Hehe... there's a saying:
Batteries don't die, they're murdered...

With regards to lithium batteries there have been (are) several flavours, some more able to handle abuse better than others. Lithium might make up only 10% of the whole battery. Additional components might include chromium or manganeze. But years ago research at the University of Texas developed the phosphate formulation of lithium battery usually written as LiFePO4:
http://en.wikipedia.o...

And this is what has the EV community (and others) excited. Yah you can still abuse and destroy the things, but they will NOT ignite. One tradeoff is a little less energy density than other lithium batts like the LiPo batts that are still popular with the RC (especially aircraft) crowd...

So if/when ya read stories about lithium fires, these are from folks that "don't know what time it is"!

tks
Loc

you are a wealth of information. Do you know anyone locally who specializes in LiFePO4? I am a low maintenance kinda guy so I would like to have things as simple as possible.

Do you know anyone locally who specializes in LiFePO4?

Not really. The folks I know online have settled in with Mr.Ping. One of the very few China-based sellers that has earned a reputation for good service:
http://www.pingbatter...

evcomponents are in the USA. They are fairly new at retail but the folks behind it are well known and respected in the EV community:
http://www.evcomponen...

Justin and the gang at ebikes.ca (home of the Current Analyst!) have a top-tier rep... many in the USA buy from Justin. And I see he's finally carrying some LiFePO4... you can be sure only after careful testing and selection...
http://www.ebikes.ca/...

...but I also see that Justin has gone w/triangular packs...

Still don't think you have said what size Ahs your batts are... 4x12V in series, so 48V system, but what size of batt??? Need to know how many Whs yer carrying around!

tks
locK

I am not sure - it just says 48V20AH Sealed Lead Acid Battery. I believe there are 4 of them.

I'll just wait when there is a local person who can do any upgrades. I don't feel comfortable to change electronics.

There ya go then... Ya have a 48V 20Ah pack...

Mr.Ping lists right now at $598US... 9.9Kg and in a package 195x210x150 mm

http://www.pingbatter...


evcomponents has a similar pack of Headways here at $699:
http://www.evcomponen...
290 x 206 x 160 mm or 380 x 165 x 137 mm and about 11.2kg



I'll bet many would pay the premium (they'll both add freight charges) for the Headways from evcomponents... Cause Headway has a better track record with the all-important BMS circuit that comes w/the pack. Also the new Headway cells now come w/screw terminals... MUCH better to work with if/as individual cells might need replacement... Ping is still spot welded tabs I believe...


Steveo up in Richmond Hill recently announced he is "open for business"... converting and upgrading... Would you trust this guy w/your beloved ebike?




Lock

Wow... Looks like a LiFePO4 pack would be knocking about 15kg or 33lbs off the weight of the bike...

Are these things plug and play? The second one looks scary.

Hehe...actually, it's the first one that looks scary! It's a "classic duct-tape" pack... For most of the last year folks that have been buying LiFePO4 packs (where they haven't bought individual cells plus a BMS) have been seeing packs like that wrapped in duct-tape. No kidding! And they are ugly things to deal with if they have to be taken apart to check the guts for any reason.

That Headway pack built up with a plastic rack/cell holder plus the screw terminals is a HUGE *improvement*! The latest Ping packs are described as "improved" and more "shrink-wrap" style in their coverings.

Yes, ya need to add your own case, for either flavour, Ping or Headway. Buy some sort of padded bag that'll fit around the pack and into your batt compartment on the ebike... or roll yer own. Just needs to be wrapped in something to cut vibrations or bumps and that is non-conductive.

While Lithium chemistries operate at diff.voltages (perhaps 3.3V nominal versus lead at (2Vx6) 12V, the Lithium packs are commonly made up so that the cells are connected in series and parallel that combine to produce output voltages that equal the "classic" combinations of lead batts as 24V and 36V and 48V. No reason for these increments *except* this means that they DO plug-in-play with standard electronics that are already designed for these voltages... The BMS on the pack is the interface between the pack and your controller. The controller doesn't know or care that the pack is lithium and not lead.

So yes, these 48V Lithium packs should plug right in. Ya likely would need to add the correct connector to the pack to mate up w/what you already have... or better yet take the opportunity to upgrade to Andersons (or Deans or Traxxas.)

Don't take my word for it. Tap with Steveo! (BTW, I have never had business dealing w/Steve myself. I only know him from his writings online, and (I and others) have seen the work he has done w/electronics eg building and upgrading his own Lithium BMSs and packs...)

You *would* also need to buy a proper Lithium charger, most likely. Unfortunately the charge regimes for lead and lithium are almost identical, but not quite. Some chargers come w/internal adjusters that can be tweaked to make `em work w/lithium, but many do not.

lOk

Here's a thread that's right up yer alley:
Has anyone bought from Evcomponents.com or use Headway 38120

L

My EVT 168 has 4 (Lead Acid) batteries @12V, 50AH . If I was to replace them with a LifePo pack from EVcomponents what would be the correct set-up using those LIthium packs? My EVT has a 1500 watt motor so will these batt's be able to handle the required current draw? My goal is to get a significant range extention.

Eric