Hey there! I'm working on a project with my VW Caddy van, which I mainly use for work. Sometimes I need more power for tools like chargers and a chop saw (1300-1800W), and I'm even considering camping in the future. I'm thinking about getting a Renogy 3000W inverter to connect directly to the car battery, using it while driving to keep things powered. It seems like an affordable temporary fix. Alternatively, I'm also pondering whether to add a 100Ah LiFePO4 battery to act as a buffer. I prefer the 3000W inverter because I plan to upgrade to a bigger van down the line, but my budget is limited. Is this plan sensible? What do you recommend for a cost-effective setup? Thanks!
3 Answers
Keep in mind, a 3000-watt inverter at 12 volts would pull around 250 amps! Your alternator won't be able to handle that load without an upgrade, and your starter battery might not last long either. If you want to stick with that wattage, going for four or more batteries in series to hit 48V is the way to go. This approach reduces the current draw significantly. It's cheaper to invest in batteries and a decent inverter than a high-priced alternator, but also think about just getting a generator instead; it could save you a lot of trouble in the long run.
You're right to be worried about the startup current demands, especially with tools like a chop saw. Inverter brands like Victron can handle the strain well. A 100Ah LiFePO4 battery could give you enough power for short bursts (like making coffee or cutting) if you're careful about the wiring. Make sure to install a proper DC-DC booster to regulate charging when the car is running, and consider upgrading your alternator to handle the additional load if you can. It's all about finding the right balance!
You're definitely going to need some heavy-duty wiring for that 3000W inverter hooked up to just a single car battery. I suggest using four batteries in a series for a 48V system, which will keep your starter battery safe by not draining it. The shorter your wire runs, the less you'll spend and it’ll be simpler to set up. You can also charge this battery setup via the car's electrical system while driving, which makes it a smart option for future solar integration too! Stick with the 12V LiFePO4 if you're looking for something more compact, just make sure it's right next to the inverter and use thick wires for connecting them!
Thanks for the advice! I hadn't considered a DC-DC booster, but that makes sense. I'll look into upgrading the alternator too!