Using 4 Milwaukee 9ah (162wh) Batteries to power Ebike?

[Krishna Kirtan]

Hello Guys,

I scored a deal on them batteries about $60 each. I wanted to keep the batteries as they are, since I have Milwaukee tools and the batteries have on board BMS.

My controller is a 36 volt controller, picture below.

Battery specs:
18 volts (fully charged they sit around 21 volts)
9Ah
162Wh
lg hg2 3000 mah 20amp discharge 15 cells.

Should I run two packs or all four packs? And any ideas on the range I will be getting?
Which way would be best to hook them up (series or parallel) ? I would be using the Milwaukee battery charger and the BMS inside the battery pack. I have a 3 year warranty on the battery..

link to my bike:

 

[D8ve]

It's impossible to tell your range. We get between 12 and 100 miles on 36 volt 16ah here. It depends on how you use the bike.
On 20+mph mtbs ridden hard with lots of hills the batteries have a very short range. On an efficient bike with a low speed ramp down and lots of effort from the cyclist the range can be high. Add in wind,water and tyre pressure then range changes again. Oh your weight and health also count.
Our uk rule of thumb is about 3 miles per ah at 36 volts.

 

[anotherkiwi]

Should I run two packs or all four packs? And any ideas on the range I will be getting?
Which way would be best to hook them up (series or parallel) ? I would be using the Milwaukee battery charger and the BMS inside the battery pack. I have a 3 year warranty on the battery..

Yes I would parallel 2 then series the pairs for a 36 V 18 Ah battery. Me on my bike would get about 96 km range tops from that setup. You will get different range because your riding style and bike are different.

 

[Krishna Kirtan]

Does someone have a diagram for two parallel and two in series?

 

[anotherkiwi]

https://www.google.fr/search?q=parallel+series+battery+connections&espv=2&biw=1130&bih=915&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjUh92N8KXSAhVHOxQKHdtGCxYQ_AUIBigB

 

[Deleted member 4366]

The motor looks like a MXUS standard Chinese 250w motor. We need the code on the side of it to identify the maker; however, it doesn't make a lot of difference because several companies cloned it. Some of the old ones didn't have a clutch. Check whether the wheel spins freely by hand in the forward direction compared with backwards. Without a clutch, there's no difference. With a clutch, you should see a big difference.

The thing on the handlebars is the receiver for a cycle computer. It's useless without the missing removable part, so take it off and chuck it. There's a sensor on the fork, which you can remove as well. If you want to know how fast/far you go, you can buy a new one from Ebay for about $5.

I can't see where those two wires go to. I would guess that they're for a front light. You need to measure the voltage when everything is switched on.

That motor with its 16 amp controller will give you about 20 mph if you help it by pedalling. They're not meant to be used on their own like a motorcycle. Don't let it go too slow up a hill. It needs to be kept above 8 mph to stop it from burning out.

Range with two of those batteries would be about 15 to 30 miles depending on your weight, hills and how hard you pedal.

I would use just two of those batteries in series to save weight. If you want to bring two into a parallel connection, it's very important to make sure that they're at the same voltage when you connect them together. You must completely separate all batteries when you charge them.

If you just use to in series, join one positive to one negative and use the remaining positive and negative to power the bike. Be aware that if you connect to the controller the wrong way round, it'll instantly blow. You'll get a bit of a spark when you connect the correct way. don't let that frighten you.This is how to wire them up if you want two in parallel and two in series. Ignore the thin black wires, just look at the thick red and black wires.

 

[Krishna Kirtan]

Each battery is about 2.5 lbs,
if I run just run two batteries it seems it might still be better then my current battery?

Any ideas where can I find an extra battery case to fit the two Milwaukee battery?

The one I have is falling apart..and I don't wanna ruin it.

 

[craiggor]

I use two 36 4ah for short journey's and carry more for longer ones.

 

[Krishna Kirtan]

Right now I am using two in series. 36 volts and can anyone tell me the Ah for the total pack? or how to calculate it.

 

[craiggor]

9ah.

 

[Danidl]

Right now I am using two in series. 36 volts and can anyone tell me the Ah for the total pack? or how to calculate it.

... When you put two or more batteries in series .. head to toe then the total voltage accross the combo is the sum of the voltages from each of the batteries. The total amount hours is the amp hours of the least capacity battery.

... When you put two or more batteries in parallel, .... the heads joined together and all the tails joined together, the total voltage is the voltage of the least power battery but the total amount hours is the sum of all the individual batteries.

