Battery Conditioning

Hi.I know its been asked before but what is THE BEST WAY to charge/condition a new Battery !!!!!!!! its off a Freego Eagle and its 36v - 16amp.

Regards Steve

Allegedly running it flat (or as flat as the BMW allows) and then charging it up to full for 3-5 cycles is best for them. In reality I've never seen any real world evidence to support this on modern lithium chemistry batteries.

The best way I've found of extending the life of lithium batteries is not letting the voltage drop too low per cell, and charging at a sensible rate. Of course if you get them hot by fast discharging you would be doing them harm too, but that's not likely on a legal bike.

Allegedly running it flat (or as flat as the BMW allows)

 

Mine was a Ford;)

Ooops, BMS, my phone prefers BMWs it appears though.

Allegedly running it flat (or as flat as the BMW allows) and then charging it up to full for 3-5 cycles is best for them. In reality I've never seen any real world evidence to support this on modern lithium chemistry batteries.

 

According to the FreeGo manual, you need to fully charge the battery first, then do the 3-5 charge/discharge cycles to get the battery to come up to full capacity. BUT Most dealers would have already done this before selling you the bike/battery.

To get optimum life out of the battery most sources state it is best not to discharge the battery past 80% DOD

Be careful about this business of running down your battery to 80%. All this stuff is already looked after by the BMS and controller. All we have to do is charge them up until the light goes green, and run them down until they switch off (if you need to go that far).

 

The Freego manual doesn't mean that you have to cycle the battery 3-5 times before you can use it. Instead, it's just trying to make you aware that you shouldn't judge the bikes range until it's done a few cycles. No dealer wastes his/her time charging and discharging batteries before they sell the bikes (unless they misinterpret the manual).

The place where I got my FreeGo does cycle the batteries, as part of their quality control, before selling them.

I've a couple more questions about batteries that I hope someone can help with.

 

The first is about the use of chargers for different Li-ion and LiFePo4 batteries. In the family we now have 3 electric bike conversions – two with Li-ion batteries and one using LiFePo4 – and the batteries each came supplied with an independent charger. However, ALL chargers deliver the same charging rate, 42V at 2A, and I’m wondering whether there’s any reason one charger could not be used to charge all three batteries. I’m thinking specifically of taking just one charger when we’re on holiday.

 

My only worry is in the case of the LifePo4 battery where the charger has a case that’s kind of “universal” and which could be marked with an appropriate red dot for charging either Lead-acid, Lipo (I assume Li-ion), or LiFePo4. That tends to imply it’s important to match charger and battery and that current/voltage characteristics aren’t the only criterion important for charging.

 

So, I wonder if the charger and battery BMS need to be carefully matched, and whether I could use one charger indiscriminately.

 

The second question is about delivering a less than maximum charge to the battery so as to increase its longevity. Charging to only 80% is recommended in a few places and since our batteries are rarely fully discharged when we’re out riding, charging to only around 80-90% seems a sensible thing to do, especially because an extra year or more of use would save quite a few pennies!

According to the FreeGo manual, you need to fully charge the battery first, then do the 3-5 charge/discharge cycles to get the battery to come up to full capacity. BUT Most dealers would have already done this before selling you the bike/battery.

To get optimum life out of the battery most sources state it is best not to discharge the battery past 80% DOD

I do not believe that a dealer has time to run down and recharge a 16amp battery 3 to 5 times. With a 50mile range, this could be up to 250 miles of riding. The customer letting the battery go down to the last light on the control and then recharging 3 to 5 times is more realistic. Following the guidelines in the manual will maximize your battery life in most cases.

 

As for not discharging past 80%, I believe that the Freego type battery cuts out with 20% reserve left. I might be wrong but perhaps the Freego guys could clarify.

Hi Emo,

 

You are correct, there is no longer any need to put the battery through any charge discharge cycles now. The latest lithium batteries dont need this kind of conditioning, however they will improve a little over the first few uses.

 

All the best

 

David

I've a couple more questions about batteries that I hope someone can help with.

 

The first is about the use of chargers for different Li-ion and LiFePo4 batteries. In the family we now have 3 electric bike conversions – two with Li-ion batteries and one using LiFePo4 – and the batteries each came supplied with an independent charger. However, ALL chargers deliver the same charging rate, 42V at 2A, and I’m wondering whether there’s any reason one charger could not be used to charge all three batteries. I’m thinking specifically of taking just one charger when we’re on holiday.

 

My only worry is in the case of the LifePo4 battery where the charger has a case that’s kind of “universal” and which could be marked with an appropriate red dot for charging either Lead-acid, Lipo (I assume Li-ion), or LiFePo4. That tends to imply it’s important to match charger and battery and that current/voltage characteristics aren’t the only criterion important for charging.

 

So, I wonder if the charger and battery BMS need to be carefully matched, and whether I could use one charger indiscriminately.

 

The second question is about delivering a less than maximum charge to the battery so as to increase its longevity. Charging to only 80% is recommended in a few places and since our batteries are rarely fully discharged when we’re out riding, charging to only around 80-90% seems a sensible thing to do, especially because an extra year or more of use would save quite a few pennies!

 

Hi Thamossy,

 

Firstly it is massively important that you use the charger supplied with the battery, they are paired and do work with one another. The charge rates can vary typically from 2A to 4A. Using the incorrect charger is dangerous and could cause fire.

 

Secondly, it is best to fully charge your battery when possible whilst you are using the bike regularly. In the winter months however a 65% charge is ideal, as long as one remembers to top up the battery every 6 to 8 weeks to keep the charge above critical levels. There are now some batteries on the market that have a sleep mode, and disconnect from the BMS after a few hours of non use. These batteries can last all year on a single charge.

