Getting Started

[thebarefootbadger]

I'm just starting to gather info on the electrics. I'd like to be able to charge 2 lithium 30A batteries with either the car battery, shore power or solar (1 120W panel). This is a small system for the front of the van to run or recharge a bunch of small appliances, maybe up to 65W - fan laptop lantern hand warmer bluetooth speaker mouse phone etc.. What I'm envisioning is the batteries sitting there in a hand-built console, connected to a charge controller that allows me to plug in one of the three power sources - or possibly all at once? I'd have an on-off switch for the car battery to ensure it wasn't draining while I was parked. 1. Do you think this thing will do the trick - I'm kind of confused about the sort of controller and the amperage needed. 2. Any suggestions on a site or thread for more specific instructions and suggestions?

https://www.amazon.com/SOLPERK-Controller-Waterproof-Intelligent-Regulator/dp/B0946MWYPK/ref=sr_1_4?crid=3KXP3US90HWE7&dib=eyJ2IjoiMSJ9.ntnVYmuys6mH1VMI-6DvCv_uxLRPzxPTbWXxsK5o4c4ErEU01XrNlURScOhD84MONuMx8oSfmZFSHbFpjMHUHBd13twKAKt38rrtOSrXN3qbuH_-0av8Zg33Ydtu-lFV2y8cju7-1_GSzLSUvM5v6mRPQa-SSQsLM-maIyoGvS0R44SZMOPLeVBqPaM4HQzByol_VzE_DiExLt1IXRcj3ZodPKesmCU3-hcvt1nPr3Y.oiQ_EUEygmgvAYAq2GrGBziRxlbaT069PdyjyWJAqpU&dib_tag=se&keywords=battery+controller+with+SAE+ports&qid=1708882320&sprefix=battery+controller+with+sae+port,aps,126&sr=8-4&th=1

 

[eDJ_]

Bob Wells produced this half hour youtube video explaining how to use a "continuous duty solenoid" to charge the house battery when the engine is running. (and the starter battery also)
When the engine is not running the house battery is disconnected such that even if you
discharge the house battery, the starter battery would be isolated and have a full charge to start the engine with. If the house battery is near being discharged to a safe limit and it is a rainy day, you would only need start the engine and recharge the house battery while the engine run. If it is sunny your solar panels could be used to recharge the house battery since the house battery is isolated when the engine isn't running. (as the solenoid breaks the connection when the engine isn't running)

I'm doubt this Solperk Solar Charge Controller will allow you to run shore power thru it to charge the house battery. That would likely require a battery charger. One of those could be a nice backup in the event of a multiple day overcast or rain event.

Charging your Battery while you drive

 

[maki2]

My friends have all been installing DC to DC chargers rather than the old solenoid setups. I do not have direct experience of it as my vehicle has a very small alternator so I do not want to need to replace it. I just stick with charging with a solar panel.