Lawnmower batteries for ebikes?

Batteries, Chargers, and Battery Management Systems.
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AstroKat   100 W

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Lawnmower batteries for ebikes?

Post by AstroKat » Jan 10 2017 5:23pm

Starting a new topic... so as not to hijack others too much... :oops:

I'm wondering if Li-Ion replacement batteries for consumer mowers, blowers, trimmers, et al, are suitable for low-end ebikes? It seems that 48v 4ah Li-Ion batteries can be purchased for around $100, or less, from large hardware outlets like Home Depot.

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Ykick   100 GW

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Re: Lawnmower batteries for ebikes?

Post by Ykick » Jan 10 2017 5:38pm

I've got one of the 4Ah EGO packs. The stock charger is HUGE but they can be charged through the output port using other chargers. Connections can be kinda skanky since it's all proprietary plastic hardware. Search in my posts "lawn" "tool" "packs" and there's probably more detail that I'm unable to dig into right now.

I pulled about 3.7Ah from the pack. Pretty decent C Rate. They're 14S voltage so 58.8 is the top charge.
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AstroKat   100 W

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Re: Lawnmower batteries for ebikes?

Post by AstroKat » Jan 10 2017 6:17pm

Yeah, it could be more work to access the connectors than to build a new battery... :roll:

Where I'm going with this is that I have just received my replacement ebike kit from Amazon (48v 1000w, supplied by AW). It's almost exactly the same as the first one, except that the supplied bungee cord is red with green stripes and the original was green with red stripes. They must not waste any yarn in that manufacturing facility!

The entire kit was just over $200, so it's hard to justify several hundreds of dollars for a compatible battery. If the kit included a battery and was $1,000 then I would not be trying to build it, nor posting here... :D

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Re: Lawnmower batteries for ebikes?

Post by mark5 » Jan 10 2017 6:39pm

Links to people's posts on using lawn tool batteries:

charlie hepler's Ego 56V Bafang BBS02 Electra Townie
viewtopic.php?f=3&t=83525&p=1260714#p1260714

dephrag's build using EGO 56v
viewtopic.php?f=3&t=83525

mman1506's Echo 58V 3D-printed connectors
viewtopic.php?f=14&t=68750&start=50#p1192459

nutspecial's Echo 58V using 3/8" battery terminal connectors
viewtopic.php?f=14&t=68750&start=50#p1231438

Karl Gesslein: Use Your Cordless Power Tool Batteries To Power Your Ebike : What Could Possibly Go Wrong?
https://electricbike-blog.com/2016/04/1 ... -go-wrong/

DiseasesFromMonkees built a GreenWorks-powered bike
https://www.reddit.com/r/ebikes/comment ... l/d1nuxou/

maydaverave built an Echo-powered bike
viewtopic.php?f=14&t=68750&start=25#p1076299
viewtopic.php?f=3&t=72363&p=1092428#p1092428

ggtronics' video: Greenworks 40V 4Ah used between several bikes
viewtopic.php?f=14&t=55790&p=1123931#p1123931
https://vimeo.com/146953672

bluovalguy using GreenWorks + Ryobi packs for 15s 8Ah
viewtopic.php?f=2&t=59345

GMRedline's Merax Finiss w/ Luna Cylce Ebike Hub Motor w/ Craftsman 40v
uses 2 paralleled Craftsman/Greenworks 40V 2Ah or 4Ah batteries
viewtopic.php?f=3&t=87892

ngant17's Bafang BBS02, DROK and 60 volts
60V 4Ah Greenworks Pro ‘lawnmower’ battery & adjustable step-down converter
viewtopic.php?f=2&t=92793

DaveG using Greenworks 40V 5.0 Ah packs
viewtopic.php?f=14&t=93154&p=1378666#p1378666

SeakYourOwnLevel's 40v Ryobi e-Bike
viewtopic.php?f=3&t=94689
Last edited by mark5 on Apr 26 2017 5:49pm, edited 5 times in total.

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AstroKat   100 W

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Re: Lawnmower batteries for ebikes?

Post by AstroKat » Jan 10 2017 6:52pm

Thank you! Was this a list from another post or a sticky? If so, sorry to make you post it again...

