Hi, I am using an IP22 12/30 to charge a 200amp LFP04 battery. It works well. However I want to leave it connected to shore power to power the fridge. The fridge draws around 4.5amps when cycled on, in a 24 hour period it will average an amp per hour.
Is it safer/better to use ‘power supply’ mode when the boat is unattended or should I simply leave it in ‘charge’ mode to maintain the battery at ‘float’ level and supply intermittent power to the fridge?
I don’t usually leave the battery on charge when I’m not on board for long periods, for short periods - a few hours - I dial it down to 15 amps. Just being cautious.
So to use ‘Power Supply’ or not to use ‘Power Supply’ to keep the beer cold?
Thanks in advance
I have a similar usage case as the OP, but am also wondering about leaving the charger connected to the battery when away from shore power and using the engine / alternator. Is it OK to leave the charger connected to the battery but not the shore power when the engine is running and the alternator is charging the battery?
Thanks.
I am doing that. The IP22 is connected (to the battery) all the time. So is the Victron DCDC charger. When I leave the pen, shore power is disconnected and the DCDC kicks in as soon as I start the motor (albeit for a short while - it’s a sail boat!). The only charging system I disconnect from the battery is the solar regulator (also Victron). That mainly because I haven’t built my confidence in that side (solar) yet. Eventually I expect that I’ll be able to have all three charging simultaneously (AC - DCDC - Solar) as they should all resolve correctly to the sensed battery level. Wishful thinking? does anyone know?
Thanks @BunyipC30 . I had guessed there should be no problem as the charger will not be trying to charge and the alternator will not put out more than 14 volts, but really good to get confirmation. I have a narrowboat with separate alternator for the leisure batteries. There has been a non Victron (Sealey 12A) charger connected for some time with no apparent issues, but thought I’d best ask.
On my boat I used to leave all sources connected all the time as I do now in the caravan. The only thing I do is if it’s continuously sunny and the LifePo4 batteries are full I switch off the MPPT controller in settings, there is very little draw on the boat.
On a previous boat the charger was wired on the boat side of the isolator, for winters on shore power the charger was set to PSU mode and the battery isolator switched off.
Spent 10 years doing that.
Why do you do that?
The MPPT will throttle production (down to zero, if there is no other consumption) when the batteries stop absorbing power because they’re full… and start to deliver again whenever you activate some load.
LifePo4 batteries are better not stored at 100% unlike LA.
There is nothing draining the battery when not in use so no reason to keep them at 100%.
Presently they are at 62%, there is not enough sun to heat the battery and charge it and that’s fine. I have no landline at present.
If I am there using the battery then I leave solar on.
