I'm toying with the thought of building a rechargeable battery system, using a number of cheap Li-Ion and NIMH battery chargers, controlled by a timer to keep the batteries ready to use, while preserving their maximum life cycle.
For this purpose I collected some data:
1) Li-Ion batteries like frequent charging to 60%, whereas 100% charging shortens their lifespan.
2) Best is a separate, slow charging charging circuit for each battery.
It would be useful having four batteries of each type at any time ready for use and welcome any suggestions on this idea...
Regards and Thx in advance, Joh 🙂
For this purpose I collected some data:
1) Li-Ion batteries like frequent charging to 60%, whereas 100% charging shortens their lifespan.
2) Best is a separate, slow charging charging circuit for each battery.
It would be useful having four batteries of each type at any time ready for use and welcome any suggestions on this idea...
Regards and Thx in advance, Joh 🙂
Li-Ion batteries are used in cell phones,most of which are charged to 100% every night. My cell phones with Li-Ion cells have worked more reliably than older NiMh driven ones. I would be interested in the rational to only charge a LI-Ion battery to 60%
li-ion charging is quite different from Ni-Cad charging.
A trickle charger works for Ni-Cad and lead acid, but not for li-ion
Continuous charging of Li-ion will damage them.
A trickle charger works for Ni-Cad and lead acid, but not for li-ion
Continuous charging of Li-ion will damage them.
Jaclement the life of a Li-ion is extremly dependent on the voltage in the cell.
The chemistry in it causes it to slowly self destruct and the higher the voltage the
faster this happens. At a full charge this can show a decrease in cell capacity in
just a few months. But if the cell isn't exposed to as high a voltage say a 85% charge
this decrease in capacity is a lot slower and down at a 60% charge this chemical reaction responsible for the cell losing capacity just about stops. This is why when you get anything that's powered with a Li-ion batery it always says charge before using they ship it only partialy charged to extend it's shelf life.
The chemistry in it causes it to slowly self destruct and the higher the voltage the
faster this happens. At a full charge this can show a decrease in cell capacity in
just a few months. But if the cell isn't exposed to as high a voltage say a 85% charge
this decrease in capacity is a lot slower and down at a 60% charge this chemical reaction responsible for the cell losing capacity just about stops. This is why when you get anything that's powered with a Li-ion batery it always says charge before using they ship it only partialy charged to extend it's shelf life.
Yes that's right; it's, because of its chemistry. That's why I'm toying with the idea of creating charger bank of several cheap universal China chargers, which allow me to control its charging time via a timer.
Once the NIMH are fully charged and the Li-Ion to 60%, the timer charges each day only about 10 Min and so, keeping all batteries ready to use. That charger setup allows to have the four battery types always ready for use:
4 of 26650 Li-on // 4 of 16340 Li-Ion // 4 of AA NimH // 4 of AAA NimH
For that purpose I bought the following gear:
1 x battery capacity meter:
Li ion Battery Capacity Indicator Measurement Board for 5 Packs Cell 18V 21V | eBay
That allows me to monitor the Li-Ion charge to 60%
2 x battery chargers:
Charger Universal 18650 26650 AA Battery I4 4 Output Intelligent Li ion NiMH | eBay
LaGrosse quality charger: Battery Charger Review 2014 | Best Batteries Charger
- which helps me refreshing and charging older NimH and NiCad batteries.
I wished somebody would create such a universal charger utility. Even better, if the Li-Ion charger would automatically limit the charge to 60% and then maintain it at that level.
I also bought this thin 20A battery bank, which has an inbuilt battery capacity indicator: http://www.ebay.com/itm/Ultrathin-20000mAh-Portable-External-Battery-Charger-Power-Bank-for-Cell-Phone-/281391674367?pt=US_Cell_Phone_PDA_Chargers&var=&hash=item41844033ff
Li-ion are not compatible with trickle charging.
You can do this with lead acid and ni-cads, not with Li-ion.
That's right, too. That's why I fist charge the Li-Ions to 60% and the daily (every 3 day) 5-10Min. timer is going to keep them at 60%; i.e. to compensate the self discharge.
I wouldn't call that "trickle charging" do you?
Actually, I read that Li-Ion batteries prefer frequent recharging to 60% than to 100%.
The good thing is that I'm able to monitor the capacity charge level and set the timer accordingly.
I wouldn't call that "trickle charging" do you?
Actually, I read that Li-Ion batteries prefer frequent recharging to 60% than to 100%.
The good thing is that I'm able to monitor the capacity charge level and set the timer accordingly.
You just wasted your cash.
Lipo cells behaves much differently than other chemistry as for example SLA.
