It’s November 27th, 2020, how is Orange County Florida doing with COVID-19?

The rate of  new cases had a slight rise in September, and continues to be on a slight upward trend in October. This upward trend accelerated in November. Orange County is averaging 469 confirmed new cases per day over the last two weeks (compared to 224 in the same period in October). While not quite as bad as the summer peak of 600-800 per day in July, these numbers are  going in the wrong direction.

We had 96 people die from Covid-19 in Orange County in the last month (slightly better than the 105 in the prior month) and the total death count is at 642.
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Electronics & Surplus suppliers with fast shipping times to Florida

Here is a list of suppliers located close to or in Florida, for fast shipping times:

  • Industrial Safety Products – Miami FL – Personal Protective Equipment.
  • MPJA.com – West Palm Beach FL – Surplus & Closeout electronics, motors, chemicals & tools.

Other useful suppliers located farther away:

  • All Electronics – California – Like MPJA, but with an even wider selection.
  • American Science & Surplus  – Chicago, IL – A more random selection including a lots of crafts, outdoors, optics, novelty, etc…

EGO 7.5AH Battery degradation over time (3 year mark)

I log how much power it takes to charge my Ego batteries after I use them. I’m using this as a stand-in for how much capacity they retain over time. You should know that I have a large lawn (in Florida) and cycle these batteries at least once a week (more in the summer) so these batteries are getting more of a workout than if you had a small city lot that you could mow a few times before charging the battery.

I have two 7.5 AH batteries (one bought before the other). They took 410 watt hours to recharge when new.  My older battery has three years of use, and has 63% of it’s original capacity (260 w/h).   The drop from year 2 to year 3 was from 75->63% [The batteries have a 3 year warranty, so the first battery is now out of warranty.]

My second battery appears to be following the same general trajectory, although it’s capacity is just slightly less than the first battery (at the same years in service mark).

For the bar chart above I averaged the capacity of all measurements in a particular year, but if you graph all measurements you can see that they are generally decreasing over time (although the batteries do sometimes go “up” in capacity, possibly due to ambient temperatures).  The following graph is for my 2nd 7.5AH battery (manufacture date of 2018).

Judging the balance of cells within a battery based upon ending charge profile

My S-10 EV conversion has a battery pack made up of Nissan Leaf modules. I am using a mini-bms system which has a per-cell alarm, but does not report per-cell voltages and also does not do a great job keeping the cells balanced.  To check individual cell voltages, or manually balance cells, I need to pull a few pins and lift up the tilt bed on the back of the truck.  But it is possible to determine when cells in the battery are no longer well balanced based upon the power draw when the ending voltage is reached. You can see this most easily by looking at the charge profile graphs (provided by my JuiceBox EVSE).

When the cells are not balanced, some cells are at a lower SOC than others when the ending voltage is reached, which results in the entire pack drawing more power (in this case, charging ended when the max voltage cutoff was reached, but the pack was still drawing 3,000 watts.

After balancing the cells, the normal charging profile looks like this:

As you can see, the amp/power draw slowly tapers off as the max voltage is approached, and the pack is drawing less than 1,000 watts when the cells are balanced.

I use these end-of-charge graphs to determine when it is time to pop the back of the truck and manually check/balance individual cells. [I still have the mini-bms units to automatically stop the charger if any cells voltage goes too high, or alarm if any cells voltage goes too low.]

First Alert Smoke Alarm with Voice SA511 short service life (Malfunction signal)

In 2017, I purchased six First Alert Smoke Alarms with Voice (Model SA511) for our house. These are battery powered units that run for about a year before the 2 AA’s need to be replaced.

Sometime in the past  (late 2018? 2019?) one of them kept false alarming, and no amount of compressed air, battery changes, resetting, etc would keep it from alarming, so after several calls to First Alert, they replaced it under warranty.

More recently, (in June 2020 and November 2020) the units in my garage and utility room off of the garage both failed with a “Detector Error in <location>. Check Manual” error message (followed by three short “berrps” in rapid succession).

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Lenovo Smart TAB M10 does not work with WPA2 and Android 9

To summarize why I do not recommend buying a Lenovo Android tablet:

  1. Their Android 9 software update borked WPA2 support.
  2. Instead of figuring out the (software) problem and fixing it, they instead instruct their customers to downgrade the security of their wifi.
  3. If that doesn’t work, they RMA the tablet and flash an older (insecure) version of android on it, and disallow software updates.

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October 28th 2020: Orange County Florida COVID-19 Report

It’s October 28th, 2020, how is Orange County Florida doing with COVID-19?

The rate of decline in new cases had grown sluggish at the end of August, plateaued and then had a slight rise in September, and continues to be on a slight upward trend in October. Orange County is averaging 224 confirmed new cases per day over the last two weeks (compared to 147 in the same period in September). Compared to an average of 14 new cases per day in the first two weeks of April, the number of people infected each day is 16 times higher than in April.

We had 105 people die from Covid-19 in Orange County in the last month (slightly worse than the 79 in the prior month) and the total death count is at 549. Continue reading

September 27th 2020: Orange County Florida COVID-19 Report

It’s September 27th, 2020, how is Orange County Florida doing with COVID-19?

The rate of decline in new cases had grown sluggish at the end of August, plateaued and then had a slight rise in September.  Orange County is averaging 147 confirmed new cases per day over the last two weeks, compared to an average of 14 new cases per day in the first two weeks of April, so the number of people infected each day is still about 10 times higher than in April.

(You can ignore that 7 day hump at the beginning of September….a large lab reported a backlog of positive tests all at once.)
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Giving away public Wifi with DD-WRT and VPN

Cliff Notes for setting up a public (unencrypted) wifi hotspot to give free internet to guests with minimal risk to “your” network.

Sometimes it’s nice to give people free wifi, especially if you have more bandwidth than you normally use. However, you don’t want random people being able to access your network (or their random network activity to be traced TO your network….)  This is my set of notes for how to set up a 2nd wifi router (which must support the DD-WRT firmware) to act as a free wifi hotspot to untrusted guests.
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