What charger to charge 48v bank and a few questions

[beowulf]

Hi all,

I am building my first 48v bank (16 x 3.2v cells). It's the Jehu Garcia battery kit with his rack mount server case, etc, 100a BMS from china, etc.

I am going to be getting the Victron MultiPlus II 3000 or 5000 (ideally 5000). But that is a couple months out give or take finances. In the meantime, I know EG4 has that $400 battery charger, but I really didn't want to drop 400 on that right now as I want that to go towards the Multiplus II unit.

So, is there an "affordable" charger that I can use to charge up the battery in the meantime?

The BMS is the one from the video he has (https://www.aliexpress.us/item/3256...il_item.4.4446f19cWexxqc&gatewayAdapt=glo2usa). I assume it has the ability to control the charging amount.. e.g. I can tell it to stop charging at 80% capacity? Or maybe I can't. I am hoping the MultiPass II (along with the Cerbo GX that I plan on getting) will allow me to control the amount of charge, the time to charge, etc. But until I have that, I just wanted to be able to charge this up.

I plan on using a 15a AC outlet.. so ideally a charger that wont pull more than about 14a from the wall, and will charge up during off peak hours (midnight till 2pm). I can then use a simple Amazon or TPLink smart plug thingy to set up a simple timer to only turn on at 12am or so (obviously assuming I dont run out of battery before then). Another reason not to go past the 14a or so draw as those are typically 15a plugs.

So as I understand it, the +/- terminals of the battery are 48v, right? The Victron inverter/charger will have AC outputs that are 110v (hence the inverter part) but right at the battery it's 48v input/output at the terminals right? I have a Victron 48v to 24v DC to DC converter because presently I am powering things off of an Eco River 2 Pro battery and it has a max 50v input solar input charger. So the 48v to 24v Dc to Dc is to feed that to charge that up while I use its inverter to power a few things. So I assume I run a 6 gauge +/- wire from the terminals to that 48v/24v input side right?

I will have to figure out about how much time 14a or so charges up the 3.7Kwh battery. Not sure if it will take several hours or charge up faster than that. Ideally I want to prolong the life of the batteries to the 6000+ cycles they are rated for, so would rather charge slower than faster but still charge it enough so that I can use the battery by 2pm when peak kicks in.

I am also unsure of if while charging the Ecoflow river 2 pro during off peak AND the battery itself might be charging, if that will work. Will the AC input to charge the battery go directly to the 48/24 dc/dc since it would attach to the same +/- terminals?

Thank you.

 

[DIYrich]

Look at Will's diy battery build videos. Buy a bench 3.2v battery charger for about $50, i think. You should charge individually to the same voltage, then parallel to balance, before putting in series.

 

[jnrhome]

I use this:

https://www.amazon.com/Adjustable-Converter-Switching-Regulated-4-Digital/dp/B08JPKQD41

They also make a 24a which I also have. I use them both, set to 51.4v and plugged in to the grid to keep my banks from going to low on my off grid system. They have been excellent performers.

 

[Brucey]

Hi all,

I am building my first 48v bank (16 x 3.2v cells). It's the Jehu Garcia battery kit with his rack mount server case, etc, 100a BMS from china, etc.

I am going to be getting the Victron MultiPlus II 3000 or 5000 (ideally 5000). But that is a couple months out give or take finances. In the meantime, I know EG4 has that $400 battery charger, but I really didn't want to drop 400 on that right now as I want that to go towards the Multiplus II unit.

So, is there an "affordable" charger that I can use to charge up the battery in the meantime?

The BMS is the one from the video he has (https://www.aliexpress.us/item/3256...il_item.4.4446f19cWexxqc&gatewayAdapt=glo2usa). I assume it has the ability to control the charging amount.. e.g. I can tell it to stop charging at 80% capacity? Or maybe I can't. I am hoping the MultiPass II (along with the Cerbo GX that I plan on getting) will allow me to control the amount of charge, the time to charge, etc. But until I have that, I just wanted to be able to charge this up.

I plan on using a 15a AC outlet.. so ideally a charger that wont pull more than about 14a from the wall, and will charge up during off peak hours (midnight till 2pm). I can then use a simple Amazon or TPLink smart plug thingy to set up a simple timer to only turn on at 12am or so (obviously assuming I dont run out of battery before then). Another reason not to go past the 14a or so draw as those are typically 15a plugs.

So as I understand it, the +/- terminals of the battery are 48v, right? The Victron inverter/charger will have AC outputs that are 110v (hence the inverter part) but right at the battery it's 48v input/output at the terminals right? I have a Victron 48v to 24v DC to DC converter because presently I am powering things off of an Eco River 2 Pro battery and it has a max 50v input solar input charger. So the 48v to 24v Dc to Dc is to feed that to charge that up while I use its inverter to power a few things. So I assume I run a 6 gauge +/- wire from the terminals to that 48v/24v input side right?

I will have to figure out about how much time 14a or so charges up the 3.7Kwh battery. Not sure if it will take several hours or charge up faster than that. Ideally I want to prolong the life of the batteries to the 6000+ cycles they are rated for, so would rather charge slower than faster but still charge it enough so that I can use the battery by 2pm when peak kicks in.

I am also unsure of if while charging the Ecoflow river 2 pro during off peak AND the battery itself might be charging, if that will work. Will the AC input to charge the battery go directly to the 48/24 dc/dc since it would attach to the same +/- terminals?

Thank you.

Just be aware a 48V nominal battery could be in the 57-58V range when fully charged, so you wouldn't be able to use it directly with the River 2 pro. Delta 2/Max helps in this regard by increasing the mppt range to a max of 60V.

Where do you get the 3.7kWh number from? Should have 5.12kWh capacity in your 16 cell battery assuming 100Ah cells.

 

[beowulf]

Just be aware a 48V nominal battery could be in the 57-58V range when fully charged, so you wouldn't be able to use it directly with the River 2 pro. Delta 2/Max helps in this regard by increasing the mppt range to a max of 60V.

Where do you get the 3.7kWh number from? Should have 5.12kWh capacity in your 16 cell battery assuming 100Ah cells.

Yup. I have the 48v to 24v DC DC Converter from Victron. Also just got my Cerbo GX unit. Just need Signature Solar to handle my return for credit.. been 12 days already and still they haven't given me the damn credit so I can order the 48v Victron Multiplus 3000. Anxious to get it already!

I hope I can just plug that inverter/charger to the battery and the Cerbo GX to the multiplus, and.. the dc to dc from batter to river 2 pro.. or do I need one of those Lynx devices to plug everything in to.

 

[beowulf]

Wait.. so doesnt the 100a 48v BMS that I have for the 16cells balance for me every time I charge it? Otherwise.. how do you know if your cells are not balanced after some time?

 

[beowulf]

I have this power supply.. would this work: https://www.getfpv.com/toolkitrc-p200-mini-200w-10a-power-supply.html