I've been reading recently about lithium ion bike batteries having a shorter lifespan when they are being fully recharged every time we ride them. They are recommending not charging them above 80% and just topping them up to 100% just before taking the bike out. Presumably this is to limit the time that the battery is 100% charged.
This is not about battery balancing or longer term storage because those are different issues but its about our daily usage. Claims are being made of potentially doubling the battery lifespan by doing this. If any of this is true, considering the cost of replacement batteries,
This completely contradicts Rad Rover's instructions for 100% bike charging after every ride.
It seems like it would be a pain in the ass to try to manually limit recharging ones battery to 80% or less.
Has anybody here used a battery satiator for limiting the battery charging to 80%? and if so, which brand or type do you use? The ones I've looked at did not have the lead ends that are compatible with the Rad battery.
i've been using this $100 advanced 300w charger for the last 6 months with my radrunner 1. charger has adjustable amp charge rates (1 to 5 amps) and 80% / 90% / 100% adjustable charge limit -
https://lunacycle.com/luna-charger-48v-advanced-300w-ebike-charger/
you'll need to add your own xt60 to 5.5mm barrel style charge connector.
the charger seems to work quite well - would recommend!
That's a really nice charger, and now I know what I want for my next present. I'll take two!
I go by voltage (80% is 51.5 volts) since I still have the stock chargers, but I usually just plug in in the morning if I need the range. Dual batteries means I can go 60 to 90 miles on a charge, so I don't need to top up every time, but it would be nice to have the charge automated. Although it's not good to force the batteries to 100% all the time, I also don't like letting the batteries sit when they are almost empty.
another good charger option (when in stock) -
https://www.eco-ebike.com/collections/chargers/products/48v-advanced-300w-eco-charger-1-to-5a-80-90-100
this charger also has the adjustable amp charge rates (1 to 5 amps) and 80% / 90% / 100% adjustable charge limit.
again, you'll need to add your own xt60 to 5.5mm barrel style charge connector.
(i use the 52v model of this charger to charge my juiced hyperscorpion - would recommend)...
@ wkindred
That Luna charger is exactly what I was looking for. Just so I can find the right adapter for my battery, is the terminal end of the Luna charger a XT60 male or female fitting.
Thanks again.
Quote from: how on December 07, 2020, 07:03:01 PM
@ wkindred
That Luna charger is exactly what I was looking for. Just so I can find the right adapter for my battery, is the terminal end of the Luna charger a XT60 male or female fitting.
Thanks again.
The XT60 connector on the charger shown on the Luna website is male.
By the way, I just bought the Luna charger myself. I might need to make two adapters myself since Luna is out of stock. The Rad battery has a 5.5mm barrel connector, and my second battery has an XLR connector.
Quote from: how on December 07, 2020, 07:03:01 PM
@ wkindred
That Luna charger is exactly what I was looking for. Just so I can find the right adapter for my battery, is the terminal end of the Luna charger a XT60 male or female fitting.
Thanks again.
the charger comes with an additional xt60 connector to allow you to make your own charge adapter...
Quote from: Altema on December 07, 2020, 08:09:04 PM
Quote from: how on December 07, 2020, 07:03:01 PM
@ wkindred
That Luna charger is exactly what I was looking for. Just so I can find the right adapter for my battery, is the terminal end of the Luna charger a XT60 male or female fitting.
Thanks again.
The XT60 connector on the charger shown on the Luna website is male.
the charger has an xt60
female connector installed but comes with an additional male xt60 connector for fabricating your own charge adapter.
Quote from: wkindred on December 08, 2020, 06:53:02 AM
the charger has an xt60 female connector installed but comes with an additional male xt60 connector for fabricating your own charge adapter.
Ah, thanks for the correction. The website shows the male connector, without explaining that it is the extra.
Quote from: Altema on December 08, 2020, 08:52:14 AM
Quote from: wkindred on December 08, 2020, 06:53:02 AM
the charger has an xt60 female connector installed but comes with an additional male xt60 connector for fabricating your own charge adapter.
Ah, thanks for the correction. The website shows the male connector, without explaining that it is the extra.
you're welcome! wasn't sure myself so had to actually look at my charger.
Quote from: how on December 07, 2020, 07:03:01 PM
@ wkindred
That Luna charger is exactly what I was looking for. Just so I can find the right adapter for my battery, is the terminal end of the Luna charger a XT60 male or female fitting.
Thanks again.
the luna charger has an xt60
female connector installed but comes with an additional male xt60 connector for fabricating your own charge adapter.
