Battery Charging

[threepets]

I want to charge my batteries off the grid at night. Can I connect the battery charger to the system at the Buss bars

 

[OffGridInTheCity]

Yes, you can add a charger and feed charging current directly to the battery (at the buss) as long as it's a proper charger for you're battery chemistry. And then power the charger from the grid (or generator). This can occur any time - even in parallel with PV charging current (during the day) if you wish as long as you don't provide more (overall) charging current than the batteries can handle.

 

[Kiwi2000]

Yep absolutely.

 

[threepets]

Thankyou

 

[MisterSandals]

Is the bus bar between the fuse and the battery? The fuse should be closest thing to the battery. Assuming the battery(s) is LiFePO4 because that looks like a class T fuse.

 

[threepets]

Is the bus bar between the fuse and the battery? The fuse should be closest thing to the battery. Assuming the battery(s) is LiFePO4 because that looks like a class T fuse.

Hi, There are 2 - T class fuses, one in the battery box (at the top on the positive 4/0 cable) and one just before the inverter... too much?

 

[threepets]

Hi, There are 2 - T class fuses, one in the battery box (at the top on the positive 4/0 cable) and one just before the inverter... too much? Double click on the pictures and have a look.
View attachment 188544View attachment 188543

 

[threepets]

Is the bus bar between the fuse and the battery? The fuse should be closest thing to the battery. Assuming the battery(s) is LiFePO4 because that looks like a class T fuse.

The batteries are 51.2v LiFePO4

 

[MisterSandals]

Hi, There are 2 - T class fuses, one in the battery box (at the top on the positive 4/0 cable) and one just before the inverter... too much?
View attachment 188544View attachment 188543View attachment 188549

That’s a good question worthy of a new, appropriately named ”server rack fusing” thread. That many in a ra ck is outside my experience level (other levels too!)). Sorry.

 

[mkimid]

The battery should have BREAKER for over current protection, it will be enough to protect your system. but, MUST BE A BI-DIRECTIONAL DC Break, some battery supplier use AC breaker, and it will have huge delay to trip under over-current fault. and then, need a FUSE.

Note, The most DC breaker is the uni-directional, but, the breaker of battery pack should be bi-directional because charge/discharge (bi-direction), when use uni-directional breaker reversely, it can not cool-down arc while breaker is breaking a power under load, can cause a fire. to avoid the directional issue, the pack maker use an AC breaker. there are two issue, the arc from DC is much stronger than AC, breaker may not cool-down it and cause a fire. and, over-current fault is relay on the heating & bi-metal switching, it is delaying the breaking speed.