Installing the Battery

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A single cell is not a battery. A battery is made up of two or more cells. All electric bike batteries are made of certain brand cells and the better the cells the more expensive the battery. High end cells are those made by Sanyo, Panasonic, LG, and Sony. Also, there is the generic cell. Generic cells are cells manufactured in China. Generic cells are not inferior, mislabeled, or counterfeit cells. Generic cells are 18650 Lithium Ion cells that do not carry the brand name of premium cells. If a company producing batteries were corrupt they would not be using generic cells. They would be using counterfeit Sanyo, Panasonic, LG, and Sony cells. I cannot stress this enough, always buy your battery from a trusted source. Before purchasing your battery ask: "Who built this battery?"

First, never open a battery case. It can be very dangerous. Above is a picture of a very poorly constructed electric bike battery. While this is one example, we have seen much worse. Corrupt sellers of these batteries always seal the battery with tamper proof seal forbidding opening the case without voiding the warranty. If one opens the case and sees a terribly constructed battery there is nothing that can be done because the warranty has been voided the moment the case was opened. 

This is what we like to see. Under the blue heat shrink there are cell holders on each side of the 18650 cells. The cell holders hold the cells in place and allows cooling between each cell. The reason we stopped using the 52v downtube battery is the extra cell prohibits the use of the cell holders and thus causing the battery to have the potential of running warmer than necessary. 

This is an example of the use of cell holders. As you can see each battery is held separated from the one nest to it. The cell holders can be cut to adapt to any size or configuration of an electric bike battery. The use of the cell holders help prevent the cells from coming into contact with one another in the event the battery pack is dropped or damaged. 

It's not as if these are ticking time bombs that need to be pampered, but one always has to be mindful of the fact that  a damaged electric bike battery can be a ticking time bomb. A nine pound battery can be easy to drop when removing. If at any time your battery hits the ground, even though you see no visible damage, charge the battery outside and not in an enclosed area. As you are charging the battery periodically put your hand on the case and check for any hot spots. If the case is hot then stop charging and call an electric bike shop for advice. Do not open the case, do not attempt to repair.

There are many electric bike battery chargers available but as a matter of safety always use the charger that came with your battery. If you do buy an aftermarket charger there are two things to consider. First, is the charging cable. Make sure it matches your battery. It might be a small barrel connector, or the larger XLR. The second matter is make sure you have the correct voltage!!!! Do not use a 52v charger on any battery other than a 52v battery. Never use a charger whose voltage is higher than the battery you are charging. If you are unsure, take a minute and call your local electric bike shop and they will help you find the correct charger for your bike.

This is a typical downtube battery. It is designed to attach to the water bottle inserts on the downtube of the bike. Because of the weight of these batteries it sometimes is necessary to use an adaptor, large Zip ties, or install an additional 5mm insert. These batteries can weigh up to 10 pounds. In my opinion, I think it best to use the smaller lighter battery, such as the side release, as it only weighs 5 pounds 10 oz. The lighter battery is much easier on the base plate attachment points (water bottle inserts) and as a result less likely to damage the bike frame in case of a crash. It is far better to carry a second battery on those days you will be on a very long ride rather than have a large heavy battery that you only use half its range on your dailey ride.

What makes this battery different that a standard downtube battery is that is slides out sidewise. This feature allows the battery to fit in much smaller spaces. A standard downtube battery must have enough room to slide forward and up to both install the battery and remove the battery. If you have a full suspension bike it is highly unlikely a standard downtube battery will fit. In addition to its side release function, this battery only weighs 5 pounds 10 oz. In my opinion, the perfect solution is to always use the lighter battery and carry a second battery for those days you wish to ride 60-100 miles. Yes, you will pay more for two batteries but that is the best approach. 

This is a cube battery and you can find them in many different sizes. We used to carry a small cube battery that we would put in a tool bag and mount it behind the saddle. Cube batteries do not come in a protective case so you have to very careful while handling. When installing a cube battery on a bike it is imperative you enclose the battery in some kind of protective shell. Even a small cube battery being used behind the saddle has to have some kind of padding to keep it from abrading against any hard abject. Last year in Australia, during organized cycling event, a gentleman used a behind the saddle cube battery that was not properly protected against rubbing against the seatpost. Needles to say the battery caught fire and the bike was quickly engulfed.

These are typically 36v batteries and due to their small size have limited range. It is a mistake to assume that because it is called a bottle battey it will interface neatly with the water bottle inserts. The base plate still has to align with the water bottle inserts just like any other battery. Are there any advantages to using a water bottle battery? They are one of the least expensive batteries, due to their size, but other than that I would use the side release battery over the bottle battery. That said, the size, voltage, type, and shape of the battery will always be dictated by what will fit on the bike. If the bottle battery is the only battery that will fit the dimensions of a frame then the bottle battery is the best choice for that bike.

This is a massive 52v 20Amp triangle battery. This is a battery we rarely use due to its weight, which is significant. Again, it is my opinion that it is better to have two batteries with your electric bike with only one battery mounted at a time. Carry your second battery for those days you will be riding long distance.  Having a massive battery attached to your bike for 20-30 mile rides does not make sense.  These large triangle batteries do not fit well on bikes as the triangle of the bike frame (top tube, down tube, seat tube) rarely correspond to the triangular dimensions of the triangle battery. If you do purchase a triangle battery find one in a hard case, not a bag. Some triangle batteries have a on/off switch and others do not. Given a choice, find one with a on off switch.