Ebike and voltage monitoring concept ? mini article created for young people
Well, it says "LI-Ion Battery Indicator". How else can I test the mAH capacity of an Li-Ion? So you think this one is "Scata?" 🙂
So you reckon this one will do (?): http://www.ebay.com/itm/LCD-Battery...31040559447?pt=AU_Gadgets&hash=item4d138e1157
So you reckon this one will do (?): http://www.ebay.com/itm/LCD-Battery...31040559447?pt=AU_Gadgets&hash=item4d138e1157
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Unfortunately all of them are as you did describe them 😉
The one that you got with the LED is over my ebike battery and totally unreliable regarding capacity when there is no action.
And also it is impossible for me to use it when driving.
http://www.ittsb.eu/forum/index.php?topic=959.0
The somewhat more reliable solution seems to be those meters which record voltage and ampere and calculating both as incoming Ampere hours.
They are advertized as solar watt meter.
If you have a 1000mA hour battery charged to 60% or 600mA hour what is your point? A typical modern battery should be able so cycle at least 80% of its capacity >300 times before showing sings deterioration. The battery world is not competing to make 1000mAh batteries that can store 2000mAh, they are trying to make it smaller and lighter.
Well, to test the tester... I could discharge the Li-Ion battery to 2V5 and then measure the mAH charging current. That might give me an idea how much 60% current has been digested. I might even allow it to charge to 65% of its nominal capacity and then see if the tester's LED comes on... or what else should I do?
A battery should be tested using a constant current discharge of three times it rated current. In other words if you want to see how good your 1000mAh battery is discharge it with 3000mA for a period of 15 seconds and the battery voltage should remain fixed for the 15 seconds.If you are testing deep cycle batteries then the period may be 20 hours and much smaller constant current load.
I have no problem with NimH and NiCad batteries. My question is how to measure the charging process to 60% of of a Li-Ion battery?
periodic re-charging is not trickle charging.
In that respect you are right.
But from what you were describing that was not the message as I understood it.
Well yes, let's move on. Since all capacity meters are unreliable, I still wonder how to find out when the Li-Ion battery is charged to 60% ??
The only way I can think of, would be (as mentioned) to first discharge the battery and then recharge it, while monitoring its charging current.
I then could set the timer accordingly and then I would need to monitor its self-discharge rate, in order to discover the correct timer setting, which keeps the battery topped up to 60%.
It would be great if there was a Li-Ion charger, which does it all automatically! Weird that Li-Ion charger manufacturers still don't offer them...
The only way I can think of, would be (as mentioned) to first discharge the battery and then recharge it, while monitoring its charging current.
I then could set the timer accordingly and then I would need to monitor its self-discharge rate, in order to discover the correct timer setting, which keeps the battery topped up to 60%.
It would be great if there was a Li-Ion charger, which does it all automatically! Weird that Li-Ion charger manufacturers still don't offer them...
The unreliability comes from the fact that they are plain voltage meters.
One laptop PC by using far complex components can offer an estimate that it battery is at 60% of remaining charge, because it battery management system ... is aware of the battery capacity, and because an internal timer has also measure all ready the duration of time which the specific battery has been used.
Therefore simple logic it would instruct us to remove 40% energy of a fully charged battery by a smart DC load, and then the battery is exactly where we need it to be for long term storage. 😉
...plain V meters. Yet, they might be useful once we gone through the (in my previous post) described process? It's, because there we can find out at which capacity level the LED starts to light up. That offers us at least some estimate...
Discharging from 100% is one way of getting down to the required 60%. Yet, how to monitor that? A PC program is great for PC batteries, but how to monitor a Li-Ion, type 26650 ??
Besides, I'm using Li-Ion batteries for my busking PA/(street performance) equipment. I happen to be a whistler musician. Chances are you audio fans might like what I do. Hear & watch me blowing up, here:
https://www.mediafire.com/?t0mocnkevh9bz1c
https://app.box.com/s/6f72eb90c2002db2e9fc
https://app.box.com/s/bluoxacemqlslhtq9bv9
https://app.box.com/s/3ahg6ytsixqnzxzluos4
http://www.youtube.com/watch?v=KPEW8KdBxds
Enjoy!
I'm also into philosophical pondering...
Discharging from 100% is one way of getting down to the required 60%. Yet, how to monitor that? A PC program is great for PC batteries, but how to monitor a Li-Ion, type 26650 ??
Besides, I'm using Li-Ion batteries for my busking PA/(street performance) equipment. I happen to be a whistler musician. Chances are you audio fans might like what I do. Hear & watch me blowing up, here:
https://www.mediafire.com/?t0mocnkevh9bz1c
https://app.box.com/s/6f72eb90c2002db2e9fc
https://app.box.com/s/bluoxacemqlslhtq9bv9
https://app.box.com/s/3ahg6ytsixqnzxzluos4
http://www.youtube.com/watch?v=KPEW8KdBxds
Enjoy!
I'm also into philosophical pondering...
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Possible, but ugly.
I think you need learning software to do a good job. Neural network. Estimate contents of battery at all times. Or maybe you can do this with Kalman filter?
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