Hello. A few weeks ago, I picked up 3 of the LG Chem modules from that batch of 60 that BH was selling. I'm pretty new to all this so I'm glad to have found other knowledgeable folks who are using these batteries and sharing their designs/experiences. Thanks! It has been very helpful. I will likely be asking a lot of (potentially dumb) questions... so I apologize in advance.
Here is what I am planning:
I am looking to set up residential application as a 48v system using an MPP Solar LV5048 to power a critical load panel that was originally set up as a 10 circuit generator transfer switch.
As I mentioned, the battery bank will be 3 of these 189 ah LG chem modules.
For now, the goal will be to use the LV5048 and batteries as a UPS/peak shaving system. Where I live the off-peak power rate is 1/5 of the on-peak rate, so if I can power my critical loads from battery during on-peak and charge during off-peak, it will be a good start.
Eventually, I will be adding PV. Right now, I only have a few panels totaling 1kW. So Im looking to obtain some more panels before setting up that side of the system.
Anyway, now Im trying to figure out how to wire and manage these batteries. The info w0ss shared on here gave me a lot to think about. I like the breakout board and how clean it makes connecting to a BMS. I will likely be joining you folks in obtaining a few for my setup.
As for a BMS, I want to be able to see all the cell voltages in each module, so I ruled out the Daly units. I was looking into those cheaper bluetooth BMS units but although the price seems favorable, I worry about the quality and dont want to risk my investment in these batteries (and my safety). So I shifted to looking at the Chargery BMS, but I wasnt totally sold on those either. Kept seeing mixed reviews.
I wasnt considering the Batrium system until I came upon this thread. After looking into it more, I like what I see. Its pricier, but seems like you get what you pay for.. a very functional, quality system.
Based on what I learned so far, I think Id need a Watchmon5 and probably 2 additional Multimon units to monitor all 42 cells of the 3 modules. Id consider getting the Shuntmon as well to complete the setup. The cost hurts a little to think about but the capability of that setup is enticing. The one thing Im not clear on is if I would need the Watchmon with the expansion board. Seems like the expansion board is needed if you want to have the ability to remote trip the breaker or control a fan, both of which I would like to do. Is that the case?
One last, dumb question Im looking for some confirmation about what the max current draw could be from my battery bank in order to assist with properly sizing my DC components breakers, wires, fuses. The LV5048 is a 5kW inverter at peak for AC output. I dont expect to be putting anywhere near that demand on the inverter from my normal loads. Based on what Ive seen, the LV5048 taps out pretty quick with very heavy loads/surges. According to the manual, typical amperage is 220A with a recommended minimum battery capacity of 200AH. Recommended wire size from the inverter to the battery is 1/0 awg. Id likely have a wire distance of <5ft for my main DC cables from the inverter to the distribution bar. I was thinking of going with 2/0 wire to be safe and minimize loss. Im not sure what size wire to use from each of the 3 modules to the distribution bar. Wire length would be <3ft. I was thinking 2 AWG and could always double it to be safe. any thoughts on breaker/fuse rating would be helpful as well.
Any input on this is appreciated, thanks!
