DieselTech
Well-known member
I reccomend you get some good torque arms for your front hub motor install. It will help save your front fork & keep the wheel from coming out of the fork.
To readers you will see my post a couple down from this post where I echo this member's comments. Note I posted my post before I read this member's post.
m@Robertson
Well-known member
As noted above, battery blenders are a bad scene, but I don't like them for an entirely different reason. They are black boxes whose actual quality and capability cannot be scrutinized or evaluated. You have no idea what was done in the manufacturing process, and that device is now a gatekeeper to what is potentially a bomb in your garage.
EDIT: Its for this reason I parallel battery packs directly. But its a potentially very dangerous process where there is a lot that has to happen to make it reasonably safe, and this goes all the way back to the buying and configuration process for the parallel'd packs before they were even assembled. Because of this, and the fact that if you have to ask how, you shouldn't be doing it, I never publicly get into the details. But its no secret you can find this info publicly. The Luna forum comes to mind where there is some pretty extensive info.
If you are going the 2-battery route, make it easy on yourself. You already have two controllers. Get two throttles and two displays. Two entirely independent systems. Plug one battery into each. The people who want one throttle on 2wd systems only do so because they don't know what they are missing by having two, and independent control over both wheels. Don't shortchange yourself when you are already going to all the trouble of adding 2wd... don't give up one of the nicer benefits that comes with it.
Once you get some experience, the next move is to buy one big battery with one big BMS, power both axles with it and leave all this parallel stuff behind.
Once you get that working, you can branch out and do splitters for your brake cables so pulling one lever shuts off both motors (initially, make your front brake shut off your front and your rear shut off the rear... that works well enough you may never go further with it). What you want to do no matter what is a splitter for your PAS sensor so you will have PAS enabled for two motors, which is another huge benefit of 2wd.
Lots of stuff here on how to avoid doing a v1.0 build with v1.0000 mistakes.
talesontwowheels.com
Do your job right and people won't even realize you have one display on the bars, never mind two.
![20230608_181518[1].jpg](https://ebikesforum.com/attachments/20230608_181518-1-jpg.10690/ "20230608_181518[1].jpg")
EDIT: Its for this reason I parallel battery packs directly. But its a potentially very dangerous process where there is a lot that has to happen to make it reasonably safe, and this goes all the way back to the buying and configuration process for the parallel'd packs before they were even assembled. Because of this, and the fact that if you have to ask how, you shouldn't be doing it, I never publicly get into the details. But its no secret you can find this info publicly. The Luna forum comes to mind where there is some pretty extensive info.
If you are going the 2-battery route, make it easy on yourself. You already have two controllers. Get two throttles and two displays. Two entirely independent systems. Plug one battery into each. The people who want one throttle on 2wd systems only do so because they don't know what they are missing by having two, and independent control over both wheels. Don't shortchange yourself when you are already going to all the trouble of adding 2wd... don't give up one of the nicer benefits that comes with it.
Once you get some experience, the next move is to buy one big battery with one big BMS, power both axles with it and leave all this parallel stuff behind.
Once you get that working, you can branch out and do splitters for your brake cables so pulling one lever shuts off both motors (initially, make your front brake shut off your front and your rear shut off the rear... that works well enough you may never go further with it). What you want to do no matter what is a splitter for your PAS sensor so you will have PAS enabled for two motors, which is another huge benefit of 2wd.
Lots of stuff here on how to avoid doing a v1.0 build with v1.0000 mistakes.
Dual Motor AWD Electric Bikes (the good and bad)
I like to build top-quality-component ebikes from the frame up. Quite a few of them are dual motor or AWD or 2WD or whatever you want to call them. Why would you build an AWD ebike?
talesontwowheels.com
Do your job right and people won't even realize you have one display on the bars, never mind two.
m@Robertson
Well-known member
If I remember right that is Micah Toll's tutorial on how to do that (one throttle and two controllers). Again I'll say you don't want to do this, but he's the guy who did a full video on how to do it. I think his channel is something like 'ebike school' or something. You can find it using his name I am sure.
If a eBike owner - on his own- was to hook-up (2) batteries in Parallel - in Parallel Hook-Up - the higher voltage battery would "dump" into the lower voltage battery - and YES that "rush-to-balance" - that flood of current from one battery to the other - yes that flood could overwhealm the BMS in either the Giver Battery or the Receiver Battery battery or could overwhealm both.
The perils of that "parallel eBike battery connection" are very real - and that's what this dude/or-dudette is ranting about - that Parallel connection can overwhelm either battery's BMS - or overwhelm both . .