E bay ordered the female xt60 connected with 14 gu wire to a male 5.5 connector for $8.49 (Canadian & delivery included) about 10 minutes before I saw your last post....sigh.
It will be nice to finally just plug the battery into a Luna charger and have it automatically shut off at 80% full without me having to continually guesstimate approximate charging times after each ride..
Quote from: how on December 08, 2020, 10:19:00 AM
E bay ordered the female xt60 connected with 14 gu wire to a male 5.5 connector for $8.49 (Canadian & delivery included) about 10 minutes before I saw your last post....sigh.
It will be nice to finally just plug the battery into a Luna charger and have it automatically shut off at 80% full without me having to continually guesstimate approximate charging times after each ride..
They should allow for return in exchange for the right one. If not, let me know and I'll buy it from you. I have a dozen XT connectors in my drawer and can just solder the correct one on.
My Luna charger arrived a couple days ago, but I just got around to making the adapter last night. The charger works very well, and since it stops charging automatically, I don't have to be overly concerned about when it finishes. I have two batteries, so I just made the adapter with an end to fit each one. I can only charge one battery at a time, which is a bit inconvenient, so I'll probably buy a second charger. It's not a big deal at the moment because rides in the winter are shorter, and I don't NEED 80 miles of range right now. I may just use the second battery, and save wear and tear on the more expensive Rad battery by leaving it at home. Photo of the adapter is below!
I agree with this 80% rule. It's also really good to use on your cell phones or any other lithium based energy storage solution.
I really need to buy one of these charges. Thank you for posting these.
Sent from my Pixel 3a using Tapatalk
I have been watching this thread and it struck a chord with me. I have a Tesla and it is only supposed to be charged to 80% unless I am going on a trip and need more range. So today I received my Lectric xp, I already have 3 Rads and finally got my oldest daughter interested in riding so I figured lets check out the Lectric.
It says basically what has been said on this thread, charge to 75% and top off either the night before or morning of rides. Keep it close to 75% for storage.
I am not sure why Rad has us topping off after every ride, but between my Tesla and now the Lectric XP saying not to keep fully charged I am going to stop charging them up after each ride.
Gary
Quote from: radrover4fun on December 31, 2020, 05:07:36 PM
I am not sure why Rad has us topping off after every ride, but between my Tesla and now the Lectric XP saying not to keep fully charged I am going to stop charging them up after each ride.
I think Rad's idea is that it will keep your bike ready to go all the time, and having a full charge gives a more favorable impression. Basically, Rad is putting perception above battery longevity.
I think there is good reason to use this 80% charge method. The Luna 48v advanced charger just arrived. After setting for 80%, 2A the charger charged to about 87% according to the volts, then went into this oscillation turn off 3-4 sec., turn on 3-4 sec., turn off 3-4 sec., turn on 3-4 sec., ..., can anyone confirm this is normal?
Seemed kind of weird to me! Thanks
Quote from: wkindred on January 04, 2021, 06:09:44 AM
Quote from: vudude on January 03, 2021, 01:42:39 AM
I think there is good reason to use this 80% charge method. The Luna 48v advanced charger just arrived. After setting for 80%, 2A the charger charged to about 87% according to the volts, then went into this oscillation turn off 3-4 sec., turn on 3-4 sec., turn off 3-4 sec., turn on 3-4 sec., ..., can anyone confirm this is normal?
Seemed kind of weird to me! Thanks
yes, the off / on cycle at the end of the charge is doing the final balancing of the cells in the pack. quite normal...
That particular on/off cycle, with the Luna charger on the Rad battery, is because the BCM (battery control module) of the Rad battery does not give back an accurate voltage reading unless current is flowing into it. It's a protective design, and Luna Cycle tech support informed me that the Rad battery key switch needs to be in the "On" position. So that's what I do now, and the charger just stops charging when it's done and stays that way without cycling.
Quote from: Altema on January 06, 2021, 12:10:10 PM
Quote from: wkindred on January 04, 2021, 06:09:44 AM
Quote from: vudude on January 03, 2021, 01:42:39 AM
I think there is good reason to use this 80% charge method. The Luna 48v advanced charger just arrived. After setting for 80%, 2A the charger charged to about 87% according to the volts, then went into this oscillation turn off 3-4 sec., turn on 3-4 sec., turn off 3-4 sec., turn on 3-4 sec., ..., can anyone confirm this is normal?
Seemed kind of weird to me! Thanks
yes, the off / on cycle at the end of the charge is doing the final balancing of the cells in the pack. quite normal...
