Two batteries one controller

[Burlingtony65]

I have an ENVO kit on my Cannodale hybrid and I now have two 36v 11.6aH Batteries that I want to use to extend my cycling range. I have found some adapters but I’m not sure if they will work for my controller unit. I can just switch the good battery for the dead one but that seems kind of old school. Has anyone done this successfully?
Thanks in advance!

 

[Biggtac1974]

I have an ENVO kit on my Cannodale hybrid and I now have two 36v 11.6aH Batteries that I want to use to extend my cycling range. I have found some adapters but I’m not sure if they will work for my controller unit. I can just switch the good battery for the dead one but that seems kind of old school. Has anyone done this successfully?
Thanks in advance!

Sounds like a good plan.im sure you will figure it out

 

[Anton]

Make sure you connect the batteries in parallel so you end up with the same voltage 36V and double the amps 23.2Ah.

If you connect them right it'll be just like having a bigger battery. If you connect them wrong you'll end up with melted wires and or a fried controller.

The other way would be to put a DC battery switch and wire it so you can switch to the other battery when one is empty.

You're probably best going with the first option, as it will extend the life of the batteries, since you will not be draining them down as low as if you were only using a single battery.

 

[HumanPerson]

Would this work?

EUNORAU Ebike 24V/36V/48V/52V/60V Dual Battery Hardware Converter/Dual

Specifications: 1.Dual battery converter MAX 72V 40AH*2 2.WIRE 80mm include XT60 end 3.Size 51mm*40mm*12mm Black

au.eunorau-ebike.com

 

[Anton]

Would this work?

EUNORAU Ebike 24V/36V/48V/52V/60V Dual Battery Hardware Converter/Dual

Specifications: 1.Dual battery converter MAX 72V 40AH*2 2.WIRE 80mm include XT60 end 3.Size 51mm*40mm*12mm Black

au.eunorau-ebike.com

That looks interesting, could it be that this dual battery connector has some sort of diode protection? This would prevent a smoldering mess however, you do get a small voltage drop using diodes.

 

[Frogslayer]

Would this work?

EUNORAU Ebike 24V/36V/48V/52V/60V Dual Battery Hardware Converter/Dual

Specifications: 1.Dual battery converter MAX 72V 40AH*2 2.WIRE 80mm include XT60 end 3.Size 51mm*40mm*12mm Black

au.eunorau-ebike.com

Very interesting indeed. If not it's just an over priced y connector.

 

[Anton]

Actually I did a little diode research and you can get these Schottky diodes which only drop the voltage by around 0.15V to 0.46V. They also put off a little heat so you need a heat sink. By comparison, standard silicon diodes have a forward voltage drop of around 0.6V.

Considering the y-connector you shared @Frogslayer has a heat sink, I would say it it using either Schottky diodes or a MOSFET to protect polarity. It could also isolate the batteries from one another to avoid the fuller battery charging the flatter battery. It's hard to tell since the description doesn't really tell us anything. Nothing in the description about max voltage, max amperage or polarity protection.

Another simpler way would be to just put a fuse on the positive wire of each battery and then wire them together into

A diagram showing how to wire in parallel always helps (please disregard the voltage and amperage of the batteries in the diagram). Note that you don't have to wire it at the base of the battery terminals. You simply just bring the battery wires together and connect with plugs or solder - positive to positive and negative to negative on the batteries. Then connect the output positive to positive and negative to negative to the controller.

 

[powrtrip]

I build cross current protect cables....use button diodes.. 50 amp 400 volt... Same used in charger systems... DM me if interested.. price depends on connectors

 

[HumanPerson]

Speaking of heat sink, i'm gonna split one of these bitcoin miners in half and use half as a heat sink for the controller...ya think this will work?

https://i.ebayimg.com/images/g/eVAAAOSwIGJaOKBh/s-l400.jpg

Ride Safe Everyone!



HP

 

[HumanPerson]

I don't know but me thinks this will work as a heat sink https://image.dhgate.com/0x0/f2/albu/g5/M00/4F/9B/rBVaI1mnzgqAMp2nAADzA5JOjic566.jpg

 

[HumanPerson]

Dual Battery Converter - instantly double your riding range!

Have you ever wondered about what to do with all your old ebike battery packs ? Watt Wagons is introducing an incredibly easy way to use your old battery packs and double your riding range. This converter will only work with two packs of the same voltage (e.g. 2x48v, or 2x52v).

wattwagons.com

This is discontinued on the wattwagons.com Website

 

[razz]

Can the dual battery converter be used with different spec batteries? Have an original 48v-14Ah battery on my radmini4. I'm interested in adding a 52v17Ah battery. Should I run them one at a time, or should I run them in parallel?

