Ion Batteries
 

Question, should Ion batteries be kept on the charger all the times when not in use?

Nope. Please refer to the link below for our recommendations.

http://www.mtobattery.com/portfolios...ttery-charging

While I respect MTO's knowledge, I have an 8-year old i2 with almost 12,000 miles on the original packs, and it has the same range as it did new. I've never used a timer; I just plug it in as soon as I arrive, and leave it plugged in until I need it again - just like the owner's manual says to.

So use a timer if you wish; it can't hurt, but it's not necessary based on my experience.

(I should note that I ride this i2 virtually every other day (alternating with another), year-round. Perhaps that's a factor in battery life.)

The big factor, as discussed elsewhere in the forum, is disconnecting and reconnecting the AC power.

Thanks gentlemen. GR

I believe the two plans are not as far apart as you may think.

The fact that you use your machines every other day, indicates that they are likely never kept plugged in any longer than 36 hours at a time.

My timer makes sure my machine cycles every 24 hours.

The huge difference is that my machine goes several weeks without use during the winter, and often a week or more during the summer without use.

Because of that, mine has the potential to be plugged in for several weeks without cycling the power without the timer.

Yours is never exposed to that.

I believe the primary advantage to the timer is not so much that the power is removed for 'x' hours a day, but rather that the charge cycle is started over and over, and the beginning of the charge cycle is very different than the end of that cycle.

If you leave your batteries plugged in for very long times, it only gets the advantage of the end of the cycle, and not the beginning. Using a timer, or plugging and unplugging it every day, adds all the other parts of the charge cycle...

So, even though you don't use a timer, your very use style is doing an almost identical pattern to charge your segway...

I suppose that's a valid point, although it doesn't really prove that the timer (or my riding style) increases battery life. I haven't found any other sources of information on charging Lithium Ion batteries that recommend periodically interrupting and restarting the charging cycle, but would like to read any that do to understand the reasoning, and see some proof. As I recall, someone on the forum came up with the idea on his own, and claimed some benefit, and others blindly followed. (Obviously, I'm still not convinced. :confused:)

Here's the reasoning - but feel free to not be convinced. And this is specific to the Segway charger (might not apply to other chargers).

Refer to http://www.segway.com/segway-resourc...nformation.pdf

See the stages described on Page 4. When started by plugging in the AC, the process goes through the first two stages, and then remains in stage 3 as long as the AC is available.

The charging process never gets back to stage 1 (initial test) to see if more charging is needed. The way to get back to the stage that tests the battery is to cycle the AC power. A timer does that.

MTO's suggested timer setting also recognizes that 8-10 hours of charge time is sufficient.

Maybe I misunderstood the objective. I thought it was to increase the overall life of the batteries. If it's to get maximum range per charge, then occasionally re-checking to see if additional charging is needed would make sense.

But even though the manual chart doesn't specifically say so, I'll bet that phase 3 includes trickle charging. Otherwise, using a timer would be recommended to ensure that going weeks without riding wouldn't deplete the pack that powers the radio board.

The major benefit from the timer is that the BMS within the battery and the Segway charging system have the ability to lock up during the charging process. This is much more likely to occur if the Segway is charging for extended periods of time but I have experienced this first hand in 2-3 weeks on my one machine. The timer resets the electronics in the charger which clears any fault there (unless it's hardware) and begins the process over. If the batteries are fully charged nothing new will truly be accomplished. If the batteries are slightly discharged it will top off. This practice will help prevent an CSB or BMS fault from allowing your machine to overdischarge the batteries. Cycling power and beginning the process over also keeps the BMS inside the battery from going into "sleep mode". After extended periods of time with no change the BMS will essentially shut down to save power. I advised the timer method because it is better than someone unplugging and plugging the machine in manually and forgetting from time to time. It is far better than someone leaving the machine plugged in for a year and coming back to red lights. I receive phone calls on that problem seemingly every week. I am not a Segway engineer but I have made recommendations based upon the characteristics of the battery chemistries and the limitations of the machines. I have equipment and software that enable me to monitor the Segway charging system and also access the BMS and see what is occuring at the cell level.

Now, there is also a benefit to the batteries. Do some research on lithium batteries and look at the life of a battery that is kept at 100% voltage all the time and one that is allowed to stabilize to nominal voltage. A lithium battery that is maintained at peak voltage will degrade at a faster rate than the same battery maintained at a lower voltage.

Reference:
http://batteryuniversity.com/learn/a...tore_batteries
(Please see paragraph below table 2)

"Elevated temperature and allowing the battery to sit at the maximum charge voltage for an expanded time explains the shorter than expected battery life. "

"All batteries should be able to relax after a charge by removing or lessen the charge."

Battery University is operated by Cadex corporation which is a leading name in battery analyzer equipment. They undeniably know their stuff.

In closure I would like to reinforce that I did not come up with this on my own. I have had extensive conversations with some of the members here on the forum whom did not blindly follow. You are able to make a choice on how to proceed with your batteries but as Karl has already stated it is pretty much irrelevant because you use your machine daily and all year round. Those who don't, will most likely not have the same results as you. In this case, as with many others, one solution does not fit all situations perfectly. I feel my recommendation is the best all round solution as it will work with nearly any usage level. I hope this helps shed some further light on this and I hope this information helps benefit the Segway community.