[RedDevil]

Three commutes on the new charge all run with the lamp shunt, batteries still at 39.4 Volt each.

Using the lamps I get one check IMA error per day, or none. Usually when keyed off and on within seconds - typically at the lights, supposed to stay red for a long time, engine does not AutoStop, I key off and the lights go green at the same moment, jumping 3 lanes in their usual cycle .

Other than that, the lamps seem to solve the problem in a crude way. Crude as the support remains tiny with the limited current.
I do need to be able to switch them in and out, I want to order another relay together with a bunch of LCD displays and some shrink sleeve (can't have enough of that!)...

My economy remains about the same as before I started using the packs.
What is different is the weather. Temperatures plummeted from Indian summer like to near freezing all day. Still getting around 60 mpg on my commute is quite something, especially considering I lost my upper grill block in a gale a few weeks back.

Cold charging?
Right now I'm recharging the packs for the second time.
This time I took them in, as it is too cold to stay in the shed for long.

Hooked up with the charger, two packs jumped to 40.6 Volt - but one went as high as 41.1!
Oh beep, do I have a bad cell or what?

I unscrew the lid and test each cell for voltage. Hard as the iron box is almost too cold to handle.
Hm, the cells are pretty much even. And the whole bunch now shows 40.9, still charging.... and goes down to 40.8, still charging???

The other subpacks are at 40.7 Volt now.
Their iron boxes are cold too - but just a little less...
The coldest pack had been sitting in the car in the toolbox together with the other two, but closest to the upwind side of the car. So it was just a few degrees colder that the other two, and that was enough to increase its internal resistance substantially!

So, while the effect on my economy is not really impressive this far, I'm very glad with the pack being portable. As charging them around or below the freezing point is apparently a bad idea; being able to take them inside the house solves that.

Below 10°C / 50°F the internal resistance rises quickly on charging.
Do not charge LiFePO4 when cold - CONFIRMED!