Electric vehicle batteries and chargers

I'm buying an XM-3500li and adding an additional 4 cells for a total of 24 cells. I need a good and inexpensive BMS to maintain the batteries. I've heard lots of talk about the goodrum/fetcher BMS, but I can't find one for sale anymore.

Rechareable Lithium Power has a ready-to-use one for $230, but they're out of stock.

TPpacks has the bare circuit board with a list of components that you need to buy and solder yourself, but they're also out of stock.

I would prefer to buy a premade one, but I have the skills to build it myself if necessary. Does anyone have a link to a place I can buy one?

Thanks!

Hi,

It took me a while but here is my first post, i hope its in the right section of the site so here we go.

I did check the site and found loads of info already on the subject, but then again,nothing applies to the bike i have.
That and its all a bit too technical, im a beginner in these things so when explaining, be patient with me.
See it as " adding power for dummies" as i am one :) I have asked a few local people here who claim to know but further then sparking batteries and no good advice, i don't seem to get.

I own a Electric Bike, Luyuan i believe it is, similar to Condor / Mountaineer or other types out there, sort of 1 bike fits all.

It has a 48v battery pack in it( 4 x 12v/12ah) and 1 x 250w motor. It motor's fine at 18mph but when I'm near a hill, i might as well get off and walk as its slow, add factors such as wind and rain and i can stay there for the night.

I'm prepared for a couple of options,

A : i purchased 4 new batteries to add , but somehow that didn't bring anything.
As advised by some of the members here ( thank you all for your help so far ) i've connected the new batteries in series, duplicating te existing battery pack.
Then i wired it up to the connection point, be it " red with red and blue with blue, from pack 1 too pack 2 ".. no sparks, no smoke ( woehoeew)but also no added power ( d'0h)
as said, im new at this and im willing to try so im not sure , have i wired it wrong or what happened, as i didn't give me more power to start from a full stop, or to go up a glorified speedramp, nor did it add some speed , but the torque is what im after mostely.

B :i have seen some mod's here that just added 1x 12v battery , to make it 60 v, and have the same effect as with the shunt, question is,how do you wire that too the bike/batteries and will this not blow my motor/controller or any of my light bulbs? if you have an advice, please feel free , chip in and tell me, as i am getting desperate.

C: the shunt.. "bin" there , done that.. fried the controller and some cables.. so won't try that again.

I have new batteries sitting here, waiting to be used, so i can use any kind of help that is out there.
As i live in Europe, and E biking here is not really big (yet) , i am on my own - same for Forums.

i love the bike, greatest thing ever but now its a " fair weather " bike, to use when there is no wind only..this time of the year , proven to be hard..Its a daily struggle.

I went that far with adding the pedals to the bike, so when uphill , i pedal.. according to the police stopping me this evening , i looked like i've lost my marbles, great laugh he said but not to do it again as it would distract other drivers around me :) off with the pedals it is.

As said, im aware that these topics are all over the site but they make no sense to me so i hope that someone out there can give me a hand , hopefully with good results.

Many thanks

Joe

I have a 24v 15a lithium battery in a case and I want to put a voltage cutoff switch on it so that it can't spark when I reseat it on the bike after charging.

I found this switch on e-bay that is rated for 20a: http://cgi.ebay.com/ebaymotors/Heavy-Duty-20-amp-Toggle-Switch-with-Waterproof-Boot_W0QQcmdZViewItemQQhashZitem439aaa64edQQitemZ...

I plan to run the positive power lead from the battery to the switch and then on to the fuse at the contact point where power is transferred to the bike. I can't reach the fuse before the switch due to the fuse mounting spot, but I could insert an in-line fuse before the switch.

Should the switch do the job I want?

Should I add an in-line fuse for protection?

Hi All

I have an EVT 4000e...I installed new batteries 3 months ago and was getting roughly 45km per full charge.Then EVT was on empty for a few days as a fuse had gone and I hadn't realised. I was half pushing it half riding it (beeping and cutting all the way) around Paris from one electric point to the other in a bid to isolate the problem. I finally realised that it was a blown fuse causing the charging process not to work. Amateur! Now I get around 25-30 KM maximum per charge!! Is it possible that I've damaged the batteries already?? I have some battery equalisers but they aren't installed as I'm waiting for a friend to install them...maybe I can put the equalisers in there to get more distance? Here's a link to the equalisers.

http://www.powercharge.dk/default.asp?lang=en

Click on 'products' then 'battery optimizer'

How do I use a volt meter to establish if there is a problem of imbalance ? And what kind of volt meter do I need to buy.

I'm sorry, I'm a novice when it come to electronics and EVs. Trying to learn as quickly as possible.

Thanks in advance for any help.

When I first heard of X-treme's plan to sell LiFePO4 bikes w/o BMS's I shook my head in disbelief. But there are several on V who bought those bikes and here's one person chiming in a year later saying "not a problem".

xb-700li 1 year later

It seems therefore this group has some experience we can share about using LiFePO4 in real world situations. A few questions that come to mind are

• What precaution exists on X-treme's bikes for undervoltage? I assume overvoltage precaution is done by the charger.
• Have any of the owners monitored back balance? Observations?
• Have any of the owners added BMS systems?

I could not stand it any longer and opened one up: It has a iron (ferrite??) cylinder inside it, nothing else.

The cylinder is mounted around both the positive and the negative cable.

What is it for?

What would happen without it?

I took one look at the picture and saw batteries wrapped in duct tape and a home made charger! This thing screams in my eyes FIRE. Please take a look for your self.LiFePO4-48V-20AH-Electric-Scooter-E-Bike-Battery-power

I purchased a duct tape 48V LiFePO4 20Ah battery from Cammy CC on eBay. I had some initial charger problems and she replaced the charger several times. I had a working charger and I was loving it. My electric bike was powering me up these steep hills in Pennsylvania. Then it rained for a week so I didn't ride and I left my battery off the charger. When then rain stopped I plugged back in the battery and it got a good 24 hour charge. When I plugged it into my bike the light on my controller came on for a second then went right out. I emailed Cammy and she told me to check the voltage of the battery and the charger. The battery was a steady 50 volts after a 24 hour charge and the charger was a steady 55 volts. She told me the charger should read 60 volts and the battery when fully charged should read just over 60 then drop down to 53 when fully charged. So it appears my charger isn't charging my battery fully. Is there anyway I can fix my charger or does anyone know where I can get a good charger for cheap? I have several of these lame-duck chargers and they all test at 55 volts. I need something that can put out the juice. These hills are killing me without the powered assist. Thanks.

This is WAY off topic but I am looking for a low output charger to use as a maintainance charger for a 7-6v golf cart battery bank. Something to leave on when not being used. Any ideas or directions I might look??

Jim

This is WAY off topic but I am looking for a low output charger to use as a maintainance charger for a 7-6v golf cart battery bank. Something to leave on when not being used. Any ideas or directions I might look??

Jim