Dual 48 volt battery setup

R4yD8R

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Greetings, I am in the process of setting up a dual 48 volt battery system on my DIY E-bike. I installed a conversion kit on a mtb I have about a year and a half ago and it's been decent for the most part but some of my commutes push the battery to it's limits and if I forget to put my battery on charge right away I don't make it home and either have to pedal which sucks worse than it did before I had the motor or jump on public transportation and on the way home is the worst time to have a dead battery. I just want to be home.

I already ordered 2 new batteries which are exactly the same as the one that came with the kit. They are 48 volt 13aH Hailong style. I was originally planning to get ones with more capacity such as 15 to 20 aH but they are significantly more costly and I found a deal that just could not n be passed up on the ones I got. They are regularly priced at $249 each. I saw a coupon for $30 thinking it would be only for the second one but when I checked out both batteries were $30. I couldn't believe it, my cart subtotal went from over $500 to $152 and change as I also had a couple of other things with the batteries.

Which brings me to the reason I am posting. I won't have the batteries until sometime between May 1 to May 7th so in the meantime I've been doing more research into the wiring. I have a decent grasp on most of it and I'm capable of doing the actual work involved because none of the batteries nor the controller have the common connections that the adapter has on it so I'll be doing some custom wiring work, which I more than likely would have anyway because I want to keep things neat and as tight to the bike as possible.

My confusion still lies with the balancing/equalizing of the batteries. The new ones are coming from the same supplier at the same time however I know that's no indication that they will be matched voltage wise. The adapter I bought is more than just a wire jumper, it has a device of some kind wired into the line between the 2 inputs and the output and it's called a dual battery pack discharge adapter however from what I can gather it sounds like I still might need another device to actually do the balancing!/equalizing. If anyone has any input on this, it would be greatly appreciated.

Dual Battery Pack Switch Balancer, 20V-72V Double Battery Discharge Converter Providing Lasting Power for Electric Bike https://a.co/d/fRoplEY

This is the device o bought a along with 3 of these...

DROK 48v Battery Meter, 10-100v Marine RV Battery Capacity Volt Monitor 12v 24v, Lithium Battery Voltage Fahrenheit Temp Indicator Gauge https://a.co/d/1EdhEbP

This is what I'm curious to know if I need as well?

LiTime 48V Battery Equalizer, Active Balancer for 24V/36V/48V Battery Bank, Supports for LiFePO4 Lithium Battery, Lead Acid, Gel, FLA, SLA Battery, Perfect for RV, Solar, Trolling Motor, Off Grid https://a.co/d/6rWWFS9
 
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It would be useful to see a pic of what you have. I don't have direct experience with dual batteries. From what I have come across on utube, they have only ever mentioned the first device posted. It draws current from both batteries, continuously drawing current from the battery with the higher voltage. Thats why it doesn't matter if one battery has a higher capacity, but the rated voltage for both batteries has to be the same.
 
1. Battery Blender : this allows both batteries to discharge safely in Parallel to power your bike. Parallel blending means both batteries discharge to/at same level. Please note for Charging - you need to charge each battery seprately - a Blender wortks Downstream (discharge) and does not Upstream (charging).

2. If you have correct Display set for 48V - it will show % battery based on 48V - since your blending - both batteries even - you do not need to add unecessary meters. Since the Display measure V post-controller - reading V at the battery itself is technically more accurate but difficult to correctly attached meter at the battery s
 
3. "Balancing Cells" in a "individual battery" is best left to be discussed with other experienced swimmers togther at the deep end of the pool. You are currently at the shallow end with your 1st eBike.
DO NOT ADD THAT BALANCER which is NOT designed for this type Lithium Ion battery. Lithium Phosphate is NOT our battery che
DO NOT buy/add a Fast Charger - charge each battery with a charger rated a Amp match by the battery supplier.
It is rarely possible to charge each battery to the exact same level (avoid charging to 100% - best to charge to 80%)
but that is what a Blender is for - it will discharge the Higherbattery until it matches the Lower then safely discharge from
both.
 
I did not buy the last item from my post. I have a controller and a balancer, that's all besides the 2 batteries. I tried it out but have a Comm issue so only throttle works, no PA and the display shows a code 30 and shuts down after a few minutes. Also the one day I used it to go to work the controller overheated on the way home but that's possibly because I installed it in a sealed plastic container with foam padding in order to mount it onto the bike. I took it off when I got home and put my single battery back on. I had to buy another one of Yose Power's junk integrated controllers for $50 until I can get this figured out.

