Hi, we are just in the process of committing to buy one of these Lithium Power LIFEPO4
battery packs, does anyone have any direct experience with this business (based in
Melbourne) or their product range that they would like to share or the EV Works BCU mentioned below? (feel free to send a PM also)
Lithium Power 200AH pack
FYI, we have a small power requirement of about 50AH per day and we do not use/need a 240v inverter. We probably do not need 200AH LFP but it’s what fits in our tight space and does give us good capacity for the future and flexibility for long trips so we are happy to invest up front. We are not interested in a debate on LIFEPO4 batteries just if the approach we are looking at is reasonable from peoples actual LIFEPO4 experience and learnings.
The product makes use of the EV Power BCU (BCU-EVPPAK-4C) and I assume will be wired like this.
Wiring Diagram (my
battery will have 8 x CALB 100AH cells not 12 as shown in this diagram). The BCU manual is here:
BCU user guide
As purchased the product comes configured with a high voltage cut-off (HVC) 3.65v and a low voltage cut-off of 2.5v (LVC), with a goal to achieve a SOC Usage Window 10% ~ 90%. Apparently, I could modify these if I wanted to by modifying the BCU directly but I think at this stage I will leave it as is. The HVC level seems ok to me but the LVC seems a bit lower than I would like (see below using BMV). Do these thresholds seem like a reasonable approach to go with?
We also need much better
battery monitoring than we have in place currently in our slide-on camper. For monitoring we are thinking of going with the following products, Victron BMV700 with Bluetooth dongle (must have wireless information as the BMV
monitor display will not be easily seen unless the slide-on is open, can get at if Bluetooth not working for some reason). I was thinking of getting the new Victron BMV712 Smart (BMV702 with Bluetooth built in) but I think I will also be buying the Victron BlueSolar MPPT 75/15 and I think I can use the same Bluetooth Dongle on both units (use on MPPT to setup and tweak as required but leave on the BMV700 99% of the time).
The other thing I think can be achieved with the BMV700 is to use it to trip the BCU latching relay at a slightly higher LVC threshold of say 2.9v thus discharging the
battery pack a little less to hopefully make them last a bit longer (second line of defense). Do this approach with the Victron Energy gear seem like a reasonable approach to go with or are there other products that we should consider that would help us achieve a similar outcome that might be better/cheaper/smarter for whatever reason? (for example an Arduino product that could replace the Victron gear or most of it)
Are there other things that we should be considering for this setup that might stop us learning the hard way? (There is an isolator switch on the pack we are looking at)
When using the BMV700 to trip the BCU latching relay, will we be able to make use the same BCU relay or should we add a second latching relay to the BCU configuration just to keep things more separate?
What BMV alarm monitoring levels would be a good place to start off until we see what works?