Most electric bikes come with a single
battery like THE BLACKBIRD here. Now some bikes like THE LANCER have
a single battery inside the frame. But then they have an option for a second battery
on the outside now what if you already have an ebike it's not designed for two batteries but you
want to put two on well that's what this is for. A lot of you have been waiting for this dual
battery parallel connector to get back in stock. Not only are they in stock but
it is a new upgraded version! The internals are completely different
and the outside has a new aluminum case to shed heat, so this is
going to perform much better.
The typical questions ….. How do these work? Can I use batteries of different voltage? Can I use batteries of different amp hours? I'm going to explain all of those
things and show you how to connect one. This is a battery off of one of THE
BLACKBIRD bikes and this is the cradle. This is the portion that's mounted to the frame. A lot of ebikes are going
to have something like this. If your bike doesn't have this, what it probably
will have somewhere, is a red and black wire. What sort of connectors at the end of
this can vary a lot now I wanted this connector to be as generic as possible
XT90 meaning these are good for 90 amp. These are common on aftermarket batteries which
is I assume what you're going to be using.
Normally you'd have the battery connector
go straight to your motor controller and there's nothing in between those two
connections that's where this guy comes in. Let's grab two batteries and plug them
in they each have their own connector parallel module plug one battery in plug
the second battery in and now the remaining connection goes to your motor controller it
really can be as easy as that if you have XT90 connectors on your two batteries and on your
controller so on something like the blackbird I would take the battery and mount it on the rear
rack now on something like THE LANCER if you've got room in the triangle obviously that's another
option and then we're just going to run this nice long cable down to the parallel connector our
second battery and the motor controller but if you look closely at this production blackbird
you'll see that uh-oh it doesn't use an XT90 it's actually using a slightly smaller XT60
now that's sufficient for the bike because that connector is rated for 60 amps and the bike can't
draw that much power but that means that this guy doesn't quite match up it's not plug and play or
is it we also have this XT90 to XT60 adapter set.
It's one two three adapters that come in the set Let's say for example your blackbird battery
has an XT60 connector well we can plug one of these in and now that will plug directly into
the stock blackbird battery but we bought an aftermarket battery which uses an XT90 connector
well no problem we can plug that one in right here and looking at our controller oh well it also has
an XT60 well that's not a problem we have this adapter here and we can use an XT60 going to the
controller so with these three separate connectors you can use any combination of XT90 or XT60 now
I fully understand that your bike may not have either of those in aftermarket batteries like I
said it's very very common but on stock batteries you could get bullet connectors you could get
Anderson connectors you could get some sort of a generic plug that we don't even know what to call
it and in those cases you will have to find some sort of adapter or make your own now let's cover
some of the technical specs for THE BLACKBIRD example I have here I've got a 52 volt battery
that is a 16 amp hour the second battery i have sitting up here is a 52 volt 17.5 amp hour so
the capacity of this one is a little bit bigger than this one and that's okay you can mix two
different batteries of different capacities I could for example take the stock battery off
move it to the cradle and i could mount a massive you know 20 amp hour triangle battery in the
middle and that's going to work perfectly fine the voltage however does matter you cannot
use say a stock 52 volt and a 48 volt the battery voltage between the two batteries must be the
same this is more than just a parallel circuit so if you hooked two 48 volt 10 amp hour batteries
in parallel you'd effectively have a 48 volt 20 amp hour battery you double your
capacity the voltage would remain the same that's not exactly how this little guy works now
the end result is the same thing but it's a little bit smarter than that with a standard parallel
connector if one battery is charged up to 54 volts and the other one had say a 50 percent charge and
was it say 48 volts 47 volts if you connected the two together there is a potential difference
in voltage there that is going to equalize it's going to happen very quickly and somewhat
dangerously you're going to instantly drop the voltage of one battery and raise the other until
they are equal so it's an instant rush of current from one battery to the other effectively
discharging one and charging the other at a higher rate than either of them can handle
and potentially kill the BMS or the cells in both batteries obviously we don't want that so this
being a little bit smarter is also a little bit safer you see if we have two batteries
that are not charged evenly this will draw from the battery with the higher voltage
until the batteries equalize at which point it can draw from both of them together and that's
something that might look a little odd on your display of your ebike if you have one battery
that is halfway charged and one that's full your motor controller that's plugged in is only
going to see the battery that is fully charged and operating you can always plug them in one at a
time to ensure what your actual charge levels are you can also run off of one or the other battery
you don't have to have both of them plugged in at all times this is good for anything from 24
volts up to 52 volts and you also probably want to know how much current this can handle the maximum
recommended current for this is 30 amps so just something to be aware of it does have a very nice
aluminum case that should shed the heat but it is only rated for 30 amps so if you have one of those
35 amp controllers and you're going to use one of these you may want to tune it down just slightly
so it maxes out at 30 amps now that's going to cover most stock electric bikes on the market
usually 20 or 25 amps is as high as a stock electric bike will go even the 1000 watt BBSHD
equipped bikes those controllers are either 28 or 30 amps so can handle that without any changes
these are in stock at BOLTON EBIKES DOT COM The adapter set to the XT60s are also in stock one thing I don't have quite yet is a
specific mount designed for it to put it on the bike and it's pretty small and
compact it can go in a lot of places.
But if you'd like to see a custom designed
mount for these let me know in the comments i'm thinking about actually making
one and putting it into production. Just let me know if you're
looking for a case or a mount to put this on your bike and we'll
try and get to work on that right away If you're considering putting two batteries
on your ebike you should probably know how to maintain them for nice long life i
have a great video on that right here..