That particular on/off cycle, with the Luna charger on the Rad battery, is because the BCM (battery control module) of the Rad battery does not give back an accurate voltage reading unless current is flowing into it. It's a protective design, and Luna Cycle tech support informed me that the Rad battery key switch needs to be in the "On" position. So that's what I do now, and the charger just stops charging when it's done and stays that way without cycling.
wish the luna cycle tech would have told me the same when i inquired several months ago... :(
Thanks guys, good tip Altema. I'll turn the key to on next time.
Quote from: wkindred on January 06, 2021, 12:56:45 PM
wish the luna cycle tech would have told me the same when i inquired several months ago... :(
That would have been nice :-[
Perhaps they weren't aware of it back then, or at least that tech wasn't.
Quote from: Altema on January 06, 2021, 12:10:10 PM
Quote from: wkindred on January 04, 2021, 06:09:44 AM
Quote from: vudude on January 03, 2021, 01:42:39 AM
I think there is good reason to use this 80% charge method. The Luna 48v advanced charger just arrived. After setting for 80%, 2A the charger charged to about 87% according to the volts, then went into this oscillation turn off 3-4 sec., turn on 3-4 sec., turn off 3-4 sec., turn on 3-4 sec., ..., can anyone confirm this is normal?
Seemed kind of weird to me! Thanks
yes, the off / on cycle at the end of the charge is doing the final balancing of the cells in the pack. quite normal...
That particular on/off cycle, with the Luna charger on the Rad battery, is because the BCM (battery control module) of the Rad battery does not give back an accurate voltage reading unless current is flowing into it. It's a protective design, and Luna Cycle tech support informed me that the Rad battery key switch needs to be in the "On" position. So that's what I do now, and the charger just stops charging when it's done and stays that way without cycling.
I'm having this issue with the charger cycling on/off after reaching 80% even with the battery key switch in the "On" position. I have a RadCity Step-Thru 3 purchased in Sept. 2020. The original controller went out and the support person said the corresponding control wasn't available and sent a different one that's compatible (referred to as 'Controller 2020 - City HS' in the order). The controller works fine for the bike, but I wonder if it's the reason the charger is cycling.
Quote from: galvitron on February 05, 2021, 03:49:36 PM
Quote from: Altema on January 06, 2021, 12:10:10 PM
Quote from: wkindred on January 04, 2021, 06:09:44 AM
Quote from: vudude on January 03, 2021, 01:42:39 AM
I think there is good reason to use this 80% charge method. The Luna 48v advanced charger just arrived. After setting for 80%, 2A the charger charged to about 87% according to the volts, then went into this oscillation turn off 3-4 sec., turn on 3-4 sec., turn off 3-4 sec., turn on 3-4 sec., ..., can anyone confirm this is normal?
Seemed kind of weird to me! Thanks
yes, the off / on cycle at the end of the charge is doing the final balancing of the cells in the pack. quite normal...
That particular on/off cycle, with the Luna charger on the Rad battery, is because the BCM (battery control module) of the Rad battery does not give back an accurate voltage reading unless current is flowing into it. It's a protective design, and Luna Cycle tech support informed me that the Rad battery key switch needs to be in the "On" position. So that's what I do now, and the charger just stops charging when it's done and stays that way without cycling.
I'm having this issue with the charger cycling on/off after reaching 80% even with the battery key switch in the "On" position. I have a RadCity Step-Thru 3 purchased in Sept. 2020. The original controller went out and the support person said the corresponding control wasn't available and sent a different one that's compatible (referred to as 'Controller 2020 - City HS' in the order). The controller works fine for the bike, but I wonder if it's the reason the charger is cycling.
I assume the original Rad battery charger works fine, and the only issue is with the Luna Cycle charger. You can eliminate the controller affecting the Luna charger by removing the battery from the bike, turning the battery on, and trying the charger. If the charger operates normally, then the controller may indeed be the cause. If the Luna charger is still acting up, I would contact Luna Cycle and make it clear it does it with the battery turned on.
Quote from: Altema on February 05, 2021, 04:28:10 PM
Quote from: galvitron on February 05, 2021, 03:49:36 PM
Quote from: Altema on January 06, 2021, 12:10:10 PM
Quote from: wkindred on January 04, 2021, 06:09:44 AM
Quote from: vudude on January 03, 2021, 01:42:39 AM
I think there is good reason to use this 80% charge method. The Luna 48v advanced charger just arrived. After setting for 80%, 2A the charger charged to about 87% according to the volts, then went into this oscillation turn off 3-4 sec., turn on 3-4 sec., turn off 3-4 sec., turn on 3-4 sec., ..., can anyone confirm this is normal?
