Hi! First post, sorry if this has come up before.
My canal boat in Amsterdam has a 48V traction battery pack ± 1300 Ah that is in reasonable condition for its age (never completely run down, timely demi water refills). I want to run about 3KW of electrical heating off the battery pack, in addition to propulsion, for about 5 hours, multiple times a week. While my 230V onboard AC power net will be able to manage this (barely), it will put a greater strain on the battery. The electric system is Victron based, with a Quattro 48V/10000, transformer, VRM etc.
I’m looking to supplement the battery capacity by installing an additional LFP battery, and I need help weighing the pros and cons of the following options:
Mobile power station battery with integrated AC power outlet
…and run a heater directly from it.
pros
- no installation required
- semi portable, can be used for other stuff outside of winter season
cons
- expensive, as I’ll likely need two to get the required output wattage, and also 2 extension batteries
- it’s a lot of gear that I can’t store out of sight
- elevated risk of theft
install LFP battery with separate charger/inverter, just for heating
And run separate 230V AC lines to electric heaters.
pros
- current electrical system remains as it is
- somewhat cheaper than 2 power stations (haven’t done a price comparison yet)
cons
- no communication or synergy between the two battery systems
- not portable, so the system is stuck doing nothing for 3/4 of the year.
- once the battery is empty, the heating fails, even if the main battery has plenty of power left.
Install LFP battery with some form of DC-DC charging to supply power to the lead acid battery pack
Main battery deals with the additional heat power load, but is fed additional current from the LFP battery. Victron Quattro will charge the LFP battery, which will in turn charge the lead-acid main battery.
pros
- seems like the most elegant solution (to my untrained eye)
- I think I should be able to charge both batteries with the
- outside of heating season, LFP battery works as a range extender
- hopefully life extension for the main battery??? (I don’t know if this is the case)
cons
- I don’t know if this will work
- Victron doesn’t seem to offer a product that can integrate the two systems and regulate the voltage difference.
I’ve been advised against it by an electrical engineer who said it’s a bad idea, but couldn’t articulate why (other than: “I don’t like it. Nobody else is doing it”)
Any insight is greatly appreciated.
context: the boat is a professional indoor aluminium Amsterdam canal boat for ± 25 people. This winter we’re expecting a busy boating season during Amsterdam Light Festival, and heating is becoming an issue: using fuel-based heaters is not an option due to ES-TRIN regulations (It’s a passenger vessel. Also, city center will become a zero emission zone). I’d like to keep the lead acid battery as I actually need the weight of it to avoid paying money for ballast.