Just curious - why Lithiums are so heavy?

Almot wrote:
Electric car battery works in different conditions, it has (I think) liquid cooling system that drop-in batts don't.

I'm not sure it really goes down to 5%, what you see on display is not necessarily it, they might show you only % of a "usable charge", but I don't have electric car. Common recommendation for drop-in 12V Li, and 24-36-48 batts of scooters, ebikes etc is running it in 20%-90% SOC.

Are the RV lithium ion batts ok with standard RV converters?

It needs slightly higher bulk voltage, and Float voltage is zero - charging must stop when full. But let's not deviate.

So... Anybody saw 20 lbs Gr31? ;)

I think I remember reading that. When my car turtles (is completely dead) its not actually dead. The BMS controls that I believe. I have never turtled either car so don't actually know what happens.

Almot wrote:
I'm curious, is there any drop-in Gr31 Lithium, 12V, with BMS, that weighs less than 25 lbs?

Probably not one you'd be willing to pay a grand for.

Can't say I've heard too much complaining about their weight.

Charger voltage depends on the number of series cells and the cell chemistry
The avg new 14+v converter is to high for a 3* 3.7v setup
The liFePos are 3.2v per cell and use four cells in series
4*3.2v

An inexpensive 100 ampHr 12v LiFe made from 18 cells of Chevy volt battery

Is $400
A car box drop in is around $900

Electric car battery works in different conditions, it has (I think) liquid cooling system that drop-in batts don't.

I'm not sure it really goes down to 5%, what you see on display is not necessarily it, they might show you only % of a "usable charge", but I don't have electric car. Common recommendation for drop-in 12V Li, and 24-36-48 batts of scooters, ebikes etc is running it in 20%-90% SOC.

Are the RV lithium ion batts ok with standard RV converters?

It needs slightly higher bulk voltage, and Float voltage is zero - charging must stop when full. But let's not deviate.

So... Anybody saw 20 lbs Gr31? ;)

Almot wrote:
100 AH, flooded, 66-69 lbs.
100 AH, Li, 29-31 lbs.

Brain-dead sellers jumping on a new bandwagon, "One-fifth the weight of a traditional battery", yahooo....

More usable capacity, yes, but not 2 or 3 times more. 70-75% of Li vs 50% of flooded, this is 1.4-1.5 times more capacity.

I'm curious, is there any drop-in Gr31 Lithium, 12V, with BMS, that weighs less than 25 lbs?

Both our cars are Electric.

I don’t know if I would do it all the time but we run our cars down to 5 to 10 percent once in awhile when we make a certain trip and don’t want to stop at a DC fast charge for twenty minutes. The cars don’t seem to care. Probably only a few times a year but that would probably be the same in the RV world.

I haven’t looked into it much. Are the RV lithium ion batts ok with standard RV converters? What does a group 31 lithium ion cost nowadays.

Is that a lithium iron battery? I've read 80% capacity at a minimum, more depending on chemistry and management.