These batteries can be large and heavy. In fact, I have yet to see one that was not large and heavy. Very rarely do we use a rack battery as people tend to not like them. Remember, to mount a bicycle it is often required you lean the bike in your direction then you swing your leg over the rear of the bike. When you tilt a bike with a rack battery you immediately feel the full weight of the battery. When you you swing your leg over the the rear of the bike you have to make sure you clear the battery. If, the weight of the battery is too much, or you unsuccessfully clear the battery with your leg you can drop the bike. Given a choice we prefer the downtube battery. However, sometimes the only choice will be some sort of rack battery.

This is an example of the downtube battery install. This battery is the typical 48v 13 top load battery. It is important when you use this type of battery to remember it will need room to slide forward about an inch and then upwards about a half an inch in order to install and remove for charging. Many, who are ordering a battery for their bike will measure the triangle area of the frame and then order a battery that will fit the triangle. Nope...that is not the way it works. There must be enough room for it to slide forward and up in addition to have room for the size of the battery. 

We have mounted batteries on the top tube of a number f bikes. It is not our first choice but sometimes there is no alternative. When mounting on the top tube I highly recommend using the smaller, lighter, side release battery. To install a battery on the top tube you will have to drill and insert Rivnuts. When possible, we use three Rivnuts. It is very difficult to install a battery on top of the top tube and should only be attempted by an experienced bike mechanic. 

On some full suspension bikes the best (if not only) place to mount a battery is on the bottom of the downtube. Most full suspension bikes do not have any way of attaching a rear rack which eliminates the use of a rack battery. Usually, there is no room on the downtube and mounting the battery on the top tube is best to be avoided whenever possible. Note: If you are going to mount the battery on the bottom of the downtube make sure the front tire does not come into contact with the battery when the fron suspension is compressed.

This is a Dahon folding bike being prepped for conversion. We always use the side load battery for small collapsing bikes. When attaching the battery cable to the motor remember to do it in such a manner that will allow the bike to fold. We take the battery cable and attach it to the existing cables on the bike (shift or brake).  By using the existing cables as our guide we know the bike will fold once the battery is installed. 

This well machined product is made by Terra Cycle (T-cycle.com) and is invaluable for installing a battery on a recumbent. It is an expensive item but it is very well made and worth the cost. There is no downtube on a recumbent bike and nearly every square inch is already accounted for and there space is limited. This product creates space for the battery and if you are converting a recumbent then I recommend you include the Terra Cycle battery base in your budget.

This was a custom build we did for a very nice gentleman. He was over 6' 9' and needed a very tall bike. Battery placement was going to be a problem as the frame was round tubes made of steel. The only place we felt we good get a secure fit for the battery was on the seat tube. This can only be done on bikes that have a very long seat tube. When we were finished installing the battery we were pleased with the result.  

On almost every bicycle there will be two small threaded inserts that are attachment points for a water bottle cage. If you are going to use a down tube battery these inserts will be your attachment points of the battery base plate. They will be 5MM in size. It seems a simple matter but it can become problematic real quick. For example, sometimes these inserts are to far back causing the battery to come into contact with the seat tube. Other times, the inserts are to far forward causing the battery to come into contact with the top tube. Again, some inserts will be in a position that not a single one will line up with the battery base plate. It is common to encounter the above described. It is important to be able to determine if your battery will fit prior to purchase as batteries cannot be returned because they are a Class 9 hazardous material.

This a adapter that can shift the inserts both for and aft. This is smaller size adapter. It also comes in a longer model. For the most part this can solve the problem of getting the battery on the down tube. Note, this adapter will raise the height of the battery and may cause the battery to come into contact with the top tube. Also, because of the weight of the battery the connection will not be as strong by using this adaptor. Always check the connection points on the battery plate to insure the screws a firmly in place. As stated before, it is always best to use smaller, lighter batteries on your bike. If more range is required then purchase a second battery to carry with you. 

We use hard rubber washers as an interface between the battery base plate and the bicycle frame. A hard rubber washer allows us to compress the base plate (or adaptor) firmly against the frame without damaging the frame. We have experimented with many types of washers (nylon, rubber, leather, and different types of metal) and have settled on a hard chemical resistant/weather resistant washer. Not only does a rubber washer make for a better interface than direct metal on metal but it also provides vibration resistance. A rubber washer will prevent the battery screws from loosening. However, always check your battery baseplate screws to insure they are tight.

This is a bike that came to our shop and the battery was falling off. The first thing we noticed was the battery was held in place with with wood screws. The weight of the battery and the use of wood screws pulled the battery right off the frame. Of course, this bike was damaged to the point it had to be destroyed. Why so many holes? The builder decided it was easier to drill holes in the frame rather than use a baseplate adaptor.

There are times when the use of Rivnuts will be necessary. A Rivnut is the same as a water bottle insert. At times it will necessary to drill a 5mm hole in the frame of a bike and install a Rivnut insert in order to fit a downtube battery. It is advised that this be done by someone skilled in using the proper tools required for this procedure. It is a "one chance" procedure and you have to get it right the first time.  

These batteries are powerful and can reult in injury if mishandled. Make sure red wire (+) goes to red wire (+) and black wire (-) to black wire (-). Do not short out your battery as you can be injured!!!! Be careful, do not mix alcohol/drugs/lack of sleep/fatigue/or anything that might impair your judgement when you work with these powerful batteries. Also, these motors have capacitors. Once power is supplied to the motor the capacitor will store energy. Do not short out the motor as injury can occur and can damage the motor.