Can I remove or adjust the BMS in my LiFePo pack?

[shirley_hkg]

A123 is still the most reliable .

Old stock is still found in the market .

This 5C pouch original factory assembled 12V 200Ah pack costs £350.00

[grazy+1949]

Thank you so much guys for all the info you have given me. I appreciate you sharing your knowledge.

Is the Cellpro PL8v2 the best intelligent charger for my application and , if I need to buy a power supply as well, which one do I need?

I am currently looking into sourcing 500w to 1000w BLDC single axle hub motors, supplied with either 10" or 12" alloy rims. I have seen single axle hub motors without rims, but I don't want to by the hub motors and then have to search for compatible rims. If anybody has a link , please let me have it.

Scrapping the BMS

Please can you help me make sense of what to do with these cables pictured below, in preparation for the intelligent charger.

[shirley_hkg]

9 wires . Good . That's completed .

[Burgerman]

There should be 9 wires, not 8. Those go to the PL8 balance ports.

Also saying

500w to 1000w BLDC single axle hub motors

Says almost nothing useful at all. Nothing about how powerful, or how much torque, RPM, or how much stall current, or what the free running current is etc.

800 to 1200 watt motor.
Size of an egg, for hobby use. Very low impedance.
https://alienpowersystem.com/shop/brush ... kv-12000w/

1000 watt motor.
https://www.alibaba.com/product-detail/ ... 24174.html
About 9 inches diameter. And 15 inches long.
Totally different current, totally different torque and RPM, totally different free running and stall currents.

Take a 250W wheelchair motor. Add some fins, and a fan. It makes the same power as before, same stall current, same torque, but now its a 350W motor.

A direct drive hub motor is great at speed.But low on torque, high on current at low speeds. You need to be looking at geared ones.

[shirley_hkg]

Willchair2 ia a good sample and inspirational.
It is brutally abused , but survived .

[grazy+1949]

24v 75 Ah LiFePo battery pack

Please be specific .... Do you have a link to the specs?

Hi Woodygb, The battery pack came with a single seater golf buggy and has no spec of any kind with the vehicle , on the casing or inside the casing. All I know is that it is made up of 8 layers ea. of 16 Heter cells (26 mm DIA by 65 long). The cells are arranged in such away within the battery pack that only info that can be read is: "Heter Battery".


grazy1949

[flagman1776]

I bought a generic liFePO4 pack for my TravelScoot rated the same 10AH as the official LI pack. When the BMS failed after a few months of use, I undertook a salvage operation. I found 8 series groups of 3 unmarked cells. I removed the BMS board. I had to rework the large power positive & negative leads. There was a series of small wires to the BMS board via a plug in... these are my balance leads. I adapted the balance leads to my smart charger. (I used the now obsolete Hyperion but today I'd use the PL8V2) Remember these wires are "live" so don't short anything. I now have 6 years on this pack & still going strong.

NOTE: I bought a pack of equal power to the OEM pack so my output was similar. Surely maker of the golf buggy have specs for a lead battery option.

[woodygb]

There should be 9 wires, not 8.

A count of the wires in the pic gives me 9 ...thus I assume a miscount by Crazy.

[flagman1776]

Absolutely YES. An 8S pack... 8 cells (or parallel groups of cells) require 9 balance leads. Whether a BMS or smart charger. Must be a miscount.

[flagman1776]

The TravelScoot original 10 ah LI battery with the BMS board & dumb charger... the LiFePO4 as built with BMS & dumb charger... required OVERNIGHT (8 hours) to charge. (Until the BMS failed.)
With the older lower powered Hyperion charger, I can still charge the same pack LiFePO4 pack (after rewiring) in 1:15 hours. The newer & more advanced PL8V2 should be faster still.

[grazy+1949]

Yep! Hands up guys there are 9 white leads and not 8 as I assumed. Where is the best place to buy the PL8v2 with fast delivery. I was told by another member to buy a power pack to accompany the Pl8v2. True or false? If true, what size power pack should I buy. This would be for my 55Ah LiFePo4. I'll use this on the flat, until I get my big mountain going battery pack sorted out (It will take me time to raise the cash.)

[Burgerman]

While you save, please read this thread as it will answer all the questions, and the ones you haven't thought of yet! viewtopic.php?f=2&t=1813

The PL8 will need a few 36 inch balance cable extensions and a FUIM3, and a power supply.

