16 cell 74ah battery setup help

[beowulf]

Hey all. Just ordered some of these LEV60F batteries from JAG35.. $550 shipped to my door for 16 cells. From the info Jehu provides, they seem like really good cells. Brand new, 74ah.. should be about 3.7Kwh bank. From what I can calculate, with his 16 cell PCB bus/bar for $120, it still works out to a better per Kwh price than anything else I've found. Granted, it's only 74ah batteries.. but hoping being Japanese they are good quality.

At any rate.. I bought them given the lower price so I could run a 48v bank that I could charge in off peak hours, and then hopefully use it during peak hours to power my River Pro 2 Ecoflow battery, which I have my computer/monitor plugged in to. Based on my peak energy rate, I pay about $80 a month to use my computer all day every day, as I WFH. It runs about .58kwh peak.. and I am literally peak for 10 hours a day 7 days a week.. what can I say I'm an introvert and sit/stand at computer every day. Well most of the time.

So.. I would need a charger that can charge the battery, a BMS, and I assume a pure sinewave inverter to feed the battery to my river pro 2 to charge it? Can someone elaborate a little on what exactly I'll need to do this right? What BMS is best for this pack (I will have to check Jehu's video again), and is there any BMS that offers some sort of app (or wifi/bluetooth capability and possibly IoT via MQTT maybe? for data) that I can use at any time to monitor batteries? I think there is some sort of need to check all 16 cells from time to time to make sure they are all within .1 or .2 v of one another and if not to balance them? I recall from drone stuff with 3s/4s/6s batteries we have to balacne cells. So does the BMS handle this too? How do you monitor/initiate this?

Thanks.. appreciate help.

 

[Brucey]

To add extra battery capacity to my Delta 2 max I'm using Redodo 12v 100Ah "minis". Just connected to the solar input(s).

Looks like the river 2 pro has a solar input limit of 11-50V 13A and 220W max. So your 48V battery will be too much voltage. However you could use an Orion 48-24 converter instead of losing efficiency by doing a DC->AC->DC conversion, if 220W input is enough to cover your load for the 10 hours of peak at 58 cents per kWh, assuming you start with a full battery on the r2p.

Victron Energy Orion-Tr 48/24-12A DC-DC Isolated Converter

Part Number: ORI482428110

www.solar-electric.com

 

[beowulf]

Interesting. I assumed 50v input would allow the 48v output of battery.. its less than the 50v max.. is that not ok? Is the 600a output of the 48v 74ah pack too high? I assumed that just meant it could handle 600a discharge rate.. but that it could go much less.. based on the draw of the device it's powering right?

So the River 2 pro also has the AC input (e.g. ac plug to main power).. would 48v with an inverter to 110 be more efficient/better than a 48v to 24v path?

 

[Brucey]

Interesting. I assumed 50v input would allow the 48v output of battery.. its less than the 50v max.. is that not ok? Is the 600a output of the 48v 74ah pack too high? I assumed that just meant it could handle 600a discharge rate.. but that it could go much less.. based on the draw of the device it's powering right?

So the River 2 pro also has the AC input (e.g. ac plug to main power).. would 48v with an inverter to 110 be more efficient/better than a 48v to 24v path?

48V nominal is usually more like 54V in reality. The amp output isn't a factor, as you said the r2p will pull what it needs.

You will lose more energy running 48V-> inverter to 120 into the r2p, however it will charge much faster than it can via its solar input. Need to decide if charging at 220W will get you through your peak period. Or if you need to use inverter and maybe top up a couple times a day. The Delta 2 is a little friendlier for charging via 48V batteries as it supports 11-60V at 15 A and 500W (Delta 2 max having two ports and 1000W input).

 

[beowulf]

So I want to charge at about 220.. same as solar panel would charge it at. So a 16s 74ah 48v battery bank.. to charge at 220w around 48v.. need some sort of inverter I guess? I'd like to stick to Victron but not pay crazy prices right now as this is about $550 in batt shipped, trying to keep this somewhat low cost to pay it off in 2 or so years in savings.

Also.. the video/etc lacked any info on what BMS to buy for this setup. Any suggestions for a BMS that handles charge/discharge + trickle to avoid overcharging, and balance charging the cells when they need it?

 

[Brucey]

If 220W charging rate is ok then just use the Orion 48-24V converter, that's the most efficient way to get what you need to max out the river 2 pro solar input, keeping it all DC.

 

[beowulf]

Not disagreeing.. as I don't know.. but why? . I want to learn/understand so I can eventually solve these and help others. Is it because it's DC to DC.. and that stepping it down to 24v from 48v is more efficient than going 48v to 110 (or 120) and using the AC plug?

So eventually when I get some panels set up outside, and wire ran to the inside battery (not in my garage for now).. I'd want an MPTT to charge the 48v pack.. which in turn is going 48v to 24v DC to plug in to the solar input on the River 2?

From what I am seeing, the Victron Orion 48-24 puts out 380watts.. about $210 on amazon. Is that the right one?

 

[Brucey]

Not disagreeing.. as I don't know.. but why? . I want to learn/understand so I can eventually solve these and help others. Is it because it's DC to DC.. and that stepping it down to 24v from 48v is more efficient than going 48v to 110 (or 120) and using the AC plug?

So eventually when I get some panels set up outside, and wire ran to the inside battery (not in my garage for now).. I'd want an MPTT to charge the 48v pack.. which in turn is going 48v to 24v DC to plug in to the solar input on the River 2?

From what I am seeing, the Victron Orion 48-24 puts out 380watts.. about $210 on amazon. Is that the right one?

Taking 48V DC, running it thru an inverter to deliver 120V AC, then feeding that into the r2p AC input to then convert back into DC to charge the r2p internal battery is inefficient. Especially when compared to using a 48/24V converter.

If you want to keep costs down there's no need to pay for a Bluetooth in your proposed configuration. I don't see it on Amazon. You want the 48/24 12A, seems to list for $120.

Victron Orion-Tr IP43 DC to DC Converters – Non-Bluetooth

Victron Orion Tr DC to DC Converters Chargers IP43 Non-Bluetooth are high efficiency & can also be used as a battery charger.

invertersrus.com

 

[beowulf]

OK.. thank you for that info. Yah.. makes total sense. One less inversion of AC back to DC is good. I wanted bluetooth mostly so I can eventually monitor ALL my victron gear as I add more over the near future. But I am fine without as well. Is Victron the only way to go.. or are some of these other options I see for much less as good or not worth it. Basically I want 48 to 24, 12a.. no other stats matter?

Something like this one wont work: https://www.amazon.com/Regulator-Converter-Waterproof-Transformer-Automotive/dp/B0BTM6SFRF/ref=sr_1_2_sspa?crid=1SSMMIZIN0JOJ&keywords=48v+to+24v+12a+isolated+charger&qid=1695417666&sprefix=48v+to+24v+12a+isolated+charger,aps,131&sr=8-2-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9hdGY&th=1

Just to be clear.. the 48/24 12a you are talking about says 280watt output.. is that going to be too much for the 220 max input on the River 2 pro?

 

[Brucey]

Yeah that should work. As long as the input to the r2p is 50V or less it will be ok. It will only draw up to 220W.

Just an FYI you will need to use an xt60i connector with the signal pin connected to the negative lead if you want the r2p to pull more than 8A. Otherwise it defaults to 8A max to avoid blowing a vehicles accessory socket fuse. Something like the link below. You could add some mc4 connectors to the buck convertor output to connect it up.

https://www.amazon.com/gp/aw/d/B0C993CKT7

The official ecoflow solar charge cable is also available from the ecoflow website but a little more money.