should i buy a smarter charger??

vincent

Well-Known Member
read a lot on here about how it is better to only charge to 80%....

just bought a easymotion street and have 2 other ebikes
wondering if i should invest in an advanced charger to help long term battery life?

if so what options are there
thanks for any help
 

rick-n-ns

Member
I have a few thoughts on this "theory".

If the point of charging to only 80% is to get a few more cycles, OK lets say for a moment that it does work, and you get 20% more cycles with the same amount of capacity remaining after say 800/1000 cycles, I say what's the point ? You no doubt got less total miles out of the battery only charged to 80%, because the "top" part of the battery is by far the most powerful, and the bottom part of the battery the weakest, and quite prone to voltage sag under load.

The manufactures all seem to agree that charging individual cells to 4.2 is perfectly fine. What "some guys" think, and gets repeated over, and over the internet don't interest me too much

I also wonder if these smart chargers also balance the cells at a lower voltage or just shut off at some predetermined voltage. Myself I'd prefer to have my cells balanced at least every 2nd or 3rd charge. I know my "cheap" charger takes about an hour to do this, the battery is up to full voltage long before the light turns green.

On top of that most of my rides have averaged 30 miles, and I want/need all my battery.

It is a good idea not to charge to full, and leave in that state. I like to top it up as close to ride time as possible.

Luna cycle sells a charger for 48 V systems that will charge to 80, 90, or 100% and is reasonably priced. The cycle satiator, which I don't think is quite ready for sale just yet. It is priced at about the same as a new battery ? Hardly worth it, IMO except for the fact it is adjustable, and could charge batteries of different voltages.

I guess having said all that if you know your only going for a shorter ride there is no need to "fill it up"
 

vincent

Well-Known Member
excellent points

not sure what to think about all this, even in the summer think the bike wont sit more than a couple of weeks with a full charge, these bikes are all stored in the house at 80-85 degrees

the problem with attempting to tell when you hit 80% with the regular chargers is how would you do it
mine are either red or green

dont have the easy motion yet so maybe it is different

and i agree that in the long run it may not be worth it


i never have battery issues with my ipads, cell phones, rechargeable headlamps, flashlights etc and i do all of them to full or green light
i do try not to run stuff way down though

it seems the stock chargers would be cutting off early or slowing down at the end if it is good for the batteries, but maybe they are not smart enough to do that yet

guess we will know more on all this in 5-7 years.....
 

Adrian

Active Member
There has been a lot of discussion and study of this. How you charge and discharge your battery packs can and will have an impact on its longevity and performance. You can do a search over on endless-sphere and spend a couple of days reading if you want.

Here are the cliff notes as I see them;

1) if you want to increase usable longevity (people talk of 1000's more cycles in ideal situations) only charge to 80% capacity and discharge to 20%.

2) Buy a battery with more capacity than you need; doing 1) is then not an issue.

3) The slower you charge the better, so use a charger with less amps or is adjustable - if time is not an issue, use a 1amp charger.

4) Discharge as slow as possible - the more amps you pull from your pack the harder it is on the cells - constantly drawing 25amps because you are in the wrong gear of a mid drive will reduce longevity much more than pulling 10-15 amps and peaking now and then).

5) Generally, a 1 amp charger will charge a 10ah battery to full charge in 10 hours. A 2 amp charger will do it in 5 hours. If you have a dumb charger, you can use a timer on the socket to approximate an 80% charge.

6) Packs don't usually balance their cells until they get to 100% charge so need a full charge periodically.

7) a bunch of other stuff I don't have time to write as I've got to get to work. ;)
 

vincent

Well-Known Member
thanks adrian

if someone chimes in on a smart charger that would do both my 48 volt and 36 volt batteries i would be interested

i am a casual rider and the bike taking 10 hours to charge will rarely be a big deal


using a timer only works if you really know where your charge is etc, which maybe with the easy motion i will

but the other 2 just have 3 led lights...

dont think riding wise i am hard on the batteries, am using the gears but definitely will have to learn more with the em street, it has more gears than i am used to and will keep that in mind about the not using the wrong gear and overworking the battery- thanks for that tip

even on the cemoto and older mariner i never make much of a dent if any going 10-15 miles on the battery lights , the em should be even better i think so rarely will run the battery below 20% before charging, that objective is pretty doable
and charging to 100% sometimes should be easy too

thanks for all the suggestions, will check out chargers on endless sphere and luna cycles now
 

vincent

Well-Known Member
did some reading and the chargers at luna cycle are all pretty cheap

i have no idea which chargers to even look at to work with my bikes

and thinking the em street being under warranty i probably am not allowed to use a different charger with it anyway.
 