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Re: Lawnmower batteries for ebikes?

Post by mark5 » Jan 10 2017 7:01pm

They're just bookmarked links, that I collect, to other people's work.

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AstroKat   100 W

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Re: Lawnmower batteries for ebikes?

Post by AstroKat » Jan 10 2017 7:11pm

Got it!

I try to look for relevant posts on forums before asking what might be a really stupid question but it doesn't always work out that way...

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spinningmagnets   100 GW

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Re: Lawnmower batteries for ebikes?

Post by spinningmagnets » Jan 10 2017 7:40pm

I also have an EGO 56V (labeled) string trimmer/weed wacker (verified 14S). Very happy with it. The Echo brand 58V cordless power tools are also verified to be 14S.

The Snapper brand 60V tools are 15S.

The DeWalt 20V/60V "Flexvolt" packs have 15 cells. Depending on the DeWalt interface that you plug it into, it auto-configures as either 5S/3P (typically called 18V), or 15S/1P to run the more powerful tools in their lineup.

15S voltage is 3.6V X 15S = 54V nominal, and when fully charged it is 4.2V X 15S = 63V

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AstroKat   100 W

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Re: Lawnmower batteries for ebikes?

Post by AstroKat » Jan 10 2017 7:52pm

Thank you @spinningmagnets! I read some of your articles on other sites before I landed here.

I only just unboxed the replacement motor and mounted it. I'll try it with the SLA batteries and report back...

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Sunder   100 MW

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Re: Lawnmower batteries for ebikes?

Post by Sunder » Jan 10 2017 8:18pm

spinningmagnets wrote: The DeWalt 20V/60V "Flexvolt" packs have 15 cells. Depending on the DeWalt interface that you plug it into, it auto-configures as either 5S/3P (typically called 18V), or 15S/1P to run the more powerful tools in their lineup.
If someone can please make one of these with a large number of cells that has a high number of factors (say 144) So that I can have anything from driving my car (72S2P) motorcycle (36S4P) eBike (12S12P) to my dad's farm inverter (6S24P), I will seriously be like:

Image
eBike: Q100H on 16S with Phaserunner FOC Controller
eMotorscooter: Vectrix VX-1 Died... Electrified Ninja in Progress!
eCar: Mitsubishi Outlander PHEV... Warramty expired. Still not game!
eHouse: 6.2kw On-grid solar with battery backup coming soon!

After 5 builds, the best advice I can give, is start with high quality products. I prefer http://www.ebikes.ca

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Re: Lawnmower batteries for ebikes?

Post by amberwolf » Jan 11 2017 4:08am

spinningmagnets wrote: The DeWalt 20V/60V "Flexvolt" packs have 15 cells. Depending on the DeWalt interface that you plug it into, it auto-configures as either 5S/3P (typically called 18V), or 15S/1P to run the more powerful tools in their lineup.

I expect this is done in the connector itself, as a set of interconnecting blades, kinda like how people have used plug sets on their RC packs for charge (parallel) or discharge (series/parallel) configurations. (I wonder if that's where DeWalt might've gotten the idea?)



Not completely relevant to the thread :oops: but sometimes we also use our ebike batteries to run our tools/mowers/etc. :)

(I have an experiment planned to happen next week to see if my B&D corded mower will run off my seriesed ebike packs, and for how long; I don't know if it's even a motor type that will run on DC, but we'll find out then. ;))

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Re: Lawnmower batteries for ebikes?

Post by craiggor » Jan 11 2017 5:09am

Here's my connector I made for my 36v4ah lawn mower battery using plastic kitchen choping board.ImageImageImage wooden prototypeImageImagethey just push on and lock in place like you would attach a battery to a tool.here is a simple one that has rubber bands to hold it in placeImagemore info on the pedelecs fourum small battery bargain thread.here is one made on a 3d printerImageImage
Last edited by craiggor on Jan 11 2017 5:11am, edited 1 time in total.

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Re: Lawnmower batteries for ebikes?

Post by dogman dan » Jan 11 2017 6:18am

That's a cool home made plug.

