Recent content by BroomJM

I had cycled this battery dozens of times over the last 6 months, in the 30% - 100% range, with deviation between (pairs of) cells no more than 10-20mv. It just suddenly had one pair of cells drop to 2.5 volts, while the others were at 3.25 to 3.3 volts. It was like only that one pair of cells...

I recently had a 2nd-life battery do something weird. The BMS shut down the discharge because one of the cells (it's a 2P-4S, 240AH, FLP battery, so technically it was 2 of the 8 cells) went to 2.3 volts. The other cells were all closer to 3.3 volts. I thought for sure something had gotten...

Have you used one of the battery equalizers? I have four 12v, 100AH batteries. I have them connected in series pairs to make two 24v, 100AH batteries. These are then connected to a bus bar. I have learned the lesson about batteries not staying in balance, when connected this way. When I...

I recently built a 4S-9P battery, using 2nd life 26650 LFP cells. I tested and grouped them prior to building the pack, choosing only the best cells so that the capacity and resistance were very similar, for each of the parallel strings. I was very confident in the pack when I sealed it all...

They are two sets of 12v, 100AH, LiFePO4 batteries. One is a set of Power Queen batteries and the other two are 4S packs I built a year or two ago, but with no more than maybe 25 cycles on them.

Below is a picture of a 24v (2P-2S) system I just set up. Note that the battery switch is in the "OFF" position. I have not yet wired the solar or AC, incoming or outgoing. I am not sure it's safe to turn the battery switch to the "ON" position before precharging the capacitors. I have a...

Yeah, I wouldn't even think of doing this with lead acid...I should have specified LFP and individual BMS's for each battery in my original post. Per the video posted of Will doing exactly what I asked about, it seems that you can do this, but you really want to be precise with your cable runs...

"(Safe to do, but not the best)" I guess that about explains it.

This has always been my understanding, as well, but if the battery with lower capacity is topped off, and the BMS cuts off charging, wouldn't the current supplied to the bus bar continue charging the higher capacity battery until its BMS stops allowing it in? If your solar array is still live...

I know when you connect two batteries in parallel, they should be the same voltage, and you should verify they are at roughly the same state of charge so there isn't a huge inrush of current from one battery to another. In my research on this, it seems that the voltage is crucial, but state of...

Regarding your last two comments: I have used a lot of 12 and 24 volt devices during my lifetime, mostly in the camping and boating world. I know that many of the things we plug into AC ultimately run off a DC motor or circuit. Edison was (obviously) a genius and recognized the advantages of...

Well, that sucks, but thanks for verifying it's not just me doing something stupid. :)

I'm using a couple of 100ah LFP batteries I built 2 years ago to power a small DC fridge. Once the fridge is at temperature, the draw on the batteries is very low, meaning under 5 amps worth of draw. I know from prior experience that the Daly BMS on these batteries doesn't "wake up" for less...

I'm afraid you're right. I'll have to look and see if it's still under warranty.