18V cordless tool battery packs, brand for most value Ah/$

Hello

So I've been inspired by some of the builds in here(https://endless-sphere.com/forums/viewtopic.php?f=28&t=84905&p=1273587#p1273587) that have some neat solutions to using a standard battery pack from a cordless tool to power an e-bike.


So apart from how to design it the question that comes to mind in the jungel of battery/cordless tools brands are: what make/brand do you think gives the best value for money Ah/$? It's kind of easy just to calculate the price pr Ah, but with no previous experience of how fast the different brands discharge/hold up it's not so easy to conclude.

If you look at this test for reel life use of 18V battery drills(Sorry it's in Norwegian, but still I think most people would understand, do to the numbers alone, just scroll a bit down) you'l see that Milwaukee can drill almost 3 times more(52 against 20) 30 mm hulls than Makita on one battery. Make you wonder if they got a faulty battery from Makita? https://www.tv2.no/a/9134858/

Searching on E bay I find:
- a 2 pack MILWAUKEE-EXTENDED-HIGH-CAPACITY-M18-18V-RED-LITHIUM-5-0-AH priced at $94.88
https://www.ebay.com/itm/2-MILWAUKEE-EXTENDED-HIGH-CAPACITY-M18-18V-RED-LITHIUM-5-0-AH-BATTERY-BATTERIES/292663425264?hash=item44241978f0%3Ag%3AirQAAOSwrU1bEuFG&_sacat=0&_nkw=Milwaukee+M18B5+18v+5.0Ah&_from=R40&rt=nc&_trksid=m570.l1313#shpCntId

- a 2 pack Makita BL1850B 18V LXT Lithium-Ion Batteries 5.0Ah at $89.00
https://www.ebay.com/itm/2-Genuine-Makita-BL1850B-18V-LXT-Lithium-Ion-Batteries-5-0Ah-BL1850B-21/302826079225?hash=item4681d743f9%3Ag%3AA7cAAOSwpG1bYB5W&_sop=15&_nkw=Makita+bl+1850B&_sacat=122840&_from=R40&rt=nc&LH_TitleDesc=0%7C0

Thank you!

Terje

It best to look at mower battery that are what voltage you need. 48v or 56v. And it's always best to have one whole complete battery instead of a lot of little ones. For longer life.

Thanks

Problem is that I have none experience with this line of batteries, but I'l look into it, any brand in particularly? What would the form factor of those be?

Terje

999zip999 said:

It best to look at mower battery that are what voltage you need. 48v or 56v. And it's always best to have one whole complete battery instead of a lot of little ones. For longer life.

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Unless you want to travel and take your bike and batteries on an aircraft !

Nemo hey my brother just left two weeks ago went back to Norway Homestead he lives above the Arctic Circle he says it's 88 degrees and Norway is sold out of fans. Can you confirm this.

Ha ha, yes something like that, usually we have like 40 Fahrenheit, but not this summer no.

I live in Oslo by the way, about 200 km south of your brothers place.

So I did some googling last night and found some interesting reading and a link for a BATTERY MOUNT & CABLE KIT for the Ego, they are sold out at the moment, but list that there vill be more in August. Voltage isn’t everything is talking abouth all the different versions of the Milwaukee M18 High Output Cordless Power Tool. Using cordless tool batteries for an e-bike discuss the idea of using cordless tool batteries to power an e-bike.

BATTERY MOUNT & CABLE KIT: https://land-surf.com/products/ranger%E2%84%A2-battery-mount


Voltage isn’t everything: https://toolguyd.com/milwaukee-m18-high-output-cordless-power-tool-tech/

Using cordless tool batteries for an e-bike: https://www.electricbike.com/cordless-tool-batteries-for-ebike/

Terje

I'm using Bosch bat838 36v@4A, also Bosch bat620 18v@4A. Sometimes the 18v bosch bat620 are on sale and with 2 you can series them 36v@4A. Here we don't have Bosch 36v@6A.
I been using Bosch Fat Packs for several years with good luck.
I'm curious to see how the new Bosch Core 18v pack hold up.

Bosch now have 18v pack in 8 and 12 Ah capacities, 5s, 3p, of the new 21700 cells.
But the cost is likely to be very high.
https://toolcraze.net/bosch-procore-18v-batteries-now-include-12-0-8-0-4-0-ah-batteries/
I wonder how long before they have 12Ah in the 36v size...they already have 6Ah.
http://www.bosch-pt.com.au/au/en/battery-pack-gba-36v-6-0-ah-209604-1600a00l1m.html

Amazon .ca has 2x GSX- 18v@6.3A Bosch Core batteries plus 18v charger with built in cooling fans for 220.00 cdn, about 165.00 us

So I have a question, whats keeping the batteries for discharging to fast if one only make a simple battery-mount that only tap into the plus and negative leads?

Are there brands that are better equipped/suited to handle this(I guess the tools them-self usually handle this, not the bms in the battery)?