 

[Krishna Kirtan]

The motor looks like a MXUS standard Chinese 250w motor. We need the code on the side of it to identify the maker; however, it doesn't make a lot of difference because several companies cloned it. Some of the old ones didn't have a clutch. Check whether the wheel spins freely by hand in the forward direction compared with backwards. Without a clutch, there's no difference. With a clutch, you should see a big difference.

The thing on the handlebars is the receiver for a cycle computer. It's useless without the missing removable part, so take it off and chuck it. There's a sensor on the fork, which you can remove as well. If you want to know how fast/far you go, you can buy a new one from Ebay for about $5.

I can't see where those two wires go to. I would guess that they're for a front light. You need to measure the voltage when everything is switched on.

That motor with its 16 amp controller will give you about 20 mph if you help it by pedalling. They're not meant to be used on their own like a motorcycle. Don't let it go too slow up a hill. It needs to be kept above 8 mph to stop it from burning out.

Range with two of those batteries would be about 15 to 30 miles depending on your weight, hills and how hard you pedal.

I would use just two of those batteries in series to save weight. If you want to bring two into a parallel connection, it's very important to make sure that they're at the same voltage when you connect them together. You must completely separate all batteries when you charge them.

If you just use to in series, join one positive to one negative and use the remaining positive and negative to power the bike. Be aware that if you connect to the controller the wrong way round, it'll instantly blow. You'll get a bit of a spark when you connect the correct way. don't let that frighten you.This is how to wire them up if you want two in parallel and two in series. Ignore the thin black wires, just look at the thick red and black wires.

That picture looks confusing. Does anyone have a YouTube video ?

 

[anotherkiwi]

https://www.google.fr/search?q=parallel+series+battery+connections&espv=2&biw=1130&bih=915&tbm=vid&source=lnms&sa=X&ved=0ahUKEwjHi5CitK3SAhXEuRQKHWIzCEkQ_AUICigD&dpr=1

 

[Krishna Kirtan]

https://www.google.fr/search?q=parallel+series+battery+connections&espv=2&biw=1130&bih=915&tbm=vid&source=lnms&sa=X&ved=0ahUKEwjHi5CitK3SAhXEuRQKHWIzCEkQ_AUICigD&dpr=1

Thank you. Doing a parallel series will yield me what battery size and volts? How many watt hours and AH?

 

[Danidl]

Thank you. Doing a parallel series will yield me what battery size and volts? How many watt hours and AH?

Let's say you had 4 batteries each exactly 18v and with capacity of 4, 2,5, 8 amp hrs.
Connect them all in series total voltage end to end 18 x4 =72v total capacity 2 amp hours. .. the fact that there is plenty of charge in the remaining batteries is irrelevant. Once the lowest capacity one is discharged, there is no path for the others to drive current.
If you wanted 36 V , best case would be to connect the 2 amp in parallel with the 8 amp and the 4 amp in parallel with the 5 amp and that would give a 36 V 9 amp hr pack. That there was 1 amp hr remaining in one segemnt is irrelevant.

Connect them all in parallel
Total voltage 18v total capacity 19amp hrs.

Say your 4 batteries were not exactly equal in voltage eg 18 and 17 volts but the same capacities as above.and you wanted a battery pack giving 35 to 36 V.
Join the two 17v batteries in parallel , join the two 18v batteries in parallel and then join both packs in series.
Your total voltage is 35 and the capacity will be either 9 amp hr best case or 6 amp hr worst case.
Warning But you cannot connect the 17 V and 18 V batteries in parallel. A very large current will flow from the 18v battery trying to charge the 17 volt battery , and could damage both.

Your watt hrs is voltage x AmpHrs

 

[anotherkiwi]

See my post #3 above.

Parallel connection of 2 x 18 V 9 Ah packs = 18 V 18 Ah
Series connect the two paralleled groups for 2 x 18 V 18 Ah = 36 V 18 Ah

 

[Krishna Kirtan]

What would be the rating for: four batteries to in 2 parallel and 2 in series?

See my post #3 above.

Parallel connection of 2 x 18 V 9 Ah packs = 18 V 18 Ah
Series connect the two paralleled groups for 2 x 18 V 18 Ah = 36 V 18 Ah

 

[Danidl]

What would be the rating for: four batteries to in 2 parallel and 2 in series?

.Read the posts, we have given you enough information,