Seemed kind of weird to me! Thanks
yes, the off / on cycle at the end of the charge is doing the final balancing of the cells in the pack. quite normal...
That particular on/off cycle, with the Luna charger on the Rad battery, is because the BCM (battery control module) of the Rad battery does not give back an accurate voltage reading unless current is flowing into it. It's a protective design, and Luna Cycle tech support informed me that the Rad battery key switch needs to be in the "On" position. So that's what I do now, and the charger just stops charging when it's done and stays that way without cycling.
I'm having this issue with the charger cycling on/off after reaching 80% even with the battery key switch in the "On" position. I have a RadCity Step-Thru 3 purchased in Sept. 2020. The original controller went out and the support person said the corresponding control wasn't available and sent a different one that's compatible (referred to as 'Controller 2020 - City HS' in the order). The controller works fine for the bike, but I wonder if it's the reason the charger is cycling.
I assume the original Rad battery charger works fine, and the only issue is with the Luna Cycle charger. You can eliminate the controller affecting the Luna charger by removing the battery from the bike, turning the battery on, and trying the charger. If the charger operates normally, then the controller may indeed be the cause. If the Luna charger is still acting up, I would contact Luna Cycle and make it clear it does it with the battery turned on.
Yes, the original Rad charger works fine. I tried charging to 80% with the battery removed and the Luna charger still cycles on and off with the voltage on the Luna display going from 52.8 V to 36.5 V. So the controller is off the hook. Measuring the battery directly with a voltmeter reads 41.7 V. The 52.8 V value must be correct because the bike display shows full bars, but why would the battery read the lower voltage even with the key in the 'on' position? Maybe it's a feature of the BMS? I'm hesitant to reach out to Luna because it seems like the Luna charger is working correctly, but keeps getting turned back on because of the lower (incorrect) voltage reading.
Ok, controller ruled out 😊
Where were you measuring the battery voltage from with the meter, from the charge port or the two outer pins from the connector on the battery? A 48 volt battery at 100% is 54.6 volts, but the Rad charger usually gets the battery up to 54.4 - ish.
Charge the battery up with the Rad charger until the green light comes on, disconnect the charger, then measure the battery voltage at the terminals after 15 minutes. If it measures low, below 50 volts, then your battery may be bad. If the Battery voltage measures full, between 53.8 and 54.6 volts, then contact Luna about a possible problem with the charger. They will probably walk you through a few tests.
What an interesting topic.
So if you turn the key on and the charger works that means that there is no BMS when the battery is turned on and the BMS for the most part is regulated by the controller of the bike.
Have you been able to take a voltage reading from the charge port and not from the lower terminals of the battery? Is there a difference?
I'm not so sure it would be safe to charge the battery with the key in the on position if it really is bypassing the BMS. I realize the charger is fairly smart but it's better to have two safety checks hence the BMS and the charger and the BMS in the battery.
How many other people who own the Luna charger are having this kind of problem?
Sent from my Pixel 3a using Tapatalk
Quote from: Veggyhed on February 10, 2021, 07:32:17 AM
What an interesting topic.
So if you turn the key on and the charger works that means that there is no BMS when the battery is turned on and the BMS for the most part is regulated by the controller of the bike.
Have you been able to take a voltage reading from the charge port and not from the lower terminals of the battery? Is there a difference?
I'm not so sure it would be safe to charge the battery with the key in the on position if it really is bypassing the BMS. I realize the charger is fairly smart but it's better to have two safety checks hence the BMS and the charger and the BMS in the battery.
How many other people who own the Luna charger are having this kind of problem?
Sent from my Pixel 3a using Tapatalk
I would have to take a Rad battery apart to confirm, but I believe the BMS does not get bypassed with the key on. The battery voltage measures differently at the charge port than it does at the output terminals when the key is off, and they measure the same when the key is on. Maybe some sort of extra protection circuit before the BMS? I'm just guessing about the BMS at the point, but the tests should be valid.
Well that's interesting. I wonder if it has to do with the circuitry that allows for battery charge level on the battery itself. The small LED display at the top of the battery because the key has to be in a set position for the LEDs to display the charge on the battery.
