I mentioned in the previous post that a new battery monitoring system was going to be built to allow use of run-of-the-mill charging equipment, and that it’s cost would be less than $100. It’s also going to be internet connected–we’ll be able to log state of charge, voltage, and a number of other performance metrics…
Category: Main
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Buying the Hardware
Here’s where things start to get pretty interesting–and where money really starts leaving never to be seen again. I’ve talked briefly about the battery pack itself, and still plan to write more about that decision process, but it’s in-hand and looks well suited to do the job. That’s the easy part. Now we’re into figuring…
Home-Brew Macerator Pump
I’m taking a little break from the lithium battery project today. Usually I don’t stray from hookups long enough to worry about emptying my waste tanks–it helps that I can handle 75 gallons down the toilet, and another 150 gallons of grey water–but for the first time in 10 years, I needed to empty my…
What am I trying to accomplish?
It’s probably about time to talk about what I’m trying to accomplish with this project, and why I didn’t just replace my aging lead acid batteries. That would have been easy, but not much of an improvement.
A Few Observations on Battery Performance
This post is going to deviate a little bit from my typically long-winded format and present a list of observations and measurements so far. In short, I’m very pleased: The charger charges at a constant rate until it reaches the upper voltage shutoff After shutting off the charger, voltage drops by less than 0.2V (in…
Charging a 48V Volt Battery Section
Now’s where it starts to get interesting. We’ve got a bunch of 48V batteries that need charged. We’re sitting at 43.8V, after who knows how long between the donor Volt’s death plus 2 and a half months of storage. Do we really have a good battery? I’m going to save the details of how we’re…
Taking Apart a Volt Battery
Ok, I know we’ve put a lot of text up with very few pictures. This is where we start actually doing stuff and seeing what we’ve got. This particular battery was purchased from a large recycler near Dallas, Texas, back in October. I was in the area ahead of my first triathlon, and thought that…
Why a Volt?
If you’ve been following along, you’ve seen why we want to make use of a 48V battery pack. Now the question is a matter of where or how to get and/or build one. There are three pretty obvious choices here: Buy prismatic lithium iron phosphate (LFP) cells, connecting 16 cells in series. This would be…
Why does a 48-volt battery bank make sense?
Before deciding to use a Chevy Volt as a battery source, the plan was already going to make the switch to 48 volts. We’ve talked about why the RV industry settled in on 12-volt house systems; now we’re going to look at what might be better. What are some of the considerations when looking at…
A few words on Wire Sizing and Voltage Drop Calculations
Wire sizing guides leave out a part of the calculation important for figuring out the right size wire to use, particularly when dealing with low-voltage circuits where voltage drop can be a significant fraction of the total. Standard practice is to use Ohm’s Law to calculate the current needed by a device, and look up…