Is this math right?

[NotToFast]

I am building up my new rig and installed a 300ah/12volt LiFePo4 battery first. While waiting delivery of the mounting hardware I went on a camping trip and by mistake left a 12volt light on in the camper. When I came back the Victron shunt said the battery was at 4%. (Did I do it any harm?) I plugged into my house to recharge and according to the shunt the battery was taking in 50amps. I'm plugged into a 15amp plug, so I assume 50amps @12volts is only drawing 5amps on the 120volts circuit. Is that right? The camper I used to go camping is also set up with a LifePo4 100a/h battery. Over the course of the 2 weeks I run that down to 40%. When I plugged that in it would only take 10amps indicated on the shunt. The bigger unit is using a WFCO lithium converters, the smaller is using a Progressive Dynamics Lithium converter. Is it a battery size issue or a converter issue. Maybe my smaller camper's converter really isn't Lithium as much as it could be. It does charge to 14.6. Any ideas?

 

[FilterGuy]

(Did I do it any harm?)

Not likely

so I assume 50amps @12volts is only drawing 5amps on the 120volts circuit. Is that right?

Yes

The camper I used to go camping is also set up with a LifePo4 100a/h battery. Over the course of the 2 weeks I run that down to 40%. When I plugged that in it would only take 10amps indicated on the shunt. The bigger unit is using a WFCO lithium converters, the smaller is using a Progressive Dynamics Lithium converter. Is it a battery size issue or a converter issue. Maybe my smaller camper's converter really isn't Lithium as much as it could be. It does charge to 14.6. Any ideas?

At 14.6V and 40%SOC, LiFePo4 cells will take whatever current you throw at them...even if it is harming them. I doubt the cells were limiting the current.

The BMS will shut down the charge if the current gets too high (it prevents damage to the cells due to over-current. It sounds like the charge current is constant so it does not sound like the BMS was cutting off the charge.

The charger is probably the component that is limiting the charge current to 10A.