With me when the music in my head gets too loud - the noise in my head can prevent me from hearing your knock on my door !
A legitmate Battery Combiner is a Voltage Sensing Gateway -- draws from Higher Voltage Battery 1st - and ONLY draws from both batteries at the same time WHEN the Voltage's of both batteries are matched. When the battery voltages are matched - there is no "food of current" from one battery to another - and all remains well !
CLIICK HERE FOR SENSIBLE EXPLANATION EBIKE BATTERY COMBINER
The perils of that "parallel eBike battery connection" are very real - and that's what this dude/or-dudette is ranting about - that Parallel connection can overwhelm either battery's BMS - or overwhelm both . .
With me when the music in my head gets too loud - the noise in my head can prevent me from hearing your knock on my door !
A legitmate Battery Combiner is a Voltage Sensing Gateway -- draws from Higher Voltage Battery 1st - and ONLY draws from both batteries at the same time WHEN the Voltage's of both batteries are matched. When the battery voltages are matched - there is no "food of current" from one battery to another - and all remains well !
CLIICK HERE FOR SENSIBLE EXPLANATION EBIKE BATTERY COMBINER
"Black Box's" - unless your are a OEM customer working to develop a Custom Component .. ALL eBike System Components are "Black Box" meaning no manufacturer publishes details of that component's circuitry. In the case of Controllers - more and more of the newesr models are filled with epoxy on top of that. - Controller/Battery-BMS/Display in essence are "Black Box.s" and result in a sizeble # of the posts on this forum.> Sure Encourage-The-Upgrade - but accurate answers are needed on this forum to correct unintentional mis-direction will take someone down a fruitless path.
The "most effective" rip-and-run configuration in my experience for a Q1 would be to install a RM GM062 as the rear hub motor - do Dual 52V batteries (2X 52V -21700 Cells - 15.7AH) and a decent 30-35A controller - and that Q! will be righteous. Frack ading a front motor - the rear upgrade with batteries will push that Q1 "hard" - ask anyone who has owned or ridden a Ariel X-Class and Ariel-Grizzly (oop's that's me agasin- dang it). You can ould take the money "saved" by not going over the top - and put that towards my next eBike to add the your growing eBike fleet.
The "most effective" rip-and-run configuration in my experience for a Q1 would be to install a RM GM062 as the rear hub motor - do Dual 52V batteries (2X 52V -21700 Cells - 15.7AH) and a decent 30-35A controller - and that Q! will be righteous. Frack ading a front motor - the rear upgrade with batteries will push that Q1 "hard" - ask anyone who has owned or ridden a Ariel X-Class and Ariel-Grizzly (oop's that's me agasin- dang it). You can ould take the money "saved" by not going over the top - and put that towards my next eBike to add the your growing eBike fleet.
There is a joke in my family that when I was 8 years old, I read the entire 24 volume set of the Encyclopedia Britannica. This is not true, I was 9 and I stopped at Q. It rained a lot that summer.
I am not an Electrical Engineer. So, I read the opinions of those who have such credentials. LOTS of them, also very experienced practical engineers, long-term users, etc. HUNDREDS of them.
A BMS functions solely and completely by reading voltages, which are INTENDED to be completely internal to the battery itself. When you combine, or parallel, two or more batteries, those readings are no longer solely internal to the individual battery, but are instead an average of the combined batteries. Individual weaknesses are masked. Dangerously over-discharged cell groups are no longer accurately detectable.
The BMS is no longer able to do its job, to be technical, the BMS itself has not been "bypassed", but the accuracy of its voltage readings has.
Whatever, I have no product to sell, so I really don't care. I will not put a 1500 watt motor on a front fork, and I will not parallel my ebike batteries. If any particular user disagrees with my opinions, when the mob is clearly more concerned with not hurting anyone's feelings than preventing a dangerous situation, I am willing to let them go wherever they like in their handbasket.
I will point out one more time that NO ONE, other than legally unreachable Chinese manufacturers, is offering such a device.
I am not an Electrical Engineer. So, I read the opinions of those who have such credentials. LOTS of them, also very experienced practical engineers, long-term users, etc. HUNDREDS of them.
A BMS functions solely and completely by reading voltages, which are INTENDED to be completely internal to the battery itself. When you combine, or parallel, two or more batteries, those readings are no longer solely internal to the individual battery, but are instead an average of the combined batteries. Individual weaknesses are masked. Dangerously over-discharged cell groups are no longer accurately detectable.
