Silentpower
Over Rated
No I don't, I rely on the SCC for top cut off, and basic visual meters for bottom. I'm thinking about getting a ssr to connect to the SCC so that can trigger low voltage battery disconnectDo you use a BMS?
No I don't, I rely on the SCC for top cut off, and basic visual meters for bottom. I'm thinking about getting a ssr to connect to the SCC so that can trigger low voltage battery disconnectDo you use a BMS?
Thanks for the detailed information.I did do the capacity test, although it took me quite a while to finally get the video out.
The modules I have range from about 31 Ahrs which is 248 Whrs per module, (8 x 31 equals 248) to 45 Ahr. The 48 volt packs may contain 6 or 7 modules. I know Nissan modules but very little about Big Battery 48 v packs.Thanks for the detailed information.
You mention the batteries were rated by 31.25 Amp Hours, but the Tech Direct Club (aka Big Battery) site shows the batteries as 2.8 kWh which would be considerably more Amp Hours.
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Can you provide any insight?
Are these cells the LG Chem 3.6v 120A Cells?Yikes ?
I have NMC cells 5p14s and have taken them down to below 46v... I'm slightly worried now!
EIG recommended 3.3vpc so I thought I wasn't ragging them excessively, I might have a rethink lol. I charge to 56.5v
Hi Calvin, my cells are flat prismatic NMC EIG cells. They charge to 4.2 maximum and working voltage is nominal 3.6v. Each cell is rated at 20ah and has a sustained rate of 5C and can handle 10C for short bursts. I think they were primarily intended for electric vehicle use. They are arranged in 5p14s, so bunches of 5 in a string of 14. The vendor I bought them from had joining bus bars for each 5p group laser cut. It's difficult for me to take a photo as once the pack was assembled, I wrapped the whole lot with gaffer tape including the top. The connections were put together with duralac anti galvanic paste so I could be confident I wouldn't need to disturb anything for quite a while. Each 5p group has a basic voltage meter so I can, in a basic way, monitor for signs of inbalance.
Thanks for the detailed information.
You mention the batteries were rated by 31.25 Amp Hours, but the Tech Direct Club (aka Big Battery) site shows the batteries as 2.8 kWh which would be considerably more Amp Hours.
The testing I have done with 5 Big Battery Mini Packs showed the kWh capacity ranged from 2.2 kWh on the high end, down to 1.6 kWh on the low end. Strange thing is the Big Battery website shows this same battery to be 2 kWh.
Since Tech Direct Club and Big Battery are the same company, I am curious why the same battery has two very different ratings, and I am also trying to reconcile the significant difference between the best and worst of these batteries.
Can you provide any insight?
From what I understand, BigBattery got a few complaints of these batteries not performing to their rating. Reviewers like Will Prowse and I both capacity tested the packs and got a lower capacity than advertised, so bigbattery did the right thing and adjusted their advertising to be accurate and honest. I think the 2.8 KWH figure is assuming grade A cells, which these packs are not built with. I had talked to Eric at BigBattery at one point and he had informed me that my pack that I made the videos on was a B-grade pack and those were the grade that they had the largest quantity of.
Hopefully this shines some insight.
"Grade A" is not an ISO term so it can mean anything the marketing department defines it to be. Same thing with Recertified or Remanufactured.Grade A cells sound like they are new, so it seems hard to understand how any of these batteries have "grade A" if they are made from used Nissan leaf cells.
I have never spoken to Eric but watching some videos and reading about him I have come to the conclusion that he has a gift for marketing.I had talked to Eric at BigBattery at one point.....
From my perspective, it was around when Will and I started to review these batteries in the earlier half of the year. If my memory serves me correctly, Will had brought up the valid point that the batteries were less than the advertising to bigbattery, and in my testing I did the same thing - Except I did this prior to releasing the video.Thanks, that helps.
Do you know when BB started showing lower ratings? Seems like it must have been fairly recent. Grade A cells sound like they are new, so it seems hard to understand how any of these batteries have "grade A" if they are made from used Nissan leaf cells.
I just tried googling your inverter, and I'm struggling, MPP Solar's site came up with a controller only, but based on your questions it sounds like it's an all in one unit. Do you know what series your inverter is?I need help configuring my MPP 5048 inverter to achieve the following:
1.0 I want only solar to charge my 48v Nissan leaf batteries
2.0 I want the inverter to only switch on utility when the battery voltage drops down to 48v
3.0 I want the inverter to switch back to battery when solar has charged battery to 57v
4.0 I want grid to be off during 3.0 above
1 - program 16 - OSOI need help configuring my MPP 5048 inverter to achieve the following:
1.0 I want only solar to charge my 48v Nissan leaf batteries
2.0 I want the inverter to only switch on utility when the battery voltage drops down to 48v
3.0 I want the inverter to switch back to battery when solar has charged battery to 57v
4.0 I want grid to be off during 3.0 above