Non Solar Options For Charging House Batteries ?

Bravo30

Well-known member
Vehicle: 2013 Mercedes Sprinter 170 WB Hight Top with an auxiliary battery set-up

We will be taking a road trip out west in a few months (Phila (E.A.G.L.E.S.) to Arizona and beyond). We plan on staying at campgrounds and boon docking with motel stays mixed in between.

I don't want to fully convert the van since this is only going to be a 2 month long trip and I could possibly need the van in cargo form afterwards. I plan on paneling and insulating the inside. adding 2 roof vents, water storage system, compost toilet and propane instant hot water heater for showers and cooking and a few LED light bars. these are our basic needs for now.

My problem is what to do with the electrical? again, i don't want to heavily modify the van. Before this trip we did a lot of weekend van camping and plan to continue. Although we don't use much power i would still like to have it on hand (be prepared) i think 400AH should be fine with room to spare for future considerations. the only things we would need power for are the interior lights, fans, Fridge, water pump possibly and charging phones/lap tops. ideally i would like a system that charges via the vans alternator but its a bit overwhelming trying to piece together the components.



thoughts?
 

comptiger5000

Adventurer
Solar doesn't have to mean permanent mods. Hook up a charge controller in a way where you can remove it later if desired. And use portable panels that can sit near the van and be plugged in, then folded up for traveling.
 

WOODY2

Adventurer
CTEK 250S with a 100 watt panel. The CTEK will charge at 14.4 while you drive and also act a solar controller
 
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WOODY2

Adventurer
CTEK 250S with a 100 watt panel. The CTEK will charge at 14.4 while you drive and also act a solar controller when needed.
 

Bbasso

Expedition Leader
400Ah?
Geezer that is a fair amount... and would take a fair amount of time to charge up...
What is your current draw?
Either way I'd suggest the https://www.bluesea.com/products/76...rging_Relay_with_Manual_Control_-_12V_DC_500A
Because you can charge while driving and idling, say if you need to run a high draw appliance... without depleting the house batteries.

But solar can be a temporary install and provide a good amount of power, while working with the 7622ACR.
 

Bravo30

Well-known member
ok, heres my preliminary plan after a few months of research.

im going to stay away from using the auxiliary battery in the sprinter. i don't want to mess with the Mercedes electrical system if i dont have to.

Purchase 2 Deep cycle AGM batteries wired in parallel. total AH will be around 400 giving me 200 usable hours. Next i will purchase either a Ctek D250s or a unit from Sterling Power (still undecided on which one/model) to be connected to the batteries, the alternator and a portable solar panel (panel size still undetermined) Next off of the batteries is an on/off switch then a 12v fuse panel and then another on/ff switch and a power inverter. from the 12v panel i will run all of my lights an 12v outlets. nothing connected to the inverter. i probably dont even need the inverter but it is an option and i like options.


questions:

1- do i need a battery monitor ? my gut says YES. if so where in line should i install it ?


thoughts ?
 

Bravo30

Well-known member
400Ah?
Geezer that is a fair amount... and would take a fair amount of time to charge up...
What is your current draw?

for now just a Dometic fridge and lights, iphone charging etc ... but we may add an electric blanket in the future so i want to build in some room for expansion.
 

rruff

Explorer
CTEK 250S with a 100 watt panel. The CTEK will charge at 14.4 while you drive and also act a solar controller

Pardon my ignorance, but do you really need "dual input charging"? What if you hooked the alternator and solar to the same input on the charge contoller?
 

Bravo30

Well-known member
Its a good idea...
Now decide what sort of battery monitoring you want to do. I keep it simple, just monitoring voltage & current in both directions.
Lots of mouseclicker option freaks will further monitor watthours, temperatures & all sort of parameters to rival a Spaceshuttle, with wifi touchscreen no less.

im with you on that !! i have a problem overthinking things. my ideal monitor would display a smiley face and sad face. anything more will keep me up at night.
 

rruff

Explorer
Potentially this could work, albeit daft.

Thank you, that makes sense. Yes, would need to make sure the alternator did not exceed the controller max amps. But this would be true of any controller, yes? The CTEK unit only allows 20a unless you get the "smartpass". Maybe they limit to 20a, rather than shut off? It would probably make more sense to wire directly from the alternator to battery...?