 

All the best

 

David

LiFePO4 can be charged to a slightly higher voltage, but all your chargers are the same voltage and current, which is safe for the batteries you have, so I'd be happy to use any one of them for all three batteries; however, chargers are probably the most unreliable part of electric bike systems, so it might be a good idea to take two. You'd be gutted if your one charger packed up on the first day.

Hi Emo,

 

You are correct, there is no longer any need to put the battery through any charge discharge cycles now. The latest lithium batteries dont need this kind of conditioning, however they will improve a little over the first few uses.

 

 

 

 

I have just looked at the latest 2014 Kalkhoff Agattu Impulse manual and it says to run down battery 3 times initially to get best use. Comments anyone?

Flecc said that as well I recall. But I have just looked at the latest 2014 manual for the Kalkh0ff Agattu Impulse and is says that the battery should be discharged fully the first three time to get best long term performance.

Comments please

You do need to do at least one conditioning cycle on the Kalkhoff batteries David, but that's for the battery meter. This one has a sophisticated meter which needs to have an accurate zero charge point to register correctly both the charge content, and the capacity when testing the latter. Hardly any other e-bikes have this metering. The emptying doesn't have to be one trip, it can be two or to more to reach empty.

 

So ride the bike to as near to empty as you can and then recharge. It's fairly easy to determine when the very near empty point is reached on these since the power drops to a very low level with still a mile or so left.

 

The meter zero can drift out over time, so if you suspect that has happened the conditioning cycle can be repeated then to reset the meter to accuracy. However, don't do this in cold winter weather since reading low then can just be the effect of the cold on the battery.

 

The quality of the cells in the Kalkhoff-BMZ and Panasonic batteries used on these bikes means repeated conditioning at first or subsequently isn't really necessary. It's a left-over idea from the earlier days of lithium batteries when the cell content did not have the consistency of today.

I keep reading to not discharge the battery over 80%, but the same goes for charging. Lithium batterie do not like being CLOSE to the maximum.

 

So to have a long life battery, and much more than the ones in the specs, what you should do:

- Do not charge over 4.1V/cell (increase by 15% battery life cycle in my experiences). I charge mine to 4V

- Do not discharge over 3.6V/cell

- Keep below 25 Celcius

- Charge at 0.2C (increase by 15% battery life cycle in my experiences)

- Continuous discharge at 50% manufacturer advertised C rate.

 

 

And you should have long happy battery to keep for YEARS!

That is not good advice for the Kalkhoff batteries through cwah. My post above explains why.

there may be justification for discharging completely at least once when the battery is new or if you want to 'reset' your battery. Quite often, batteries run at nearly full. One electrode is full of Lithium, the other is mostly empty. Flattening the battery give you two bits of information: low voltage cutout is working properly and known capacity when the battery is recharged back to full. The action can also benefit the electrodes, makes all that Lithium move from one electrode to the other and back again. Kind of giving them a gentle excercise.

I discharge my battery with 3 x 12V 50W halogen bulbs wired in series and use an energy meter to check the battery capacity when recharging. The discharge current 3-5A, the charge current is 2A.

Flecc, I understood it would be to reset the battery meter?

 

Still not good for battery but it has to be done! Like when I receive my battery new and I'm testing its capacity

That's right cwah.

 

However, I doubt if trying not to discharge fully matters any more with good quality cells. Older Kalkhoffs which have had a number of conditioning resets are now in their fifth year or more of battery life. Tillson's oldest battery for example still has most of its original capacity at that age despite him doing resets at various times. Few e-bike batteries achieve that.

I think it does. I've tested various latest cells and the trends now seems to increase battery capacity and lower cycle life. Many new top notch cells are specified for 300 cycles to 70% capacity. Or 500 cycles at best.

 

Amongst them you have the Panasonic NCR range, LG ICR range, INR type and more.

 

It's really up to the BMS to manage the cells and make sure they are not charged to maximum. And also to user to be careful about it.

 

 

Of course, 1 or even 10 reset on a battery lifetime won't have much effect on a 300 cycles battery. And doing full discharge or meter reset from time to time is of course a good thing to do.

Of course, 1 or even 10 reset on a battery lifetime won't have much effect on a 300 cycles battery. And doing full discharge or meter reset from time to time is of course a good thing to do.

 

True.

 

Don't forget that the number of cycles possible is greatly increased when used with the most sophisticated systems though. The Kalkhoff batteries are specified for 1100 charge cycles and the users I mentioned are far beyond 300 or 500 charges since 2007/2008.

 

For them I doubt trying to do better than the bike's own careful battery management will achieve anything.

You do need to do at least one conditioning cycle on the Kalkhoff batteries David, but that's for the battery meter. This one has a sophisticated meter which needs to have an accurate zero charge point to register correctly both the charge content, and the capacity when testing the latter. Hardly any other e-bikes have this metering. The emptying doesn't have to be one trip, it can be two or to more to reach empty.

 

So ride the bike to as near to empty as you can and then recharge. It's fairly easy to determine when the very near empty point is reached on these since the power drops to a very low level with still a mile or so left.

 

The meter zero can drift out over time, so if you suspect that has happened the conditioning cycle can be repeated then to reset the meter to accuracy. However, don't do this in cold winter weather since reading low then can just be the effect of the cold on the battery.

 

The quality of the cells in the Kalkhoff-BMZ and Panasonic batteries used on these bikes means repeated conditioning at first or subsequently isn't really necessary. It's a left-over idea from the earlier days of lithium batteries when the cell content did not have the consistency of today.

 

Thank you Flecc. Concise and clear advice, as always.