Second battery for cold starts

[Joseph189]

Hello, new here to r3owners.
Has anyone added a second battery to there bike? i live in Indiana and it gets pretty cold in the ridding season. my bike struggles to start in the morning after work and i was wandering if a second battery would work and how to go about doing it. I plan on doing to pod filter mod and getting rid of my airbox. i figure i could find a way to get the second battery to fit where the old filter was. I dont know much about batteries and i just want to make sure i do it wring and dont "fry" anything.

 

[TriumPhil]

You can get a higher capacity, stronger CCA, lithium ion battery for about 230 bucks or just keep your stock battery connected via a pigtail connection to a $25 Battery Tender Jr whenever your bike is parked in the garage.

 

[Tripps]

Someone here has a LI second battery

 

[HansO]

Firstly Welcome, there are some different solution, I currently am running the battery out of my unused Honda St 1100 sitting in the air-box and connected in pos to pos and neg to neg so it still maintains 12 volt with 60 amp cable, it works for me, there is also the heavier pos to starter and heavier neg to engine earth cables, and there are Li Po batteries available that are the same physical size as the Std battery but have up to 600 CCA but at a price, as funds allow I will be switching to a Li Po and the heavier cables

 

[dougl]

Get a battery tender.

 

[HansO]

While a battery tender may be good while starting at home but I don't have that problem of cold weather at home, the only time I have had the colder weather start problem is when I have been in land where it does get cold and a AC power outlet is not available to be able to run a battery tender

 

[barbagris]

Get a small LiFePO4 battery and run it in parallel to the Lead/acid. What is SMALL? - well 2.5aH would be enough - but 5aH would be a good average.
This is a solution suggested to me by several small town emergency services for making sure ambulances etc. fire up after being left a while unused.
Basically the LiFePO4 acts as an on-board trickle charger

The chemistries of batteries is such that LiFePO4 cells retain voltage as they drain - whereas lead/acid retain amperage as they drain.

MAKE SURE THE TECHNOLOGY is based on the correct type of cells. For the above capacities you need "A123 Systems ANR26650M1B" cells.
Like these

You'll need 4 in series to get the 12.8V needed.

In my old Guzzi I run a small lead/acid to keep the coils fed and a LiFePO4 (8aH) to fire the starter.
Headway has recently announced an 8aH HIGH discharge cell similar to the (now discontinued) 8aH A123 cells I used.
They're on my R+D list.

 

[Joseph189]

I do have a battery tender. Wich works but if i leave the bike for about 10 hours without plugging it in i wont be able to start it. I have tried a li battery. Same isue. I currently have all my accessories on a toggle swich for when i am away from home. If i wire two batteries and keep them 12 volts then i wont have to worry about frying anything.

 

[tdragger]

Welcome, Joseph. Glad to have you on the board. The cold start issues have been discussed at length. Mine also has that problem. There are a number of solutions to the issue and it is just a matter of which way you want to go.

Before getting to the options, there is one task that you must do prior to doing anything. The headlights and starter circuit are combined and routed through the ignition switch. Downstream of the switch the circuit is split using a relay (referred to as the starter relay). When you hit the starter button, the headlights go out and the starter is engaged. When you let off the starter button, the relay switches the circuit back to the headlights. It is a myth and a waste of money to get any sort of kit that "turns off the headlights until you start". The real issue here is the circuit running through the ignition switch. The combined load of the twin headlights will end up melting the solder joints in the switch and cause the switch to fail. The solution is to fit a headlight relay kit. You can build your own or as most of us have done purchase the Eastern Beaver kit (www.easternbeaver.com). This is really necessary as it is not a matter of if but when the ignition switch will fail.

Now for the cold start issue and possible solutions:

1. Tie a 2nd battery in parallel. This will require that you have made the intake mods so that you can drop a battery in the old airbox. Personally, I don't like this solution as it doesn't really resolve the source of the problem.

2. Replace the negative side battery cable. This is an easy job to make up a larger gauge cable and it makes a big difference. Search for the thread on doing this mod.

3. Fit a secondary starter relay. Remember the discussion above, the primary starter relay switches the load from the headlights to the starter and back again. The headlight relay kit addresses the load when in normal operation, however, the entire load of the starter circuit is still routed through the ignition switch. The secondary starter relay mod is similar to the headlight relay kit in that the load is redirected to a direct line to the battery. This means that the full energy of the battery is delivered to the starter rather than being consumed in line loss.

4. Fit a higher powered starter motor. The stock starter is a 1.2 kW unit. You can get a 1.4 kW replacement from the local auto parts store. It is a 15 min effort to switch the motors out. The result is a faster spin of the motor.

I would strongly recommend that you do options 2 and 3 above together followed by option 4 and finally option 1.

There are threads on this site for each of the options.

 

[Joseph189]

Welcome, Joseph. Glad to have you on the board. The cold start issues have been discussed at length. Mine also has that problem. There are a number of solutions to the issue and it is just a matter of which way you want to go.

Before getting to the options, there is one task that you must do prior to doing anything. The headlights and starter circuit are combined and routed through the ignition switch. Downstream of the switch the circuit is split using a relay (referred to as the starter relay). When you hit the starter button, the headlights go out and the starter is engaged. When you let off the starter button, the relay switches the circuit back to the headlights. It is a myth and a waste of money to get any sort of kit that "turns off the headlights until you start". The real issue here is the circuit running through the ignition switch. The combined load of the twin headlights will end up melting the solder joints in the switch and cause the switch to fail. The solution is to fit a headlight relay kit. You can build your own or as most of us have done purchase the Eastern Beaver kit (www.easternbeaver.com). This is really necessary as it is not a matter of if but when the ignition switch will fail.

Now for the cold start issue and possible solutions:

1. Tie a 2nd battery in parallel. This will require that you have made the intake mods so that you can drop a battery in the old airbox. Personally, I don't like this solution as it doesn't really resolve the source of the problem.

2. Replace the negative side battery cable. This is an easy job to make up a larger gauge cable and it make a big difference. Search for the thread on doing this mod.

3. Fit a secondary starter relay. Remember the discussion above, the primary starter relay switches the load from the headlights to the starter and back again. The headlight relay kit addresses the load when in normal operation, however, the entire load of the starter circuit is still routed through the ignition switch. The secondary starter relay mod is similar to the headlight relay kit in that the load is redirected to a direct line to the battery. This means that the full energy of the battery is delivered to the battery rather than being consumed in line loss.

4. Fit a higher powered starter motor. The stock starter is a 1.2 kW unit. You can get a 1.4 kW replacement from the local auto parts store. It is a 15 min effort to switch the motors out. The result is a faster spin of the motor.

I would strongly recommend that you do options 2 and 3 above together followed by option 4 and finally option 1.

There are threads on this site for each of the options.

Thabks so much. That was exacty the kinda info i was looking for. Ill be sure to look into all those options. Its kinda embarrassing to not have my bike start while the harly riders start up and take off right then and there.