I parallel my packs together to get maximum power . also this causes less stress on your battery . Using only 1 battery at a time would not be a good idea and would shorten your battery lifespan

Another thing to look at is battery cooling. Tool batteries are not all designed to handle the sustained power load of an ebike, and some get very hot if you draw much power from them for a period of time. Operated in that fashion they won't last very well.

I have a variety of tool batteries and have looked at more, and I selected the EGO batteries due to their cooling design. They are also the most compatible voltage for common ebike motor controllers with 14 cells in series, which some vendors call 52V while others 50V and EGO mentions 56V.

The 18V tool batteries are 5 cells in series which isn't a very good fit. Series connecting two packs makes 10S which is a bit low at 36V but has various problems that can lead to early pack failure if there's no BMS to shut off the system when one pack goes out before the other.

bionx 1954 said:

I parallel my packs together to get maximum power . also this causes less stress on your battery . Using only 1 battery at a time would not be a good idea and would shorten your battery lifespan

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Any problems paralleling the packs without paralleling the cells? I often debate with myself if I should add a balance connector.

ga2500ev

I have only used Bosch 18/36 v packs. I leave them unopened and use sheet metal folded over to get a nice tight connection on the slide in terminals then wire them to each other to get 36v packs. I then series the 36v packs to get 72v. I had good success doing this and had no problems so far. For charging I unplug the series harness and charge at 36v.. Another reason not to modify the packs is that the Bosch packs have a 2 year warranty .

This certainly is not as easy as thought it would be, I was more or less committed to two or tree 18V Milwaukee 5A.
Ego is seriously expensive here in Norway: EGO 7.5Amp 56V $445 and 5.0Amp $328. Compered to Milwaukee 18V 5A that sells for about $60 each.

Bionx 1954: do you have a photo of your setup, including the folded sheet metal? So you are using 4 batteries in total?

If you are looking to have a 36 v system you would need pairs of 18v packs. So 4 X18v@5A would give a 36v@10A battery. You could then use a 36v charger to charge, or unplug the series harness and use a 18v charger. I use thin strips of metal about 1/4 in wide and fold over until it thick enough to slide into the battery terminal slot tightly with some metal extended out to use a terminal on then cover the exposed metal with tape to prevent shorts

So what is it to be used for ? Motor , controller combo. Do you have hils. Weigh yous as well as cago. Range. This will tell you the size of batteries you need.

With them 5 cans in Series 18V tool packs, either 36V or 54V setup, with a corresponding Low Voltage Cutoff done by the controller.
I am going from 48V to 36V for ease of pack building 10S, rather 13S. My top speed is decreased from 46kph to 37kph, which is my cruising speed anyways, and I dont need 46kph speed. Plus smaller pack, more easily hidden away.

I priced tool pack batteries at $60/Ah thats cdn so $48usd/Ah.
Reputable ebike companies are $40/Ah cdn but they use correct shipping methods which adds cost.

Going to Home Depot and buying packs is easy and a breeze and easy returns if you dont hack up the pack.
Also you going to buy the packs charger or use your own?

Yes motor and controller, and do we have hills, Oslo have about 600 meter terrain up from sea level. I live at maybe 100 moh and work in the city centum at sea level. Noting to carry, only me at 80 kg. We also need to have pedal assist for the bike to be legal, and max 25 km/h.

Yes the ease of buying packs is a good selling point for me, plus I'm not going to hack any packs, I'm not that skilled in electronic. No I was thinking of using the standard double charger, just take the packs out and charge. Seen in conjunction with the max 25 km/h limit in Norway, maybe 36V would be good?

Need to compare watt hours per dollar to account for voltage differences.

Recently EGO had 7.5AH 56V packs for $250 US. 14S is 51.8V at 3.7V nominal, so 7.5AH is 389 watt hours, or $0.643 per watt hour.

Compare to Milwaukee 18V 5AH at $60 which would be 18.5V * 5AH or 92.5 watt hours, this would be $0.649 per watt hour.

Yes correct, this was the starting point of my tread, so the price seems fairly equal, except that good a price on the Ego is hard to find here.

The cost for buying Ego in the US would be: $250 + shipping $50 + import duty 25%= 375 $. That would give a $0.964 per watt hour at the best.

Sale pricing is unstable, changes over time are dramatic. Handling a bunch of small packs has costs of its own. There are a number of 14S tool packs, EGO isn't the only one (though it might have the best thermal design).

How about one big battery the size you need from China . Or from Paul at em3ev. Great quality good service department and he test his product. Still what motor combo middrive or geared or direct drive. A middrive is good for hills as it goes thru the drive train and it's gears. As I believe you don't need as a powerful battery as with you would use with a direct drive hub. Ect.

Thanks, looks like a very nice shop.

Wonder what shipping would be to Norway? Not decide on a drive yet, my first thought was to use a friction drive, but not so sure any more, rains a lot here in Norway, usually then, when we have normal summers!