Hi all, new here and I will start by saying that batteries and associated calculations are not my forte, and so I’m here to seek advice from the much more knowledgable people here.
Essentially, we have a fridge that works with mains (UK) power via a generator during the day between 7am -7pm via a generator. When that generator powers down, the fridge is connected to a charger/inverter system with the following components to provide power whilst the generator is powered down:
1 x Victron MultiPlus Compact 24/1600/40-16 230V VE.Bus
2 x Rolls 12V S12-128AGM Deep Cycle Battery
The fridge the system powers states an Energy Consumption (kWh/24h) 1.04
We want to replace the AGM batteries for Lithium, and are looking at these:
Can we simply swap the current AGM batteries out for the new lithium ones? Will they work with the existing Victron MultiPlus Compact 24/1600/40-16 230V VE.Bus inverter/charger and/or does anything need to be done to it to make this work?
Would these be a suitable solution and how long would 2 of these batteries be able to power the fridge for?
Apologies for the long post but I wanted to provide as much information as possible.
Those 100Ah lithium batteries should be able to power the fridge for about 40 hours:
1.04kWh/day, 90% conversion efficiency = 1155 Wh/day, or 48W average power.
This is ~2A average draw from the battery, 80Ah @ 2A should give you 40 hours.
Settings: The voltage settings for the multiplus will need to be adjusted to suit the new batteries - this will require a Mk3/usb device, and Victron connect or configure software.
The fridge is actually a pharmacy fridge which holds a quantity of medication which must be held within a relatively small temperature range or it has to be destroyed which is very, very costly.
The existing AGM batteries are a few years old and are used every day. As far as I understand the degredation on these type of batteries means that their lifespan is much less than lithium ones. As such, I think that for the peace of mind and reliability of the system is worth the investment here.
Your opinion and advice is appreciated, so thank you. Again, I am by no means very knowledgeable on this topic.
If the current system has been for around 4 years, do you know what the duration the batteries would/should be able to power this fridge for now? Just as an approximation of course.
LiFePo4 can’t be charged or can only be charged very slowly below 0-5 degrees C. You can discharge below that temperature. Maybe something to consider for your setup. Heating the batteries keeping them above a certain temp will help of course.