Which way to go to power 2000W Inverter, pro & cons including cost

[HKZBob]

Dear all,

thank you for your advise in advance. US goes green again. Looks like solar gets a push.

I using a 2000W Inverter in my RV who is used temporarly and most of the time is off by remote switch.

I am struggleing want to start a DIY project to power my RV with 300W Solar on top.
I have decided to go with a Lifepo4 12V 200Ah. I think will go with Higree cells (Soonbuy)

My choice
Now my first thought is to connect inverter direct to the Lifepo4 pack with a

• 200A Fuseblock.
• than to connect an 5A active balancer

But I also like the Bluetooth monitoring. ( So still ad an 30A Smart BMS use the bluetooth, only for that purpose)
Thank I have an active and passive balancer. (The active I can not use anymore. Smart BMS needs the cell voltage)

Roadblock!!!!

If I go this path low voltage protection will be monitored by my RV. It starts beeeeeping when BAT is low.
Over Voltage protection is monitored by my Electronic Block of the camper.

Do I need als the monitoring ???

1. Or shall I buy a 200A Smart BMS and Basta. If it breaks buy an new one!!!!!
2. Or shall I do with a small BMS and place a huge contacter behind it.
   • but from time to time the BMS is off
   • Even when my inverter is off the "Inverter Caps" will be charges and this causes heavy arcing in the contactor and kill it over time.

I would like to understand which is your experience with high loads in your RV.
Which way did you took and and how about the durability.

My favourite is below but how can I do cell monitoring on my smart phone.

Do you know a module which makes a cell monitoring without balancer function for my mobile?

• connect inverter direct to the Lifepo4 pack with a
• 200A Fuseblock.
• than to connect an 5A active balancer

Thanks
Bob

 

[Dzl]

my 2c:
Whichever route you choose, the BMS should be able to manage/protect--not just monitor--the system. Particularly if you think you have the need for a 5A balancer (which would imply an unmatched pack).

This means a BMS that can disconnect charging and discharging if cell level parameters are exceeded (high or low voltage etc). How to accomplish this (big FET based BMS, contactors, etc) is up to you, but I wouldn't rely on balancing alone.

 

[Zil]

I use my BMS as the last ditch protection for the 12V 200ah battery of 8 LFP cells. So the inverter has a LVD that switches off higher voltage than the BMS. My system gets a little complicated so I switch off the inverter load before the LVD and that before the BMS. I do not have problem with arcing. --> "Even when my inverter is off the "Inverter Caps" will be charges and this causes heavy arcing in the contactor and kill it over time."

 

[HRTKD]

I think you're making a system that is more complicated than it needs to be. My OverKillSolar BMS does passive balancing and the cells are very closely aligned, within .005v most of the time. I see cell voltages right on my phone.

I have a 4s2P configuration for 560 Ah of capacity. However, I'm using an inverter that is only 1000 watts.