Saturday, December 12, 2009

Heating Things Up

So after doing a few more Zilla runs, including the worst hill in my commute and ripping up it like nobody's business, I decided to take a good look at my heating.

So these past few days I have used my AC ceramic heater and tested out the capability of them.

It was 27F outside and with the Heater set to MAX, the car was fully defrosted in 8 minutes and 42F, in 15 minutes it was 50F and after 20 minutes it was a nice 58F inside!

I have decided to do the heating right and get the AC drained so I can install my ceramic heater core into the old heater core socket. I still have an AC heater for preheating/defrosting, but I full 1500 watt heater in the EV would be a wise thing. It will use about 15 AMPs, which isn't really that bad. I just need to find a shop to drain my AC so I can work on the installation.

I have also decided that I want to get Lithium batteries for my next set, so I have already started to save up. I am looking at 30 cell of TS-LFP100 from Thundersky, and it should give me 35 miles of range. It looks like that will cost about $3,300 which does sound like a lot, but when I looked at a higher quality/power lead acid pack, I found it would cost about $2500 for that kind of range and twice the weight with 1/10 the cycle life. I have lots of saving and research ahead of me to do.


Margus Väli said...

Thunder sky units specify max current as 3C, which means 300 amps max for lfp-100. This is way underpowered for you, either raise the voltage or go with LFP 160 or similar.

David Harrington said...

Nothing is set in stone yet, like most of this EV.

I rarely pull more than 250 AMPS when accelerating, so 300 may work. I would like 160 Ah batteries, but now we are talking $5200 vs $3300, a major difference.

I was also considering the Sky Energy 120 Ah, which specify 4C max, which would mean the same peak as the 160 Ah TS cells.

Two years ago there lithium was old out reach. Now there are so many options it's intimidating.

Electro_Steph said...

The charger & BMS for the Li-Fe batteries is also not cheap. What are you planning to use as charger?

David Harrington said...

I am working on my own BMS system and my current old school charger should would with LiFePO4 because it is a Constant Current, Constant Voltage charger. I will just have my BMS shutdown the charger when the High Voltage Cutoff of the batteries is reached.