Simi 60
New Member
- Joined
- Jul 10, 2021
- Messages
- 159
Hi
We are full time cruisers on a boat that is set up to be away from shore power indefinitely.
When we got her the batteries and inverter were dead and on the perhaps false assumption that it was sized correctly, simply replaced with a bit more.
8 batteries replaced 6 and 5000w inverter replaced 3000w.
It seems to have worked well, batteries never get below 80% SOC (20% used) and due to large solar and Genset head start if needed (cloud/winter) have been at 100% by lunchtime every day so says the Victron battery monitor.
Saying that batteries are showing signs of fail after 5 years so I am here to learn more about LFP
Before we go to much further I will give you a rundown on what we have so as to ensure suitability and compatability with an LFP setup.
Main 240v loads come from 3 fridge freezers one 550 litre 2 door, a 120 litre bar fridge and same size freezer all running 24/7.
Occasional use of 240v pressure cooker - once a week for an hour
Very occasional use of 240v microwave - once a month for 10 minutes
2 Lenovo tiny PC running 24/7, screens turned off when not in use.
Daily we manually turn on and off the 240v 180 litre hot water system - we do that either with Genset running or plenty of sun
In the future, I would like to consider a 240v induction cooktop.
Everything else, pumps, lights are 24 or 12v
To power this we currently have.
8 X 220ah AGM @ 12v joined into 24v
Charging is provided by.
9 x 250 watt Jinko solar panels on flat roof running through a Midnite classic 150 mppt
A 7.5 is diesel Genset
And a victron 5000va 120 amp inverter charger
I did plug all that into a sizing calculator and included the hot water system it came back saying I needed about half the battery bank that I currently have, which based on current experience surely ain't right.
Pics of results included
My initial guestimate was we'd be after at least 400ah of LFP, preferably more.
I was considering 8 X 400ah Winston cells but felt that may not be enough
On here reading about the "blue" cells and we could power a planet for similar coin.
Thoughts about sizing?
Am I on the right path?
Worry about cell brand choices latter
We are full time cruisers on a boat that is set up to be away from shore power indefinitely.
When we got her the batteries and inverter were dead and on the perhaps false assumption that it was sized correctly, simply replaced with a bit more.
8 batteries replaced 6 and 5000w inverter replaced 3000w.
It seems to have worked well, batteries never get below 80% SOC (20% used) and due to large solar and Genset head start if needed (cloud/winter) have been at 100% by lunchtime every day so says the Victron battery monitor.
Saying that batteries are showing signs of fail after 5 years so I am here to learn more about LFP
Before we go to much further I will give you a rundown on what we have so as to ensure suitability and compatability with an LFP setup.
Main 240v loads come from 3 fridge freezers one 550 litre 2 door, a 120 litre bar fridge and same size freezer all running 24/7.
Occasional use of 240v pressure cooker - once a week for an hour
Very occasional use of 240v microwave - once a month for 10 minutes
2 Lenovo tiny PC running 24/7, screens turned off when not in use.
Daily we manually turn on and off the 240v 180 litre hot water system - we do that either with Genset running or plenty of sun
In the future, I would like to consider a 240v induction cooktop.
Everything else, pumps, lights are 24 or 12v
To power this we currently have.
8 X 220ah AGM @ 12v joined into 24v
Charging is provided by.
9 x 250 watt Jinko solar panels on flat roof running through a Midnite classic 150 mppt
A 7.5 is diesel Genset
And a victron 5000va 120 amp inverter charger
I did plug all that into a sizing calculator and included the hot water system it came back saying I needed about half the battery bank that I currently have, which based on current experience surely ain't right.
Pics of results included
My initial guestimate was we'd be after at least 400ah of LFP, preferably more.
I was considering 8 X 400ah Winston cells but felt that may not be enough
On here reading about the "blue" cells and we could power a planet for similar coin.
Thoughts about sizing?
Am I on the right path?
Worry about cell brand choices latter