The BMS is no longer able to do its job, to be technical, the BMS itself has not been "bypassed", but the accuracy of its voltage readings has.
Whatever, I have no product to sell, so I really don't care. I will not put a 1500 watt motor on a front fork, and I will not parallel my ebike batteries. If any particular user disagrees with my opinions, when the mob is clearly more concerned with not hurting anyone's feelings than preventing a dangerous situation, I am willing to let them go wherever they like in their handbasket.
I will point out one more time that NO ONE, other than legally unreachable Chinese manufacturers, is offering such a device.
m@Robertson
Well-known member
It is super easy to deal with that instant-equalization issue you are talking about as a dump/flood. Thats just one small issue among several. A battery blender is not the magic solution to that although it may keep you from having to deal with the issue manually (which is simple to do).
Yeah but I have to trust you to tell me the truth about your manufacturing practices and quality control. You saying "trust me I know what I'm doing" is never going to carry any weight.
The one battery blender I have, I bought because I trust the vendor who sold it to me, after they earned that trust by my working with them on multiple projects and learning from experience they are not some yahoo. They have demonstrated with their actions to me and to others I know that they have genuine expertise and are trustworthy.
DieselTech
Well-known member
May I ask the brand of blender you are using? Also is battery blenders/combiners all rated at 30-35 amps max. Thanks.
m@Robertson
Well-known member
Not true. The DateX comes from I believe the UK, and its difficult to buy from the original developer because for some reason he seems incapable of doing a grown-up web site. I know of two others that came from two different vendors who are USA-based and did the internal specs of the products themselves. I don't believe either is sold any longer because neither took off as a product. I never bought either of them because they didn't support high amp levels which they have to to be actually useful.
The BMS of each individual battery is self-contained within each pack and is unaffected by any solution that parallels multiple packs together. It will still balance cell groups inside a pack just fine. What is pretty much spoiled on most (not all) BMS' is its ability to control overvoltage on the cell groups during charging, since the second pack in line is being charged thru the output port, which has no overvoltage protections (unless you buy a BMS for your pack build that does have this).
You can get around this by disconnecting the two packs, charging each individually to equal voltage levels, then reconnecting them after the charge is complete. Not something I have ever wanted to do as connecting, disconnecting and reconnecting two packs repeatedly carries different risks that in my view are not worth taking.
m@Robertson
Well-known member
Sorry for liability reasons I won't go there. Parallel'ing packs is something I don't recommend even though I have done it for years, safely and without incident. I think I've already said here the thing to do is buy a single big pack with a big BMS.
I will say the one I have is still on sale in the marketplace, has a range of 20-72v and a 130a capacity. You can google it up with a little work
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Wut he said up there ^^^^^^^^^^^^^^^^^^^ 1 Big battery (in my opinion as well)
So dont stop at 60v, i have 2 of them 60v 35ah 60v 45ah BTRpower batteries with custom BMS on both.
I can say it is a huge difference, go for the 72v 40ah and you'll blow bubbles 'cuz yur so happy lol
So dont stop at 60v, i have 2 of them 60v 35ah 60v 45ah BTRpower batteries with custom BMS on both.
I can say it is a huge difference, go for the 72v 40ah and you'll blow bubbles 'cuz yur so happy lol
DieselTech
Well-known member
Thanks. I was just trying to learn a few things about blenders & curious who has the best blender on the market at this current time. That's why I been tagging along on OP thread.Sorry for liability reasons I won't go there. Parallel'ing packs is something I don't recommend even though I have done it for years, safely and without incident. I think I've already said here the thing to do is buy a single big pack with a big BMS.
I will say the one I have is still on sale in the marketplace, has a range of 20-72v and a 130a capacity. You can google it up with a little work
m@Robertson
Well-known member
Are you using their LFP packs? LFP is physically large but I really like the safety factor, coupled to the increased cycle count you get with that chemistry. But I've never been able to bring myself to take the plunge even on my big cargo bikes.
DieselTech
Well-known member
Are the LFP packs the batterys that claim 800-1000 charge cycles, with little cell degradation.
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Yeppers
Been using them for a couple years now with no problems.
They are heavy though.
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That red mongoose hitch with the big battery, feels like a fuel tank on a motorcycle twixt me legs
I really need to get that down lower
ebikesforum.com
I really need to get that down lower
IMG_20230808_193809.jpg
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I call that my redneck ghetto pimpebike LOL
DieselTech
Well-known member
I thought that was the grocery getter!!!
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that too that too
