105 posts / 0 new
Last post
Mucus72
Mucus72's picture
Offline
Last seen: 1 year 11 months ago
Joined: 17/04/2014
Li Ion batteries

There are increasing numbers of motorbike batteries using Li ion that are really light. There is one on eBay right now which is 775g. Versus about 8kg for a Banner. This is serious weight loss. What is the advice here if any of you have experience please?

 

Jonathan Kay
Jonathan Kay's picture
Online
Last seen: 2 min 48 sec ago
Joined: 17/04/2014

There's a lot on this in the archives. My summary:

  1. There are now several happy Members. They seem to work fine in 7s and cold weather (by UK standards) hasn't been a problem.
  2. They're very light and very expensive.

I'd be prepared to fit one, but don't think they're worth it... yet. I'd be very wary of one that didn't have known provenance and previous reports.

Jonathan

 

Mucus72
Mucus72's picture
Offline
Last seen: 1 year 11 months ago
Joined: 17/04/2014

Thanks JK. Some of these batteries are in the price range of £75-£100. I’d say that’s amazing price for a considerable weight loss. More and more seem to be flooding into the market. Feedback I’ve had for cold starts is to prewarm by turning on your headlights for a bunch of seconds first. I’d also want a slick bracket/clamp for it. 

Mucus72
Mucus72's picture
Offline
Last seen: 1 year 11 months ago
Joined: 17/04/2014

Thanks JK. Some of these batteries are in the price range of £75-£100. I’d say that’s amazing price for a considerable weight loss. More and more seem to be flooding into the market. Feedback I’ve had for cold starts is to prewarm by turning on your headlights for a bunch of seconds first. I’d also want a slick bracket/clamp for it. 

Frosty
Frosty's picture
Offline
Last seen: 2 years 6 months ago
Joined: 06/10/2017

What do people make of this product:

http://www.kitcardirect.co.uk/ultrabatt-lithium-battery-728-grams.html

I couldn’t see any technical data for the battery.  Jonathan, could you advise on what Ah battery one would need for a 2.0l Duratec fitted with a isolator/battery master switch? Occasional weekend/dry weather use, currently stored in the garage over the winter and fired up for a short run up to temp about once a month.

Kind regards,

Frosty

Superlight R500 Duratec

Jonathan Kay
Jonathan Kay's picture
Online
Last seen: 2 min 48 sec ago
Joined: 17/04/2014

I don't have a good answer, but let's see if we can creep up on that.

But first the warnings:

  1. The two widely quoted figures represent the amount of energy deliverable from the battery, typically measured in Ah (happy to argue about units and whether this is "energy" or "charge"), and the maximum current that can be delivered eg at cranking, typically measured in A. But I don't think that the way these are measured is particularly consistent between manufacturers, I have never seen an independent test for this sort of battery, and at least two suppliers actually use incorrect (rather then merely deprecated) units. 
  2. Current drain at rest varies considerably between 7s. And some 7s live on *conditioning chargers, some have isolator switches, and some use nothing at all: this is crucial when considering how much energy needs to be stored and Andrew has worked through some of the numbers.

Here goes:

  1. The Magneti Marelli MM-ION-15 is rated at 32 Ah and 540 A cranking.
  2. The Varley Lithium Li5 is rated at 5.5 Ah and 335 A cranking.
  3. What battery do Caterham fit for your sort of Duratec? I'll then look up the spec for that.

Jonathan

​* Some conditioning chargers now claim to be optimised for lithium batteries, but I don't know how much this matters.

Frosty
Frosty's picture
Offline
Last seen: 2 years 6 months ago
Joined: 06/10/2017

Thanks for looking into this Jonathan... My car currently has a Banner battery fitted, although I can’t get you the current spec as I’m out of the country at present but will be able to look soon.  The car is a 2009 R500 Duratec however I’m not the first owner, I purchased it in September 2017 from Caterham as an approved used Seven.

If there are any recommended batteries for a reasonable price I’d consider swapping to something lighter in mass, just so long as it is a suitable spec and can be securely held in place.

Frosty

Superlight R500 Duratec

OliverSedlacek
OliverSedlacek's picture
Offline
Last seen: 2 years 7 months ago
Joined: 17/04/2014

I'm really pleased with my Skyrich 15Ah Lithium battery, which only cost £150 ish from memory. Mind you, with no immobiliser on my trusty XFlow I don't have a problem leaving it for weeks anyway. An isolator switch might be good on a more modern car, but the weight saving per £ is unbeatable.

Geoff Brown
Geoff Brown's picture
Offline
Last seen: 42 min 5 sec ago
Joined: 17/04/2014

Current Banner is 35Ahr

7 wonders of th...
Online
Last seen: 2 min 26 sec ago
Joined: 17/04/2014
Jonathan Kay
Jonathan Kay's picture
Online
Last seen: 2 min 48 sec ago
Joined: 17/04/2014

The Magneti Marelli MM-ION-15 is rated at 32 Ah and 540 A cranking.
The Varley Lithium Li5 is rated at 5.5 Ah and 335 A cranking.

Skyrich YT9B-BS / HJT9B-FP-S: 15 Ah, 190A.
JMT Lithium Ion Battery HJTX20H-FP: 7 Ah, 420 A.

The storage capacity on the Varley and Skyrich look low. Any experiences in practice, please, with details of how the 7 is kept, see post #6? (Thanks, Oliver.)

Jonathan

PS: To the tune of "If I had a Hammer"... "If we had a wiki... "