BarnBoy’s 24V EVG Battery Improvement Project…

[BarnBoy]

Hey kauaikit, watching yours and BB posts , getting ready to swap out batteries on original 24v model / controller . Chatted with BB thru this site yesterday but as it all seems to come back around to you I thought I'd reach out. To clarify
1. 2 x 7s5p will fit (maybe some slight modification to Battery box). these ? wouldnt they give me 32Ah??

laudation 24V16ah electric bicycle battery 24V battery 7S 5P Built-in 25A bms​

Anything else I need to consider .
thanks in advance Mike
2. original charger will handle charging ,(they come with a charger anyway). you mention adjusting it to 29.2 is that the 2 little white screws?? How do you know how much to turn?
3. I dont need to install diodes or anything complicated (for me)

Directly connecting two packs in parallel is not recommended; use diodes to isolate the packs (two BMS’ conflicting each other!!!). If you don’t use diodes, the packs will not last. Common Cathode Diode will cost $25 on DigiKey…

Yes two 16Ahr packs will get you 32Ahr….

And yes, x2 7s5p packs will fit with plenary of spare room. Box mods are not needed. I just added holes for the charge ports and two Drok battery meters….
-BB

@Rome - this vintage 1999 bike is 26 x 1.95….

 

[sbaussie]

Directly connecting two packs in parallel is not recommended; use diodes to isolate the packs (two BMS’ conflicting each other!!!). If you don’t use diodes, the packs will not last. Common Cathode Diode will cost $25 on DigiKey…

Yes two 16Ahr packs will get you 32Ahr….

And yes, x2 7s5p packs will fit with plenary of spare room. Box mods are not needed. I just added holes for the charge ports and two Drok battery meters….
-BB

@Rome - this vintage 1999 bike is 26 x 1.95….

Thanks BB. So I put it all back together with the 12V 15Ah SLA's I bought when I first got it. Fully charged reads 28.2 V . Wouldn't run so opened it up and one of the wires from controller to rear hub (2 small gauge black wires) was broken . So soldered it all back together and off we went . Light on controls goes from green to orange whilst riding and there is a 4 chirp alarm / tone. Got me home and I put it on the bike stand to check it out . Battery still have 26.8 v Once I start motor (on stand) it runs fine but quite quickly switched to orange (medium) on battery meter on controls and gives the 4 chips alarm . If I stop the light goes back to green . Runs about minute to minute half gives 4 chirp and a quicker chirp and shuts down . Hub is warm to touch not hot (can easily keep your hand on it ). If I wait 5 minutes or so starts and runs but goes thru same sequence for minute half then stops again.
Any Ideas? thoughts ?. Hub is noisy but as I have never had one before not sure if that is normal? Once you shut off power from thumb throttle wheel continues to run smoothly for a while so bearings seem to be fine .

 

[BarnBoy]

Wires to the motor are: POWER and THERMAL. From the above, it sounds like the thermal switch may be tripping. Can test this by just shorting the controller side of the interface. Make sure your repair is protected. My SLA batteries would transition from GRN to YEL in a few miles and then sit in yellow until the battery dropped to red. With the 7s packs, I don’t see the red zone the Laudation packs don’t go below the 20/18 V (approx) red and shutoff points…

with that massive hub, the brushes may be getting hot, trip the thermal switch, but you can’t feel the heat. Possibly why it resets so fast too….

did I post the EVG schematic???

guesses only!
-BB

 

[sbaussie]

BB, power leads Ok and pretty obvious but those tiny little leads for thermal switch really are a pain as I need to find a small connector so at this point they are soldered/ Safe to assume the Thermal switch wires could be swapped and it would not make a difference. ie no +ve -ve as last owner had just cut them at some point to remove rear wheel I assume. (little connector in that plastic case was gone and they were just twisted and taped?) .

 

[BarnBoy]

Yes, no polarity for the thermal switch required. But having the thermal switch is a good option to prevent the motor from smoking....

Use Ohm meter to verify the thermal switch....

But for a short test, you can check if that is the issue by shorting the connection (controller side) at the wheel splice area, Any small male/female connector will work....

Do you need the schematic?? There may be some other controller issue involved here. IDK...
-BB

 

[sbaussie]

BB found the schematic online, >Yes I see it is just a circuit so leads don't matter .I pulled hub apart to check it all out .I will run a little beefier wire (18 so i can use connectors I have around ,Hard to find 24 Gauge quick connects. On one of the magnets what looks like chrome covering is torn .Doesn't affect magnetism but wonder if it is something I should address/ clean up .I believe there is a gap between the magnets and the windings so don't imagine they touch. I checked continuity while I heated with a heat gun was pretty freaking hot before thermal switch closed . will update

Mike

 

[BarnBoy]

I also have a copy of the full service manual. There is a section of Morris Error Codes that might help you with the beeps and this cause….
-BB

 

[sbaussie]

I also have a copy of the full service manual. There is a section of Morris Error Codes that might help you with the beeps and this cause….
-BB

Update , the rear hub motor was making some funny noises so I swapped out rear wheel for a 48V 750 Watt Chinese built wheel. (major truing required) I made a plate and mounted to frame to mount 48V LiPo4 battery to so it all fits inside housing etc and looks original except for the LED display (speed ,distance . PAS . Odometer) WOW what a difference there are 5 setting for PAS , on number 5 the bike goes 30-35mph . Obviously pedaling does nothing with standard gearing at that speed , just looks like you are pumping !! Will swap out front chainring . first run went 24 miles and display still said 60%
charge left . Ill run it out completely this coming weekend and ride home under human power if needed to see what it will put out mileage wise.

Mike

 

[BarnBoy]

Well done Mike!
-BB