I've emailed "Electo Bike World" and was told running parallel batteries of different specs, degrades the batteries quicker. Can anyone comment?

 

[yohon]

Very interesting indeed. If not it's just an over priced y connector.

I just installed one of these and have a question I cant seem to find an answer to, maybe you can help me out. with this unit installed Will both batteries charge with the charger hooked up to one battery or do I still need to charge each battery separately.

 

[Anton]

Can the dual battery converter be used with different spec batteries? Have an original 48v-14Ah battery on my radmini4. I'm interested in adding a 52v17Ah battery. Should I run them one at a time, or should I run them in parallel?

I've emailed "Electo Bike World" and was told running parallel batteries of different specs, degrades the batteries quicker. Can anyone comment?

It depends on which type of dual battery converter you are using. Some of them can support batteries with different specs. When charging, always use the correct charger for each individual battery. Don't mix and match chargers.

 

[Anton]

I just installed one of these and have a question I cant seem to find an answer to, maybe you can help me out. with this unit installed Will both batteries charge with the charger hooked up to one battery or do I still need to charge each battery separately.

It would be safest to unplug and charge each battery separately. Did your dual battery converter come with a manual? Can you email the manufacturer?

@HumanPerson do you have some more insights into charging with a dual battery converter?

 

[HumanPerson]

Hey ya'll

Ok so i use this one explicitly for the Aventon Aventure, https://electricallwheel.com/dual-battery-discharge-balancer-kit-40a-aventon-fit/

I always unhook the extra battery before charging. I believe that charging them seperately is Safer than charging both together,
especially for me..my memory is not so good anymore lol

Yeah, @yohon which Dual Battery Discharge Balancer did you use?



Charge the batteries seperately..unplug the batteries...
if one cannot be bothered to do that then you may blow your house and family up or burn them to a crisp..don't do that!

Here is some reading :

https://biggamebikes.com/product/datex2-parallel-battery-adapter/


https://www.sparkcycleworks.com/index.php/product/battery-blender

E-bike Polar Bear Dual Battery Combiner 50A (2 in 2 out) With 2 XT 60 Cables — Fat Tire House

This dual battery setup for most of ebike up to 2000w During use the battery with the higher voltage will power the bike until such time when both batteries have equal voltage, then both batteries will power the bike simultaneously, giving you the combined current of both. The batteries should have

fattirehousela.com

Not all of the DBBDs (Dual Battery Discharge Balancers) will accept batteries of different voltage so people MUST READ on these websites.

 

[yohon]

It would be safest to unplug and charge each battery separately. Did your dual battery converter come with a manual? Can you email the manufacturer?

@HumanPerson do you have some more insights into charging with a dual battery converter?

China, ebay, no manual. From you answer to my post I can tell It was a mistake to buy it. also from your reply I have decided to remove it and just run one battery at a time. cons out way the good, I don't see much advantage to the unit any more. Thanks.

 

[rokkelectricbike]

Excellent explanation – thanks!
Can I assume if I was using a trickle charger for a single battery, I can continue to use that for a parallel setup?

 

[kmccune]

China, ebay, no manual. From you answer to my post I can tell It was a mistake to buy it. also from your reply I have decided to remove it and just run one battery at a time. cons out way the good, I don't see much advantage to the unit any more. Thanks.

use a double throw switch.

 

[m@Robertson]

Excellent explanation – thanks!
Can I assume if I was using a trickle charger for a single battery, I can continue to use that for a parallel setup?

If you are charging a pair of connected packs thru the single charge port of one pack, since electricity flows just fine in both directions your second pack will charge thru the connected output port.

What will also happen is your BMS' overcharge protection will be bypassed on the second pack, since power is going to be coming in from a place the BMS is not monitoring. Possibly balance functioning will also be bypassed. You would really have to have a pretty good understanding of your pack's internal components and specifics on your BMS' feature set to know for sure on everything, but its a safe bet at least that overcharge protection on #2 is gone. If Pack #1 is in good shape this should be OK but on the Jenga board that is paralleling batteries, you are adding a risk factor, and probably that is the biggest one when it comes to doing parallel packs (aside from making the initial connection safely).

I personally parallel packs directly, leave them connected and charge both thru a single input port (except I got away from this and went to bigass single packs because of the charge risk). but I also made sure I start out with identical packs with identical parts and cells, where the seller matched the cell capacity by hand (as in a custom battery). Among other things. I don't trust the Chinesium battery blenders because you are trusting your home safety to a factory in the Far East who has zero accountability, and the whole channel has a reputation for cutting corners.