Non EGO battery to power EGO Mower

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  • Updated 4 months ago
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I have an eBike battery (14s8p) 56V 15Ah 50Amp continuous BMS. Will I be able to power an EGO mower if I wire it to the + and - of the mower ? I am concerned about the 2 other pins T and D. Are they used at all while mowing ?
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Remi

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Posted 2 years ago

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Jacob

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Hehehehe. Only one of them is used. I think its D. Its what triggers the battery to display its current state. Soooo.... im like 90% sure you can.

Be careful of course.

Speaking of your bike battery..... what motor is it running?
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Remi

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It is the mid-drive cyclone 3000W kit. Pictures of the beast here
https://endless-sphere.com/forums/vie...
Thanks for the reply.
Am I the only one thinking about putting a different battery on those things ??
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Jacob

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Im backwards. I want to put ego batteries on everything.

Like this... contraption

https://youtu.be/XGkd7TBO2a4
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Jacob

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Or mow-aahahaahaahah
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David HD, Champion

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Blue Angel, Champion

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DUDE that thing looks incredible!!! It looks more like something to get rid of your neighbor's dog than to cut grass! Awesome!
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szwoopp, Champion

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That is awesome.  Nice work on getting it put together and running !
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Sid Parish

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I wouldn't do that if I were you I don't know if I'd be willing to take the chance it would tear up my mower
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Jacob

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So remy. I bet.. i bet that the blue wire is required. The blue wire connects to the controller board for all of the tools. I havent tried yet but i would bet money that it won't work.
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mastag

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Hello, so has anyone actually tried running a non-Ego battery in an Ego mower? I bought a used Ego mower without battery for cheap. It's got 3 terminals. I make my own e-bike batteries and could make a battery for cheaper than the $350 7.5Ahr Ego battery. But I'm concerned that the mower will not function with that D terminal (blue wire) unplugged. (Regardless, I'll try it out within a couple weeks and report back.) -Ryan
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Jacob

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You will lose ramp up on the motor. Get a simple pwm board on eBay and make sure it has ramp up control. That way your amp draw won't be a billion amps. Plus you can now control the rpm of the motor.

Also put in a circuit breaker or fuse that is accessible.
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mastag

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Jacob, thanks for your help.  In another thread, (https://community.egopowerplus.com/ego/topics/ego-20-mower-parts-all-parts) you said that a resistor (the white bar) may be for motor ramp up.  I didn't bypass that.  Do you know ... is this resistor or the ECM providing motor ramp up?  Also, there already appears to be a fuse installed on red wire near the battery.

Edit to add:  The wiring on my mower looks identical to the photos in the other thread, except there is a fuse on the red battery lead and that green donut (filter?) is not there.
(Edited)
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Jacob

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That resistor is actually to assist in braking the motor. When the bail handle is released, the motor POS and neg are connected together causing braking. The resistor makes it so it doesn't lock up hard
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mastag

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Jacob, got any recommendations for a pwm board? I don't know anything about those. Without one, my battery is going into protect mode when I try to start it. Probably due to the high starting amps of the motor you speak of.
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Jacob

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I use
https://www.basicmicro.com controllers. 60v . They are expensive however they have units with full PLCs in them.

Otherwise eBay. But all the cheap ones on ebay will fail you cuz they are junk. But they also aren't 220.00$ USD

https://rover.ebay.com/rover/0/0/0?mp...
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mastag

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I'll let you know if I run into any problems later, but my mower now seems to be working well with my custom battery.  It was a little bigger project than I was hoping, since I had to remove the stock ECU and replace it with a PWM motor speed controller.  I think this is a great project for someone who is already into making battery packs (and already has the battery making tools and battery cells).

Battery:
I built a 12.6Ahr battery pack (14S 4P = 56 li-ion 18650 cells at 3.15 Ahr each).  I mowed my entire small yard for about 30 mins through some thick grass and the battery voltage only dropped from 58V to 53V!  The battery cost about $200 to make (but like I said before, I was trying to find a use for extra new battery cells that I already had, so my added cost for this project was minimal.  It probably doesn't make financial sense for others to make a pack from new cells.  The people who pillage used battery cells from old laptop batteries or cordless tools could do this project for pretty cheap probably.)  I won't go into battery making right now. If interested, watch some videos online about how to make e-bike battery packs.  Here is the BMS I use for 14S packs (14S 30A BMS) https://www.aliexpress.com/item/Free-Shipping-51-8V-lithium-ion-battery-bms-3-7V-14S-30A-BMS-with-th... 

Mower:
My mower is the cheaper EGO 20" push mower.  It has a brushed motor.  I think this is probably the best candidate for using a custom battery.  I hear that the more expensive steel deck mowers have brushless motors (requiring a different motor controller) and are self-propelled, which may be more complicated to convert to a custom battery, unless that mower ECU allows the use of a custom battery.

Charger:
I'm using my 52V (14S) e-bike battery charger.  This is another cost savings for me since I already had it.  https://lunacycle.com/luna-charger-52v-advanced-300w-ebike-charger/  

Here are the parts I used:
PWM motor speed controller (12V-80V, 30A) https://www.ebay.com/itm/12V-80V-30A-Digital-Modulator-PWM-DC-Motor-Speed-Controller-24V-36V-48V-72V...
Push Button Circuit Breaker (30A) https://www.ebay.com/itm/DC-50V-Push-Button-Resettable-Reset-Thermal-Circuit-Breaker-Panel-Mount-5A-...
DC-DC Converter (15V-58V to 12V) https://www.ebay.com/itm/DC-DC-Converter-Module-Buck-Voltage-Step-down-Power-Supply-15V-58V-to-12V-M...
Voltage Display (5-120V) https://www.ebay.com/itm/1x-Mini-DC-5-120V-Voltage-Volt-Meter-Voltmeter-Blue-LED-Panel-3-Digital-Dis...
Illuminated push button switch https://www.aliexpress.com/item/1Pcs-Waterproof-Metal-Push-Button-Switch-With-LED-light-3V-5V-6V-12V...

Here is what I did:
1. Remove the battery tray.  Then remove the mower body from the mower deck.  (Lots of screws underneath the mower).
2. Carve out a section of the battery tray (the connector terminal area) so I can fit my bigger rectangular shaped battery.
3. Remove the ECU of the the mower, since it only runs with EGO batteries.
4. Remove the EGO color LED and push button.  Replace with push button switch (for headlights), voltage meter, potentiometer for the motor speed controller, and a circuit breaker switch.
4. Rewire the mower and install all the new electrical components.  (See wiring diagram).  All relays in the handlebars were retained (except the one that cuts off the motor if the handlebars aren't extended), so the mower is started normally with the stock button and bale on the handlebars.
5. Reassemble mower.








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szwoopp, Champion

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Interesting - thanks for sharing
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mastag

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More pics of the battery: