Offgrid Cabineer, N.E. Ontario, Canada
I don't remember if you said you already bought your battery cells or not or still in the advanced planning stage. sorry been a really long day.My application is a sailboat. For me it's essential to be able to communicate with my Victron equipment on board. If you go the route of multiple parallel packs with each a separate BMS, communication is an issue. I talked to REC BMS on this topic, and they said you need a BMS for each pack + on top of that another BMS that will act as master.
For my application, this is way I eventually choose Batrium with the decentralised approach. This way there is just 1 BMS talking on the Canbus to my chargers.
Steve, you're absolutely right. For my use case (again sailboat) I'm limited in space (existing battery box) and have only 2 real options:
The cost difference is huge and I can even be more conservative on the range in which I'll use the EVE cells. On top of that I have a battery system that communicates with my chargers (unlike the Battleborn dropins) and doesn't use mosfets to cut power (like all the popular chinese BMS systems), but a decent industrial contactor rated to 20kA. All the additional cell monitoring is just an added bonus.
- Custom build a battery (24 EVE 280Ah cells in 8s3p + Batrium monitoring). Batteries : 2000USD, BMS: 1500USD -> 3500USD for a total of 840Ah. Because the cells are not balanced, I can only use them between 20-90% or 590Ah usable energy. The total cost is 5,9 USD/Ah ( 3500USD/590Ah)
- Buy Battleborn batteries, but due to their dimension I can only fit 8. This gives me 400Ah (they are balanced so let's say 100% usage) for a total cost of 7200USD (900USD/piece). Cost is 18 USD/Ah (7200USD/400Ah).
If you have not bought yet. Then you may want to consider spending a bit more for EV Grade cells or even step up to matched & batched from a manufacturer
Some companies like BB, for instance, use cylindrical LFP, they are smaller in AH capacity per cell but they parallel them up. These are more readily available in a higher grade level. the end result does cost more but your ending up with better. Alternately, step up to CALB, now be cautious there... there are different series of CALB, even blue-ees, their ratings & capacity for charge & discharge are different for different purposes, including EV use. Of course prices reflect such. It is a matter of compromises relative to budget capacity and ultimately what you "need". For me, in a boat, at sea, Murphy's Laws kick in, Davy Jones' locker starts sounding, I would NOT want to worry about my batteries ! No Feckin Way Mate ! LOL.
Sorry, but for many years while I was involved with defence, one of my tasks was to consider the situations we could encounter... The prime adage was "Crisis Management begins with Prevention & Planning" the first rules... and I know All about Murphy's Laws and how that blighter comes when "shit is real". as it were.