I'm going to use a LiFe battery (200ah). I've heard that alternators will only supply their max amps for short periods, then will reduce output to prevent overheating. Does that sound right? At any rate, the battery could take 200a, and the alternator would not overcharge it because the battery is 14.4v when full. I understand that AGM is also a little higher voltage than regular LA?
 

ajmaudio

Adventurer
on the battery monitoring, I do suggest more than just voltage and current in or out. This will not give you accurate gauge of actual battery capacity remaining. If your going to monitor a battery why would you not want to know how much capacity you actually have. Voltage is not a reliable way to measure this at all while a battery is in use so my suggestion is to use something that is a tad smarter. You dont need touch screens etc, something like the victron bms700 or a trimetric from bogart is plenty and very useful. I have a trimetric on my camper and wouldnt consider not having it.
 

Bravo30

Well-known member
on the battery monitoring, I do suggest more than just voltage and current in or out. This will not give you accurate gauge of actual battery capacity remaining. If your going to monitor a battery why would you not want to know how much capacity you actually have. Voltage is not a reliable way to measure this at all while a battery is in use so my suggestion is to use something that is a tad smarter. You dont need touch screens etc, something like the victron bms700 or a trimetric from bogart is plenty and very useful. I have a trimetric on my camper and wouldnt consider not having it.

thank you for your time! i will look into it.

same goes for everybody else. Thank you for your time! im getting towards the end here and soon ill know enough to be able to put something together on my own.
 

jeffjeeptj

Adventurer
As long as the sprinter aux battery is a factory option, i would assume it has an isolator that disconnects the main battery when ignition is off. It may even be a smart isolator based on voltage of one or both factory batts. I understand the desire to have more batt capacity, but, that factory aux batt has around 100 ah capacity.
To use the van alternator for a charging source, i would recommend tieing the factory aux batt into your system. Try sprinter source to understand how that batt isolation works.
For a batt monitor i am happy with the bogart trimetric (thanks Handy Bob). I would use a dedicated solar controller (mppt) and portable panels. If you want the 200 ah, I would add 1 more battery directly tied to the factory aux batt via 2 200 amp fuses (a fuse at each battery end of the cable) and proper size cables. The wiring needs to be protected, but does not have to be over complicated, and can be easily removed for the return to van use time. If you are going to have the travel mode in future times, make the wiring more permanent, maybe after this first time to validate it works as expected.
To get more fancy, a charger like an iota 45 or 55 amp will enable topping up the aux batts when plugged into shore power.
 
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Bravo30

Well-known member
As long as the sprinter aux battery is a factory option, i would assume it has an isolator that disconnects the main battery when ignition is off. It may even be a smart isolator based on voltage of one or both factory batts. I understand the desire to have more batt capacity, but, that factory aux batt has around 100 ah capacity.
To use the van alternator for a charging source, i would recommend tieing the factory aux batt into your system. Try sprinter source to understand how that batt isolation works.
For a batt monitor i am happy with the bogart trimetric (thanks Handy Bob). I would use a dedicated solar controller (mppt) and portable panels. If you want the 200 ah, I would add 1 more battery directly tied to the factory aux batt via 2 200 amp fuses (a fuse at each battery end of the cable) and proper size cables. The wiring needs to be protected, but does not have to be over complicated, and can be easily removed for the return to van use time. If you are going to have the travel mode in future times, make the wiring more permanent, maybe after this first time to validate it works as expected.
To get more fancy, a charger like an iota 45 or 55 amp will enable topping up the aux batts when plugged into shore power.

you raise a good point with using the auxiliary battery. that battery is about 4 yrs old so i would have to get a new at some point anyway so might as well get 2, one under the hood an then another identical battery for inside the cab run in parallel. so basically 2 batteries in parallel, one in the cab and one under the hood. with this set-up i could have a somewhat STEALTH house battery system that's tucked out of the way. i could put the 2nd battery under the passenger seat. a ctek 250s under the hood next to the auxiliary battery then a fuse box under the passenger seat then mount a few outlets to the passenger seat base. from there i could wire 12v throughout the van if need be along with the option of portable solar in the future.
 

Bravo30

Well-known member
how would all of that communicate? would the alternator attempt to charge the starter battery first then both auxiliary batteries ? at what point would the ctek come into play?
 

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