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…

How did 12-volt battery systems become the norm?

Perhaps the most significant change in this project is the use of a 48-volt battery bank.  There are a number of reasons for this, and we’re going to discuss them before looking at a new configuration.  Here though, we’re going to start with why we have what we have: an electrical system designed around 6…

New Project: Installation of a New Lithium-Ion House Battery Bank

Here goes nothing!  After a lot of planning, and several revisions, it’s happening.  I’ve started the process of replacing an aged house battery bank and inverter/charger with a new system based around lithium battery technology. This isn’t going to be a simple remove-and-replace project though.  While there are a number of commercial offerings already available…