The controller I got for the dual battery setup has the exact same interface as the Yose Power one that is in the base mount. I found the fault with them. The black and red power wires come off the pcb really close to the opening in the aluminum and plastic base mount and inside that case there's a ridge on the aluminum part that the wires can touch so after riding for a while the wires bounce off that shelf on the aluminum and this wears on the casing for the actual wires and when it has worn through the casing enough on both wires and they touch the aluminum at the same time it shorts and there's no fuse on the controller pcb so the current has free range to fry circuits at will.

I can't tell exactly what's getting cooked but it doesn't matter anyway because they pour some type of rubbery plastic resin or something into the base which totally covers the entire board immersing it and by the time I got to the point where the board would actually come out of the base it was pretty much destroyed physically so they aren't designed to be serviceable. I suppose if I had another one to try I could be more careful removing it but it would be a very tedious and time consuming job that isn't worth my $50 for a replacement.

So now I have a handle on what not to use, anyone have suggestions as to what I can use?
 

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as long as same voltage this is what I use and it works great


looks just like the one in the image
 
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This is the one I used!

Now I am alittle paranoid to have have both batteries turned on at the same time. So what I do is when one battery is low then I turn off the #1 battery and then I turn on the #2 battery. It works for me!

Here is how it's done!

I use a regular Black lamp cord and XT60 connectors. Then soldered the lamp cord to the XT60's then routed the cord and plugged in the XT60 Connectors. Makes for a clean and easy installation.

Side Note: I don't have a REVV1 Bike. I use this item on my Keteles K800 2000 watt dual motor ebikei
 
your combiner is only 30 Amps output you will choke your bike and lose all sort of power,
depending on how you wire them, series vs parallel, it could blow it, i dont see an amp input limit which is a little fishy.
 
your combiner is only 30 Amps output you will choke your bike and lose all sort of power,
depending on how you wire them, series vs parallel, it could blow it, i dont see an amp input limit which is a little fishy.
Well like I said I only turn on 1 battery at a time. Example: I have a 48v 30 amp battery. I went to walmart on my bike. is 13miles on way. I live in the mountains. I have a 4 mile ride up a mountain. Total Mileage is 26 miles. When I got home I still had 2 bars left on my #1 battery. I never turned on battery #2. So far it's working for me. Average speed 20 to 25mph.
 
Well like I said I only turn on 1 battery at a time. Example: I have a 48v 30 amp battery. I went to walmart on my bike. is 13miles on way. I live in the mountains. I have a 4 mile ride up a mountain. Total Mileage is 26 miles. When I got home I still had 2 bars left on my #1 battery. I never turned on battery #2. So far it's working for me.
30amp is terribly low but they are small batteries i see, only 13AH
 
30amp is terribly low but they are small batteries i see, only 13AH
Not sure what you mean. My batteries have Samsung 21700 cells and is 30amps and has a 35amp BMS. Well like I said the batteries work for me!

Here is the batteries I bought:
 
Links to eBay may include affiliate code. If you click on an eBay link and make a purchase, this forum may earn a small commission.
Greetings, I am in the process of setting up a dual 48 volt battery system on my DIY E-bike. I installed a conversion kit on a mtb I have about a year and a half ago and it's been decent for the most part but some of my commutes push the battery to it's limits and if I forget to put my battery on charge right away I don't make it home and either have to pedal which sucks worse than it did before I had the motor or jump on public transportation and on the way home is the worst time to have a dead battery. I just want to be home.

I already ordered 2 new batteries which are exactly the same as the one that came with the kit. They are 48 volt 13aH Hailong style. I was originally planning to get ones with more capacity such as 15 to 20 aH but they are significantly more costly and I found a deal that just could not n be passed up on the ones I got. They are regularly priced at $249 each. I saw a coupon for $30 thinking it would be only for the second one but when I checked out both batteries were $30. I couldn't believe it, my cart subtotal went from over $500 to $152 and change as I also had a couple of other things with the batteries.