Back to the 1000w kit. I would suggest that 4 ah is not big enough to run a larger more powerful controller that comes with the 1000w kits,, It's likely 25 amps,, possibly even 30amps.

The mower battery,, at least in the form of one of them, more suitable for a tiny motor and controller,, under 15 amps.

Three in parallel would be 12 ah,, and should more able to run a larger motor/controller. But then it's 300 bucks.

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AstroKat   100 W

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Re: Lawnmower batteries for ebikes?

Post by AstroKat » Jan 11 2017 12:45pm

Very cool but wouldn't it have been easier to take the battery apart? :D

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Re: Lawnmower batteries for ebikes?

Post by craiggor » Jan 11 2017 2:35pm

Didn't want to void the 2 year guarantee. If they died I was going to take them back and say I only trimmed my neighbours bush a few times lol

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Re: Lawnmower batteries for ebikes?

Post by AstroKat » Jan 11 2017 2:41pm

:lol:

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Re: Lawnmower batteries for ebikes?

Post by 999zip999 » Jan 11 2017 5:10pm

Batteries are the expensive part of the build. Cheap dont last as money down the drain

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AstroKat   100 W

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Re: Lawnmower batteries for ebikes?

Post by AstroKat » Jan 11 2017 9:09pm

Sorry if this is a stupid question but what if the battery is a lower voltage (e.g. a 40v lawn mower battery with a 48v controller)? I know brushless motors will take a wide range of voltages but obviously you can't put a 48v battery on a 24v controller.

Will a 48v controller function at a lower voltage (even 36v or 24v) and what does it do? Does it supply the same amps at the lower voltage?

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Re: Lawnmower batteries for ebikes?

Post by Voltron » Jan 11 2017 9:28pm

Usually the controller will cut out from the lower voltage, thinking its protecting a 48v battery from getting drained too far. It might work with the right 36v controller ( most, but not all, 36v controllers will handle up to 60ish volts), esp if the battery has an internal BMS to cut it off at a safe discharge point so you don't kill the battery by accidentally running it down too far.
Last edited by Voltron on Jan 11 2017 9:31pm, edited 1 time in total.

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Re: Lawnmower batteries for ebikes?

Post by spinningmagnets » Jan 11 2017 9:31pm

Most electrical devices have a Low Voltage Cutoff (LVC), and that protects the battery pack from being drained down so low that it is damaged. A fully charged 48V battery has enough voltage that it can likely run a 52V component, but it will only run a short time. Once it drains down just a little, it will hit the 52V LVC, even though it still has plenty of 48V range left in it.

ha ha, we were both typing the same answer at the same time.

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Re: Lawnmower batteries for ebikes?

Post by AstroKat » Jan 11 2017 10:13pm

Yep, you guys are right. I just tested it by taking one of my 12v batteries out of series to drop our 48v kit down to 36v and nothing. I even reprogrammed the LCD to tell it the battery was 36v and still nothing.

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AstroKat   100 W

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Re: Lawnmower batteries for ebikes?

Post by AstroKat » Jan 11 2017 11:21pm

I see 36v/48v controllers that look VERY similar to what came in the kit: https://smile.amazon.com/Brushless-Cont ... B01N955I2G

I wonder if the controller is switchable inside? How would it know, otherwise?

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Re: Lawnmower batteries for ebikes?

Post by Voltron » Jan 11 2017 11:50pm

On some of the newer ones it can sense the input voltage and self adjust, and some have an external switch. Older ones required resoldering a jumper inside, or weren't switchable at all. That one requires the optional display to do the regen, might be worth checking if its required for switching the voltage too or if it auto selects.

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AstroKat   100 W

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Re: Lawnmower batteries for ebikes?

Post by AstroKat » Jan 11 2017 11:56pm

OK, good to know, thanks! This is an experiment and all good fun (until someone loses an eye, as my mother would say)... :roll:

There are no external switches but I''ll take it apart and check for jumpers, etc. Although, the supplied LCD didn't even come with a manual so I'm not confident of finding the correct jumper.

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Re: Lawnmower batteries for ebikes?

Post by AstroKat » Jan 12 2017 12:57am

Here's a pic from my phone of the controller's board. No obvious switches or jumpers...
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