280Ah Lithium LiFePO4 battery system upgrade for 1300e

[Mika Harju]

I replaced the AGM batteries with Chinese LiFePO4 batteries, necessary control electronics and updated all electric supply system on 230VAC and 12VDC side.

My plan was to engineer and build a system without any leading brands (Mastervolt, Victron etc.) to avoid the complicated and expensive solution they provide including a unavoidable data network they use. When you choose this kind of system you have to keep it the rest of your life and it is difficult or even impossible to add any other equipment than the brand offers. In case of problems you need to call a specialist to come and fix everything onboard. Takes time and a lot of money needed. I bought several pieces of each cheap Chinese electronics to keep those onboard as spares, all engineered to be easy to replace.

System consists of:
1- Four LFP batteries connected in series
2- BMS1 electronics to control battery overcharging including solar energy and ac charger etc. BMS1 takes care of battery cell balancing too.
3- BMS2 electronics to control battery undervoltage protection. A stand alone Victron product.
4- BMS3 electronics to control Volvo diesel engine alternator to prevent overvoltage charging.
5- BMS4 electronics to monitor battery status including voltage, current, charge status, energy consumption etc.
6- Inverter Victron, stand alone product.

Technical data:
1- Battery 12.8VDC @ 280Ah, about 3.5kWh, LiFePO4 chemistry, safest one nowdays
2- BMS1 over voltage protection 14.65V, fixed value
3- BMS2 under voltage protection 11V, programmable by simple switches or Bluetooth.
4- BMS3 diesel engine charge cotroller, over voltage protection 13.6V, programmable by simple switches
4- Ac charger 14.65V, 2-50A adjustable
5- Inverter 230Vac output, max 500W
6- Solar power 287W nominal power, MPPT charger, 3 panels parallel connection
7- Volvo engine ac alternator, 13.6V @ 60A
8- Automated contactor to switch between shore power and inverter power.
9- Battery size is about one third of AGM battery system
10- Battery weight 21kg
11- In an AGM system there is about 50% of the nominal energy usable. In LFP it is possible to use 90% or even more of the nominal capacity.
12- One battery system, same battery to start the engine and for consumption.
13- In case of battery low voltage shutdown it is possible to skip the BMS2 electronics by a switch to start the Volvo engine.
14- Our daily total energy need is about 1kWh and in summer time the solar power system keeps batteries fully charged
15- Battery cycle life +3500 charging cycles between SOC 10-90%. Espected working life +10 years.

Prices, total cost less than 1 300€:
1- LFP batteries 4 pieces 400€
2- BMS1, BMS3 and BMS4 total 50€
3- BMS2 100€
4- Inverter 200€
5- AC charger 100€
6- Wiring, connectors, electromechanics, special tools etc. total 400€

[Tuca]

Hi Mika,

I want to install this winter chinesse EVA LiFePo4 batteries in my DF1000. Also the 280Ah model.

Was thinking to install a Daly Chinesse BMS.

I have heard that is necessary to limit the current from alternator to avoid it to overhead, due that LiFePo4 batteries have less internal resistance.

What devices have you use for BMS1, BMS2, BMS3 and BMS4?

Do you have links to the chinesse electronics that you have use? I'm good with electronics and have not problem aking any king of electrical instalation.

The BMS3 electronics that control the volvo diesel alternator is the deviced that I am specially interested.

Thanks in advanced