Which brings me to the reason I am posting. I won't have the batteries until sometime between May 1 to May 7th so in the meantime I've been doing more research into the wiring. I have a decent grasp on most of it and I'm capable of doing the actual work involved because none of the batteries nor the controller have the common connections that the adapter has on it so I'll be doing some custom wiring work, which I more than likely would have anyway because I want to keep things neat and as tight to the bike as possible.

My confusion still lies with the balancing/equalizing of the batteries. The new ones are coming from the same supplier at the same time however I know that's no indication that they will be matched voltage wise. The adapter I bought is more than just a wire jumper, it has a device of some kind wired into the line between the 2 inputs and the output and it's called a dual battery pack discharge adapter however from what I can gather it sounds like I still might need another device to actually do the balancing!/equalizing. If anyone has any input on this, it would be greatly appreciated.

Dual Battery Pack Switch Balancer, 20V-72V Double Battery Discharge Converter Providing Lasting Power for Electric Bike https://a.co/d/fRoplEY

This is the device o bought a along with 3 of these...

DROK 48v Battery Meter, 10-100v Marine RV Battery Capacity Volt Monitor 12v 24v, Lithium Battery Voltage Fahrenheit Temp Indicator Gauge https://a.co/d/1EdhEbP

This is what I'm curious to know if I need as well?

LiTime 48V Battery Equalizer, Active Balancer for 24V/36V/48V Battery Bank, Supports for LiFePO4 Lithium Battery, Lead Acid, Gel, FLA, SLA Battery, Perfect for RV, Solar, Trolling Motor, Off Grid https://a.co/d/6rWWFS9
I run two batteries in parallel, both came from a company called greenlance. 48v 17ah & a 48v 20ah & I'm using a blender 20v - 72v. The batteries have a 40amp bms & so does the blender, my controller draws a maximum of 30amps & my rear hub can be run either as a 250w or 1000w though the controller can put out a maximum of 1440w, 48v x 30amps. Using pas 1-3 out of a maximum of 5, I'm averaging 33 miles on the 20ah battery & a little less in the 17ah. I'm 15 stone aged 60 & my bike uses a hybrid frame, 27.5 front & a 26 rear hub, both are running 1.95 tyres. One battery is frame mounted & the other on the rear rack
 
Links to Amazon may include affiliate code. If you click on an Amazon link and make a purchase, this forum may earn a small commission.
Here is the batteries I bought:
Part of the problem with buying cheapie batteries on Ebay or AliExpress is you are often dealing with fly-by-night operations whose commitment to truth in advertising can be dubious.

Unfortunately, the link above points to an obvious example of this: There is no way, no how you can get 30ah (you said 30 amps but the unit of measure is amp-hours) of 48v output into that Hailong case. The fact they claim it has Samsung 21700 cells inside doesn't make it possible, either.

The illustration they are using is of a standard size pack commoonly referred to as a Super Shark. Even if you go two sizes up to a Jumbo Shark, the max capacity for a 52v pack is going to be in the ballpark of 20ah... which still ain't even close to 30ah.

Thats probably a 15ah pack at best.

As for battery blenders, the problem with the cheap ones that are now getting to be common is the quality control used in their manufacture is totally unknown. Here again you are trusting your home fire insurance deductible (and the value of your possessions) to a complete unknown. A quality battery parallel box like a DateX has a cost roughly 10x what the cheap stuff goes for, and its worth noting the blender is governing a process that, when it fails, often fails catastrophically.
 
Links to eBay may include affiliate code. If you click on an eBay link and make a purchase, this forum may earn a small commission.
Part of the problem with buying cheapie batteries on Ebay or AliExpress is you are often dealing with fly-by-night operations whose commitment to truth in advertising can be dubious.

Unfortunately, the link above points to an obvious example of this: There is no way, no how you can get 30ah (you said 30 amps but the unit of measure is amp-hours) of 48v output into that Hailong case. The fact they claim it has Samsung 21700 cells inside doesn't make it possible, either.

The illustration they are using is of a standard size pack commoonly referred to as a Super Shark. Even if you go two sizes up to a Jumbo Shark, the max capacity for a 52v pack is going to be in the ballpark of 20ah... which still ain't even close to 30ah.

Thats probably a 15ah pack at best.

