Author Topic: Victory Empulse TT: Battery Life - Best Charging Practices  (Read 320 times)

Ultratoad

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Victory Empulse TT: Battery Life - Best Charging Practices
« on: June 29, 2017, 03:58:31 PM »
Is it best for battery life to charge with 110 volts?  Should you charge to 100% after every ride?  Is it good to take the battery down to low occasionally?  Any helpful hints?  I want to do what I can to keep my Empulse alive and well....

siai47

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Re: Victory Empulse TT: Battery Life - Best Charging Practices
« Reply #1 on: June 29, 2017, 07:58:57 PM »
Everyone has an opinion on what's best for the battery.  There are a couple of things that most can agree on, beyond that opinions vary.  The number one and two things that can be agreed upon is first don't store the battery at a high charge level and second, don't store the battery at high temperatures.  Most information about Li-Ion batteries wants you to store at around a 50% charge.  Some say a little higher, some a little lower.  This is because problems can occur with the anodes and cathodes at high storage charge levels.  Our bikes when at 100% are very close to the max voltage per cell of 4.2 volts---way better to store at a nominal voltage of around 3.6 to 3.7 volts per cell and then charge just before riding.  Same thing goes for temperature.  Our battery works best at about 76 degrees.  So above freezing and below 76 is a good storage temperature.  Same goes for charging.  Let the battery cool before charging if possible.

As to charge levels, I would run no more than 80% charge level unless needed for a longer drive.  On the other end, no less than 30% on the discharge.  I know that isn't practical for most but you asked about long life.  If you need max range and run under 30%, don't drive at high speed or high power output as you can stress the cells low voltage limit which is around 2.75 volts.  On the temperature end, don't run the bike hard when the outside temperature is high as the bike has no active battery cooling system.

The bike needs to be charged for an extended period of time at least once a month to "balance" the cells.  Balancing only occurs after a full charge and might several additional hours to complete.

The bike's charger at full output is very low compared to the size of the pack.  You could double the output of the charger and still not be close to putting too much current into the battery.  So, L1 or L2 charging doesn't make any difference except L2 charging uses less electricity to complete the charge.  This is because the DC-DC converter and other sub-systems are "on" when charging.  These loads are running twice as long for L1 charging v.s. L2. 

One final thing on storage.  After getting to the 50% charge level it is important to pull the DC interlock plug.  There are several "vampire" loads that run all the time the bike has high voltage DC available even when shut down.  If you pull the plug the bike should be at nearly the same charge level you stored it at even if it's a year later.

Ultratoad

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Re: Victory Empulse TT: Battery Life - Best Charging Practices
« Reply #2 on: July 01, 2017, 09:51:31 AM »
Wow....  Thank you very much for taking the time to provide this valuable information....  It would appear that most of my thoughts on the topic of charging were incorrect....  Really appreciate it....

HadesOmega

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Re: Victory Empulse TT: Battery Life - Best Charging Practices
« Reply #3 on: July 08, 2017, 05:06:45 PM »
I had heard it is ok to keep it charged to 100% even for long periods of time.  If you were going to store it for an extended period of time you probably wanna keep it at 80%, kinda like a LIPO battery.  But I remember according to the manual it doesn't hurt it to be charged and sitting at 100%.  I think thats the same for cold storage also 80%
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00049 (AKA SopFu)

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Re: Victory Empulse TT: Battery Life - Best Charging Practices
« Reply #4 on: July 30, 2017, 11:33:07 AM »
I had heard it is ok to keep it charged to 100% even for long periods of time.

That is not true. Batteries are essentially a big chemical reaction. When the battery is fully charged, it has a lot of energy stored. Think of it like a balloon with air that is constantly trying to escape. When the battery is sitting with a lot of energy, some of it is going to find places to escape, and in a battery that is usually reacting with things that weren't meant to have a reaction - usually the electrolyte or the structure of one of the electrodes. These mistaken chemical reactions are almost always irreversible. The reason it is better to store the battery at a partial charge is that these freak reactions happen exponentially less. As Siai said, the actual proper SOC to store at is up for debate.

On the other hand, the absolute worst thing you can do to a Li Ion battery is run it completely dead. In that case the copper in the anode gets exposed and actually becomes active material. (it becomes a "copper ion" battery, sort of.) Once enough copper is reacted, the internal resistance increases and the ability for the cell to produce current decreases. That is also irreversible. This happening once is enough to brick the battery.

So, if you have an option between storing at full charge or empty, full charge is better. In the winter I bring mine down to 80% and then check it every month or two.
'03 SV650
'13 Empulse #49
Wheaton, IL