I think we're all basically on the same page here - I think it's a new and interesting topic though so I just wanted to add a thought or two in the interest of learning, since I've seen a few people on the forum interested in trying out new battery tech. Seems some of you guys have first hand experience with lithium in vehicles - mine comes from other applications, mainly consumer electronics.
One reason I've seen people typically offer for wanting to try lithium batteries is that they're tired of killing lead acid batteries with deep discharges. One thing about battery management systems is that they're supposed to protect the cells against overcharging and over-discharging, and the ones I've worked with usually do a pretty good job of that. Some BMS however, will blow a fuse (either a physical fuse or a software fuse) if they don't like the state of charge of one or more cells, especially if a cell voltage drops too low. This often leads to a battery that is essentially dead. My point is just that while lithium-anything batteries have a great power density, they aren't necessarily a magical solution to, say, leaving your headlights on.
I'm curious if any of you guys that have used lithium in automotive applications have dealt with BMS issues.
The problem with lead-acid today is they simply don't last as long as ones from 20 years ago did regardless of how you treat them. I don't know if battery mfgrs cheapened them to prop up sales of their costlier AGM units (which still don't last as long as FLAs did 20+ years ago), or if it's from more-widespread lead recycling (meaning more impurities in the finished product causing faster degradation within the battery)... Or maybe both of these working together (mfgrs taking advantage of recycling regulations to boost profits). I don't have concrete data to back these theories... But it sucks for us consumers nowadays.
With LiFePO4 falling inline with more people's budgets, I cannot blame people for wanting to try it (and is why I've been starting to research it more myself). Also the weight savings.
I would suggest anyone wanting to try lithium buy finished batteries that are manufactured with the BMSs already built in (and also don't buy the very cheapest ones you can find... Renogy is a brand I'd feel confident in buying, but I'm sure there are others priced between Renogy and the cheapest ones that are also good).
P.S. I think I give the impression sometimes that I'm a grump and a technophobe. I'm really not, I work with tech like this every day and I enjoy it. I guess I just prefer simple solutions to simple problems whenever possible.
I think the longer you work in tech, the "simpler the better" mindset becomes a mantra. I've been told my methods are extremely complicated, so I'm trying to follow this mindset now, and untether some brain power.
Same same... I wish manufacturers of all sorts of consumer goods would adopt such thinking.
I could go on & on about the physical functions of so many things we own being controlled through touchscreens or touch buttons that operate through CPUs to control relays / motors / solenoids / etc. where simple mechanical control switches, dials, levers, etc. that performed the exact same functions before worked perfectly fine, were more reliable, and provided fewer user annoyances...
(even changing the direction of the air (A/C) vents on some new cars has to be done through the car's touchscreen menu!)
It's crazy to think how so much of the very basic stuff we use nowadays could have been designed by
Rube Goldberg.
Also you know your shit when it comes to batteries, you work in the field or just tinker and like to build things that could kill you if you are stupid. I'm the latter half of that statement but I do work in the electrical and controls field so goes hand in hand
Yeah, the latter here too. I've messed with electrical / electronics since I was about 7... When something piques my interest, I usually want to learn all I can about it.
Glad you weren't hurt... Lithium batteries do command a certain level of respect, they can go pretty haywire if short-circuited and no BMS (or a malfunctioning one) is present.