As for battery blenders, the problem with the cheap ones that are now getting to be common is the quality control used in their manufacture is totally unknown. Here again you are trusting your home fire insurance deductible (and the value of your possessions) to a complete unknown. A quality battery parallel box like a DateX has a cost roughly 10x what the cheap stuff goes for, and its worth noting the blender is governing a process that, when it fails, often fails catastrophically.
As far as the blender goes I do not run both batteries at the same time and never will.

Ok thanks for your reply. ;)
 
Part of the problem with buying cheapie batteries on Ebay or AliExpress is you are often dealing with fly-by-night operations whose commitment to truth in advertising can be dubious.

Unfortunately, the link above points to an obvious example of this: There is no way, no how you can get 30ah (you said 30 amps but the unit of measure is amp-hours) of 48v output into that Hailong case. The fact they claim it has Samsung 21700 cells inside doesn't make it possible, either.

The illustration they are using is of a standard size pack commoonly referred to as a Super Shark. Even if you go two sizes up to a Jumbo Shark, the max capacity for a 52v pack is going to be in the ballpark of 20ah... which still ain't even close to 30ah.

Thats probably a 15ah pack at best.

As for battery blenders, the problem with the cheap ones that are now getting to be common is the quality control used in their manufacture is totally unknown. Here again you are trusting your home fire insurance deductible (and the value of your possessions) to a complete unknown. A quality battery parallel box like a DateX has a cost roughly 10x what the cheap stuff goes for, and its worth noting the blender is governing a process that, when it fails, often fails catastrophically.
30 +or - 1amp controller, one 48v 20ah & one 48v 17ah battery with a DBB6040 double battery pack balance discharge (input 20-72DC output 20-72v/MAX40A blender) & don't get snotty about terminology, the last person to do that, got a punch on the nose
 
A 30a battery can provide a steady 30 amps maximum.
A 30ah battery contains 30 amp hours of charge.
The two are very different.
Come punch me if you really want to.
 
A 30a battery can provide a steady 30 amps maximum.
A 30ah battery contains 30 amp hours of charge.
The two are very different.
Come punch me if you really want to.

Why so hostile in this thread. Look ok my bad I said 30amp. ok so I misspoke my bad. I should have said 30ah. Look I'm good with 30 to 35 miles with just one battery. Now that I have 2 batteries installed I can now get 60 to 70 miles total with 2 batteries. Example: Wally World is 13 miles from my house. That's 26 miles round trip and I still have 2 bars left on my battery. ( I did not even have my second battery turned on ) I can't complain when I have a 4 mile ride up a mountain to get home. I weigh 175lbs and I ride around 20 to 25mph. Now just for fun on a flat road with no hills I can get a top speed of 31mph. I see no reason to go any faster than that. I love my bike and the batteries I bought. I have no complaints at all. I would recommend my Keteles K800 Mountain Bike with 2 1000 watt motors to anyone. Like I said I have no complaints at all with my bike.

Peace ;)
 
30 +or - 1amp controller, one 48v 20ah & one 48v 17ah battery with a DBB6040 double battery pack balance discharge (input 20-72DC output 20-72v/MAX40A blender) & don't get snotty about terminology, the last person to do that, got a punch on the nose
Big talk. (p.s. my screen name is my real name).

I wasn't snotty about terminology, either. I corrected a newbie mistake. Its better when people understand what they are talking about, and no shame in not being up to it without a helping hand. Especially in a medium where technical descriptions make a difference.
 
Why so hostile in this thread. Look ok my bad I said 30amp. ok so I misspoke my bad. I should have said 30ah.
Ignore him. Not @Atavar he was just responding to anonymous tough guy hiding behind his keyboard.

Mixing up amps and amp-hours is a common newbie mistake and I just corrected it in the interests of ensuring everyone is on the same page. Its no big deal.

You can get enough performance out of your two batteries to do everything you want. Unfortunately, the seller lied about the pack capacity (they also fibbed about the 1000 cycle lifetime; its more like 800 with a li-NMC if you treat it just right using say an 80-30 use cycle. You probably have a 30ah pack between the two of them. Which is quite a lot.

BTW I have been paralleling packs for many years, but doing so directly without a blender, matching the pack and cycle count, and the individual cells (making sure the charge capacity is as close as possible cell to cell within the manufacturer's spec) inside each pack. So its not like I hate on the concept. It just demands a fairly high level of care to do safely. A few years ago I stopped paralleling and went to bigger custom packs to eliminate the risks.
 
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