help big time you all. Old trunt, I really like your idea of it. And everyone's input has really helped my a bunch. Another question I have is. When you turn the water on. What kind of switch is telling the water pump to turn on. That is about the last thing I need to clear up in my head. Thanks!!

the RVs that I've been involved with have a switch on the countertop next to the sink - when you want water you turn the switch on

[Triskite]

We've been full-timing for about 4 years now. Pretty important tip for the water pump:

When the pump can't get enough water (e.g. tank gets too low) it will turn on - AND STAY ON. The extra frustrating things about this are:
1. It can damage/break your pump if you don't manually turn it off
2. Normally you can hear the water pump, it's pretty loud, but when it runs 'dry' it's super quiet and hard to hear
3. It's a waste of power and can kill your battery (this is the only device we use the vehicle battery bank for, so it's especially a nuisance for us)
4. Even if you install/build a water tank monitor, this can still happen to you depending on if you're parked on a slope/grade, etc.

Fortunately, I found a 10-minute $15 solution recently:
An open-source 12-60V wifi smart relay with power monitoring & local web interface:
https://shelly.cloud/shelly-1pm-wifi...me-automation/
(also available on amazon)

Just put that between your fuse & the pump and you can super easily keep an eye on your pump and turn it on/off as needed (from your phone or a physical switch that plugs in) for maintenance/upgrades/etc. or when you run out of water.

Hope this info doesn't complicate an already confusing time in a young skoolie's build, but I wish these had existed when I first did our wiring and someone had told me about them.

As a bonus you can use power consumption of the pump to estimate how much water is left