LiFePO4 Battery

 

TL;DR save 6 kg, get the JWM battery

 

The standard lead-acid battery weighs 8.2kg.  A LiFePO4 upgrade is the easiest and cheapest way to save weight.

 

As the JWM PS-12 CATERHAM battery kit couldn't(*) be sent from UK to Belgium due to the "dangerous goods" nature of Lithium batteries, I got a Shido LIX30L-BS Quattro for ~260€ instead. 

 

Shido is a brand of the AFAM-Group, a belgian company (nice), but no country of origin is to be found on the battery or its packaging. Lite Blox of Germany is the place to go if you mean serious business with serious cash.

 

On paper, the Shido Quattro has the same format as the stock battery, and features 4 posts that let you orient it to get the desired polarity.

It weighs only 2.0kg.  As it is a bit narrower and shorter I've had to design and 3D-print some spacers for a perfect fit. You can download the parts on Thingiverse.

Regarding the charge, the car provides an ideal regulated 14V with the alternator, there is nothing to worry about. This is a 4 cells unit. LiFePo4 cells have a nominal voltage of 3.2V and should be charged at 3.5V, never exceeding 3.65V. On the other hand, if you let it go flat or need to trickle charge during long periods, a dedicated charger is required, simply because standard lead-acid and AGM chargers will go north of 15V.

On the picture you can also see the motorcycle cut-off switch (it weighs 36g and was installed on June 13th).

(*) JWM batteries update : (Oct 21st) I just got an e-mail from JWM telling me that their products are now carried by Mardi Gras Motorsport that are able to supply them to the European Union. Good news, a bit late for me. I would probably go for their £240 Caterham specific kit if I wasn't already equipped with the Shido.