PakTrakr interesting situation

The PakTrakr main display is telling that the pack won't charge more than 78% in this cold weather - but - when I look at the data on the SD Card from the Woodward large Pak Trakr Display with Data Logging, - I see the front remote data says that part of the pack is at 100%, and the rear remote says that part of the pack is at 100%, and - the individual battery chargers are saying each battery is charged to 100% and is stable at about 13.2 Volts, all leaves me wondering what happened?

Current Cold weather, wet & snowy weather, and work schedules make checking it all out a bit more difficult, and other issues of late to deal with have left little time or energy to dig into it!

Likely - my last thought of simply - take the car for a drive, keep the batteries out of the danger zine, and come back and put them right away on the charger is made more difficult due to the Rehab center customer stream that usually is in the way for me to plug in, except for Friday Afternoon and Saturday Afternoon. However - for some reason - this past Friday - there was a late night stream of clients to the center!

If the actual power consumption of my battery pack was measured from the beginning with the Data logging PakTrakr Display - I would have a tally of how many Watt hours I had taken from it - but the pack was driven for wome time with just the analog Voltmeter and Ammeter, so no real way to know! (And those trips where I drained the batteries and limpled along - both in warmer weather the first time, and in cold weather the second time, likely took a lot of life out of the set!)

In any case - we are seeing more and more places supplying and promoting LiFePO4 (Lithium Iron Phosphate) cells and packs for cars and eBikes too! Just looked today for a few minutes at San Diego Electric Bike. they have some good information there, and there was some other good stuff I will report on shortly!

Battery Self Discharge Monitoring

For the last couple weeks, I have had the car charged, and then parked it, monitoring the battery voltages by logging the current voltages after charging, (and making a note in my notebook log, as well as using the SD Card Data Logging function of the enhanced display), and then checking it and logging a few minutes every few days.

Today I moved the car back to the building for a while, to nake a parking spot avaialble while I was working on my aerocap project on the Dodge Dakota Pickup. The pack was showing 100% before moving, and dropped to 95% from the move, so it shows there is some power loss to self distribution over the last couple weeks, because the move was only about 50 feet.

Now that might just be the effect of Battery Number 2, which goes dead first on a driving run, or the cold weather, or both, or the actuall battery state of health. As of yet, State of Health (SOH) is something I don't have and hard monitoring on, just inference from the total or part pack State of Charge (SOC), and individual Battery Voltages at rest or under load, in comparison to the others.