Sent from my Pixel 3a using Tapatalk
I have been measuring the voltage at the charge port. I didn't think of the lower terminals which are much easier to get the voltmeter leads on! I don't have the RAD charger available at the moment (currently at my office) so I ran the test using the Luna charger- I may repeat RAD charger later.
I charged to both 80% and later 100% and after letting the battery rest for 15 minutes, measured the voltage at each location with the key in each position. Here are the results..
80% charge, key in 'off' position:
Luna display=52.8V
Charge port=29.6V
Lower terminals=27.9V
80% charge, key in 'on' position:
Luna display=52.8V
Charge port=41.4V
Lower terminals=51.7V
100% charge, key in 'off' position:
Luna display=54.6V
Charge port=31.2V
Lower terminals=29.4V
100% charge, key in 'on' position:
Luna display 54.6V
Charge port=43.4V
Lower terminals=53.9V
Conclusion: In each case the voltage reading at the charge port is lower which I assume is causing the Luna charger to cycle on and off regardless of key position. I wonder if these voltages are typical, especially for folks who had success charging with the key in the 'on' position.
It does appear there is some other circuitry that causes the voltage to read lower than the actual battery voltage at each location (especially at the charge port).
The battery performance seems fine, but perhaps a load test would give more information. Maybe time to reach out to Luna.
Thanks for putting the time in for testing. I knew it had to be some sort of issue with additional circuitry. However looking at those numbers that's kind of crazy and they're all over the place.
Sent from my Pixel 3a using Tapatalk
The Rad battery charge port is connected to the battery through a semiconductor switch turned on by the Rad BMS. If the BMS is not seeing charge voltage at the charge port, it won't turn on the charge switch. The low voltage that you're seeing is due to leakage current. ("Leakage" in this context is an electrical term and not a description of a defect.) If you put just a bit of resistance across the charge port terminals, you'll see the voltage drop dramatically, because there is insufficient current to support it.
When the key switch is turned on, the BMS turns on the discharge semiconductor switch, which supplies power to the battery connector and the LED battery pack meter.
The key switch does not directly make or break a connection to the battery; the semiconductor switches do that. The key switch signals the BMS.
More information on the Rad BMS:
https://www.radowners.com/index.php?topic=1025.0
I've been doing further reverse engineering of the Rad battery, and I have a correction to make to one of my earlier statements. The Rad battery charge port is connected to the battery through a semiconductor switch (a MOSFET) as I stated, but I do not believe that the switch is controlled by the BMS chip. (For complete reverse engineering, I need access to the bottom circuit board layer, and for that I would need to disassemble my only Rad battery, which I am not about to do.) It is turned on when a live charger is connected to the charge port, which I suspect is enabled by additional circuitry outside of the BMS chip.
The BMS chip is always powered on. With no activity, it is in a "sleep" mode drawing very little current. But the BMS is always active.
Notice that the Rad battery charge circuit has protection diodes, which prevent current from flowing out of the battery into the charger. Luna's concern about inrush current from battery to charger if the battery is plugged in before the charger does not apply to the Rad battery. I called Luna out on this, when they incorrectly advised a Rad owner, and got this response:
"Okay well that's how our chargers are. I was answering the question based on products we sell."
Apparently, Luna is only guessing how the Rad system works.
(If I were designing the Luna charger and were concerned about inrush current, I would include protection diodes in the charger.)
A very small amount of leakage current can flow in the reverse direction through the diodes and charge MOSFET, which is why you can see a voltage at the charge port. The voltage that you see will depend upon the input impedance of your multimeter. If you place a resistor across the charge port terminals, even a relatively high resistance, you will see the charge port voltage drop because of the tiny reverse current flow. The bottom line is that you cannot use the Rad charge port to read battery voltage with a multimeter unless the MOSFET is active and charge current is flowing.
The power MOSFETs, which supply power to the motor controller port, are only turned on when the key switch is turned on. This changes the leakage current situation, hence the change in voltage seen at the charge port with your multimeter. Some Rad models support regenerative breaking - in that case, the batteries would be charged through the motor controller port and not through the Rad charge port circuitry.
The Rad charger never disables current to the battery. The Rad charge LED turns green when current out of the charger drops below about 200 mA, but current still flows. I have seen 3 mA flowing even after many hours. I suspect this current is necessary to allow the BMS chip to balance the pack, which is why Rad advises leaving the charger connected for 12 hours periodically to balance the pack. If the Luna charger shuts off current to the battery when it indicates charge complete, battery balancing may not be taking place. I would be interested to know if the Luna charger does or does not continue to supply this apparently necessary small current on charge complete.