help with Amps on battery. (Merry Christmas)

[charlie22824]

Hey, Everyone Merry Christmas. I have another question though.

I have two EG4-LL 12v 400ah Batteries that will be in parallel so I can have a capacity of 800ah at 12v. Well this is what I'm trying to figure out.

Im thinking that the Charging Current and Discharging current is 200amps and having them in Parrallel will increase my max Charge and Discharge to 400Amps

does this mean I have 800amps? (which doesn't seem possible the wire needed for that would be insane.) Im trying to buy a Victron Smart Shunt 500a but, I also seen a Victron 1000a smart shunt. Thanks for the help!

 

[sunshine_eggo]

Hey, Everyone Merry Christmas. I have another question though.

I have two EG4-LL 12v 400ah Batteries that will be in parallel so I can have a capacity of 800ah at 12v. Well this is what I'm trying to figure out.

Im thinking that the Charging Current and Discharging current is 200amps and having them in Parrallel will increase my max Charge and Discharge to 400Amps

Correct.

does this mean I have 800amps? (which doesn't seem possible the wire needed for that would be insane.)

No. You have a 800Ah battery capable of charging/discharging at 400A.

Im trying to buy a Victron Smart Shunt 500a but, I also seen a Victron 1000a smart shunt. Thanks for the help!

500A smartshunt is fine.

 

[FilterGuy]

I have two EG4-LL 12v 400ah Batteries that will be in parallel so I can have a capacity of 800ah at 12v.

Correct. 800Ah for two 400AH batteries in parallel.

Im thinking that the Charging Current and Discharging current is 200amps and having them in Parrallel will increase my max Charge and Discharge to 400Amps

Correct.

does this mean I have 800amps?

NO. It means you can have up to 400A going in or 400A coming out. However, 400A is crazy high and I would avoid building system that used this much current on continuous basses.


What you have not shared is what you plan on hooking up to this unit. The reason I point this out is that the load and charge devices will define what you need to wire for. If you largest total charge is only 100A and the largest total discharge is 200A, you would design the system around 200A, not 400a.

 

[charlie22824]

Correct. 800Ah for two 400AH batteries in parallel.

Correct.

NO. It means you can have up to 400A going in or 400A coming out. However, 400A is crazy high and I would avoid building system that used this much current on continuous basses.


What you have not shared is what you plan on hooking up to this unit. The reason I point this out is that the load and charge devices will define what you need to wire for. If you largest total charge is only 100A and the largest total discharge is 200A, you would design the system around 200A, not 400a.

I think my largest load would be around 100A. I was thinking that 400a would be a lot of current the wire for that would probably be insane too. I think everything in my van would pull max 110amp at one time. would it be better to wire batteries in series? I haven't bought anything yet for it besides two 12v renogy 200watt panels and 2 12v 400ah batteries

 

[charlie22824]

Correct.



No. You have a 800Ah battery capable of charging/discharging at 400A.



500A smartshunt is fine.

thank you!

 

[charlie22824]

Correct. 800Ah for two 400AH batteries in parallel.

Correct.

NO. It means you can have up to 400A going in or 400A coming out. However, 400A is crazy high and I would avoid building system that used this much current on continuous basses.


What you have not shared is what you plan on hooking up to this unit. The reason I point this out is that the load and charge devices will define what you need to wire for. If you largest total charge is only 100A and the largest total discharge is 200A, you would design the system around 200A, not 400a.

it would be in a sprinter van. I think the ac pulls 60amps max. but the ac is 24v but, the company who put it in for me wired it in a 12v wiring.

 

[FilterGuy]

I haven't bought anything yet for it besides two 12v renogy 200watt panels and 2 12v 400ah batteries

Don't buy anything else till you have a complete design.

Will you have an inverter?

 

[charlie22824]

Don't buy anything else till you have a complete design.

Will you have an inverter?

yes! A victron inverter charger

 

[charlie22824]

.

 

[charlie22824]

Im Assuming If I bought 2/0 Battery wire that is Capable of handling 200amps of power then I'd be fine(Correct me if needed). I know I defiantly wouldn't pull more than 150amps max ever if I had everything single item in the sprinter van pulling max power on the DC and AC side at the same time.

 

[RCinFLA]

Battery connections for more than 150 amps are very difficult. Slight differences in terminal connection resistance will greatly affect current sharing between batteries at high currents.

The EG4 12v 400AH are likely four paralleled 100 AH cells, so with two of the battery packs you actually have four in parallel with 4 groups in series for 12v, through BMS, interconnects, then two of these batteries in parallel.

The probability of equal current sharing between the eight parallel cells are just a little better than zero so don't count on drawing that much overall current.

If you plan on a 12v inverter greater than 1500-2000 watts you will likely have current sharing issues.

At least get a clamp-on DC amp meter to periodically check the sharing between batteries.

 

[charlie22824]

perfect thank you! yes I was only going to get a Victron multi plus 12/2000 | 12V Input | 2000VA output 120v | 80a charger

​

 

[charlie22824]

Battery connections for more than 150 amps are very difficult. Slight differences in terminal connection resistance will greatly affect current sharing between batteries at high currents.

The EG4 12v 400AH are likely four paralleled 100 AH cells, so with two of the battery packs you actually have four in parallel with 4 groups in series for 12v, through BMS, interconnects, then two of these batteries in parallel.

The probability of equal current sharing between the eight parallel cells are just a little better than zero so don't count on drawing that much overall current.

If you plan on a 12v inverter greater than 1500-2000 watts you will likely have current sharing issues.

At least get a clamp-on DC amp meter to periodically check the sharing between batteries.

ok ill look into getting a clamp- on DC amp meter thank you so much!

 

[Rocketman]

Just remember the Victron Multiplus 2000 will only deliver 1600w. (Too many people think that is a 2000w inverter).

Also Victron recommends 70mm2 wire which is about 2/0 wire - (2/0 wire is 67mm2). And a 300a fuse.

You want your system to be able to handle the inverter at full load - even if you don’t think you will get there.

Good Luck

 

[charlie22824]

Just remember the Victron Multiplus 2000 will only deliver 1600w. (Too many people think that is a 2000w inverter).

Also Victron recommends 70mm2 wire which is about 2/0 wire - (2/0 wire is 67mm2). And a 300a fuse.

You want your system to be able to handle the inverter at full load - even if you don’t think you will get there.

Good Luck

thank you yes! I've figured in everything the 1600 Watt will handle everything I need. I've spent the extra money on low amp/watt appliances that I need also using propane for the cooktop because I like cooking with propane more. the 3000 watt would be nice but it would be over kill.