Recent content by mberding

Update for any that are watching: Did a test yesterday after holding at 13.6-ish for a couple days. Instead of hitting OVP at 13.9, they're now at 14.2. Going to leave it balancing for another couple days (or more?), really hoping for a OVP of 14.4 or better.

Agreed, and since this user only occasionally gets shore power, it'll never be long term. The DC-DC and Solar charge controllers are a bit smarter and will drop their voltages a bit. I think these batteries are so bad that they're in OVP at 13.5-ish. When the inverter kicks in, the voltage...

The cells were top balanced before being assembled with a desktop charger. They're exceedingly crappy cells though and won't maintain balance through even a single cycle, so OVP kicks in way too early, all the time.

I guess I'm just surprised that a charging source would spike so high so quickly. Seeing 19v (even if just for an instant) is really not expected when the charger is supposed to be putting out 14.4 Agreed, in theory, but if your solar charge controller is always running unless you manually...

Agreed, I'm all about the Victron equipment for every application and system these days. The cheap stuff just isn't worth it.

It's only spiking right now if the inverter has some kind of draw. Otherwise the system seems to be sitting perfectly happen at 14.-something volts. To clarify, this inverter is very simple and doesn't have a shore power input concept. It's just a 12v DC to 120v AC inverter. There's a...

This makes sense when used with a charge controller, since it's designed to put power into a battery. My question here is, am I crazy thinking the inverter is sending it's excess 12v power back from the inverter to the batteries when it decides it doesn't need it? With regards to top-balancing...

Let's set up the situation: A charger is running (could be solar, DC-DC, or shore power) and is outputting 14.something volts (generally 14.2 or 14.4 depending on charger) All batteries are in over-voltage protection mode (because they're sucky grade B cells and no amount of top-balancing will...

I just figured these things were done ahead of time. In your opinion: How long should it take to balance the cells (via BMS) in a 100ah 12v pack? (And I'm working blind here because the the LiTime BMS doesn't have bluetooth, so I can't see what's going on.)

I don't have the equipment to do a capacity test, unfortunately. And I need this system for its intended purpose to NOT be in over-voltage condition at 14.4 volts as it has to be able to absorb some amount of power while at that voltage.

Yes, I was just providing a clarification to my original statement. And without Bluetooth on this particular battery I purchased, I have no way of knowing what the voltage spread is, so I'm blindly trying to top-balance for who-knows-how-long.

Yep, I know. I'm just being impatient with this battery because I was expecting it to be fully functional when I bought it instead of needing babysitting and an extended install process.

Without the bluetooth BMS, I'm guessing at what the voltage is where it'll start balancing. And is that single-cell voltage, or minimum cell voltage? No way to know since it's a sealed black box. So in your opinion -- how long do you think it'll take to balance out one or more cells in a 12v...

Agreed -- The 48v batteries I've built myself have bluetooth BMS's, and I can check and see what's going on. The 12v batteries I've built lately have bluetooth BMS's. I was trying to just buy something off the shelf and have it work so I didn't have to build my own. That didn't work out so...

OK, that sounds pretty much like what I'm doing right now with my desktop charger. I can set it to exactly whatever voltage I want and tinker as needed. And I've already been doing the "fun part", trying to figure out how high I can set the voltage without having it trip into over-voltage...