Archive for January, 2017

Battery pack requirements

Wednesday, January 4th, 2017

So, so more thoughts on the new pack.  I don’t want to have liquid cooling – I’ve already got enough problems with cooling the motor and controller. This takes out the Tesla batteries as well as the Volt/Bolt batteries.  Also, it just doesn’t get as hot in Santa Cruz as it does in San Diego.

However, it does get cold – we’ve had near freezing weather for the last few weeks, and that is not good for driveability (or for the number of amps you can draw).

So I’ll have to heat the pack somehow – this will be built into the pack from the start this time. My thought is to use some kind of ceramic heating pad (gardening shop here I come) under the batteries.

I also want a full-fledged BMS this time as well – the miniBMS did what it promised (tell me when something is wrong but nothing else) – but that isn’t good enough. I need to know which cell is failing, and to be able to do trending on the cells’ capabilities.

Research continues!

Brakes

Tuesday, January 3rd, 2017

I’ve been driving the 914 for 11,000 miles. The current controller does not let me do regen, so I’ve been having to use the brakes.

The 914 is currently in the shop to get all of the brake pads and rotors replaced. They also discovered that the rear calipers were frozen, and one needed to be replaced. *sigh*

Note: this was a draft I had forgotten to post, so this is about a year old – sorry.

Time for new batteries

Tuesday, January 3rd, 2017

The pack is about 8 years old, and was subject to a lot of hot weather (over 100F/38C). Several cells have gone bad, and it is not possible to buy the blue CALB 60AH batteries any more.

I’m investigating different technologies – CALB, Leaf, and Volt. Tesla would be lovely, but I’m not a rich guy. 🙂