The power supply can be anything.
The PL8 is 1344 watts. Or 20 watts. You tell it.
So for max power you want a 50A and 24V supply. Such as a dual server supply made for us hobby people, or a quality bench power supply such as the two you see here http://www.wheelchairdriver.com/BM3-con ... arging.jpg
You can also use any 12 to 30V supply from say 5A to 50A or above. Such as the ebay cheap ones.

You will also likely want to make up a chair side charge cable, and a charger side charge cable such as this one here. That allows one simple connection, and plug and go... And its good for 40A charging. So your battery will be done in 1.5 hours from dead flat...
http://www.wheelchairdriver.com/BM3-con ... DCABLE.jpg

You will also need a means of watching battery voltage at the cell level, as you drive with that too small battery. So that you dont run a cell group too low and damage it. It will connect to the same balance cable. Theres hundreds of such things, heres one https://endless-sphere.com/forums/viewtopic.php?t=12815

[grazy+1949]

Hi Burgerman,

The above is an invaluable reply . Many thanks for your time and effort. I will study it diligently and build /buy the necessary cables and get a good power supply.



grazy1949

[grazy+1949]

I am having a body made in Atlanta, in return for teaching the guy how to model Porsche body kits in CAD:

[martin007]

Do you live in Spain or Morocco?

That landscape looks very arid...

[Burgerman]

I am having a body made in Atlanta

So most likely US.

[martin007]

It looks like southern Spain.

[Burgerman]

You are correct. His IP address resolves as a Spanish dynamic IP so Spain. I could look up exactly where if it wasn't dynamic and changing. So that wouldn't be very precise.

[martin007]

This??

[grazy+1949]

Hi Guys

I live in Andalusia , Spain. In the foothills of the Sierras de Mijas. I teach Alias AutoStudio CAD modelling to students online all over the world, so I have contacts in all Transport Producing countries. I have a guy in Atlanta , Georgia, who is using my CAD modelled body panels to mill out moulds from hard plastic. He will make prove-out Panels and then ship those to me. Once they have been fitted and modified, he will make new molds from them and finally produce carbon fibre panels, which are extremely light.



grazy 1949

[martin007]

It looks like southern Spain.

[grazy+1949]

Hi All

I now have the PL8v2, Revolectrix 24v 50A PS and the cables and plugs, all purchased from Digikey . A big shout out to Abel in Romania for providing me with the links.
Next job is to open up the welded alloy casing of the LiFePo4 55Ah pack which came with a second hand Electrokart golf buggy. It is not designed to be worked on, as the pack is glued into a welded up case with double sided tape (The top IS removable). Next I'll be able to see how the pack is wired and start working out how to make the necessary leads up, to enable me to charge and analyse it. I feel very much out of my depth, so I'll be asking questions. I am studying the PL8v2 online manual at the moment.
I hope to use this pack in my spare buggy in town, where the terrain is flat. I will be ordering a 24v 240Ah pack as soon, as I have the dosh. I am also looking for BLDC angle drive 25:1 or even 40:1 reduction motors (I'll be happy with a top speed of 12 mph to 15 mph 19-24 k/ph). They will have to be powerful enough to get a gross weight of 240 lbs up a 6 km climb, which includes a lot of 20% and 30% inclines. As far as I am able to deduce, this level of climbing performance has never been achieved and I don't know if even a LiFePo4 pack of 24v 240Ah optimally charged will be enough.
I have a BLDC powerchair, which has 24v 120w motors and a tiny lead acid 24v 12Ah battery and that can do a 6 Km round trip taking in 1 x 25% 150m long climb. So I am hoping that 6 X the BLDC power and 20 x the battery Ah LA v LiFePo4, will be enough to give me sustainable performance.
BLDC angle drive reduction motors:
If anybody has a good link for motors, with the full tech. spec. please let me have it. I have looked on http://www.taobao.com/ but I am unable to either find what I want or understand it, as it is about 90% in Chinese.

Enjoy your rolling
Grazy

[Burgerman]

Looking good.

[grazy+1949]

After several hours work with rubbish Asian import soldering irons, solder and flux. [ We bought the from a specialist Audi repair shop and the 2 soldering irons, mini blow torch for heating the big soldering iron ] .My son and me managed to solder the 11 cables to the D-Sub plug pair and test the with a multi meter. Today we'll do a Cellpro PL8v2 balance charge linked to the pc.

[Burgerman]

You may like to waste 20 mins reading these posts carefully. viewtopic.php?f=2&t=8521