Adrian

Active Member
I recently bought the new 52V Luna smart charger (new as in it's a 220V rated power supply for Europe) and it allows 80% or 100% charging at 1,2 3, 4 and 5 amps. It's nice but a little noisy compared to a fanless charger - though not as noisy as some fan chargers I've heard.

It's $100. They do a variety and you need 1 per voltage - so, if you have 48v and 36v batteries that's 2 chargers (the 36 and 48v are the original designed Luna chargers AFAIK and allow charging to 80, 90 ad 100% at 2 and 5 amps - that may change to be like the 52v later).

You may need an adapter for your different batteries - I needed a 4.5mm barrel adapter for my shark pack.

However, if I needed 2 chargers @ $200 I would rather go for a new Cycle Satiator charger that can do both. It's a bit more expensive but it's fully programmable and will cover everything. http://www.ebikes.ca/product-info/cycle-satiator.html

Always keep a spare cheap/dumb charger though - chargers are probably the least reliable ebike electrical component you can buy.
 

Adrian

Active Member
I have a few thoughts on this "theory".

f the point of charging to only 80% is to get a few more cycles, OK lets say for a moment that it does work

Actually, battery life cycle is quite well understood. However, the reason why it seems vague and why it's difficult to get a hard and fast, "how long will my battery last/how many cycles will I get" is because of the many different variables such as how fast you charge, how deeply you charge, how fast you discharge, how hot/cold it is, what cell chemistry you have, etc, etc, etc.

But, the difference between worse case use and best case use can literally be 1000's of charge cycles. That is not pie in the sky. There is hard data out there showing this if you'd like to go and find it.

Now, there are factors which are not easy to account or adjust for; if you live in a hilly area, generally, you are going to draw more amps, more often than someone living in the Netherlands so your battery will suffer more. If your commute is really long, you will by necessity discharge your battery deeper than someone with the same battery size on a short commute (assuming both charge daily).

However, the 80/20% charging rule is one of the things you can usually control and it can make the biggest difference to usable longevity for the least amount of effort/money.

Of course, there is something else to consider; battery technology is improving in leaps and bounds. In 2 years time, there may be cells that are 2x the capacity with 2x the life expectancy so unless you can't afford to replace your battery every 2/3 years with better tech, perhaps you shouldn't worry too much. :D
 

Adrian

Active Member
BTW, you can use a multimeter to figure out how much charge your battery has.

Here's a thread on endless sphere though there are many others I'm sure; https://endless-sphere.com/forums/viewtopic.php?f=14&t=74465

For a 52V 14s4p Lithium Ion battery, full is 58.8v, 80% is about 55v, 50% is 51.8v and 49v is 15% (numbers taken from a post on the electricbike.com forum).

Can't remember what 48v and 36V are but the numbers are out there if you google.

You can also wire in meters that will do the same though are a little more sophisticated; http://lunacycle.com/gauge/
 

vincent

Well-Known Member
lol adrian, all very interesting stuff

might buy that satiator charger, that is what i was looking for and it seems a good idea to have a back up charger anyway
it looks like it is out of stock right now

just found a thread on the easy motion forum saying it does not have an adapter for em, those guys were cutting up their cords
i will contact grin and see what they offer now, the thread was old

hoping ravi will chime in at some point and see if using this would void the warranty..
if he doesnt in the next little while i will email him direct, sure he is busy

thanks for all this info
 

vincent

Well-Known Member
guessing the em display does not do any of this? but thought there was a battery percentage on it, does this change as the bike is being charged? seems like that would work- i dont have my bike yet


and again not sure if paying someone to wire in something like the gauge or maybe that cycle analyst- if it will do the correct gauges- would mess up the warranty...
 

Adrian

Active Member
Yeah, I wish I'd bought a satiator now too to be honest. Adapters may be an issue but there are usually good posts around by people who have made their own (it's usually not rocket science anyway).
 

Adrian

Active Member
guessing the em display does not do any of this? but thought there was a battery percentage on it, does this change as the bike is being charged? seems like that would work- i dont have my bike yet


and again not sure if paying someone to wire in something like the gauge or maybe that cycle analyst- if it will do the correct gauges- would mess up the warranty...

The cycle analyst is overkill for you I think but there are more simple meters that will do the job. You may void your warranty for sure so check first.

A multimeter that you can use on your battery will give a more accurate reading than a 3/4 light display - not useful for riding but, for charging, it will be useful to know where you're at then you could, in theory, figure out where 80% is from there and time your charge based on your standard charger amperage (oi, long sentence ;) ) Might be a PITA until you've figured it out but then it would be routine.
 

George S.

Well-Known Member
Yeah, a multimeter works pretty well once the riding is done and the battery has rested a bit. I'm annoyed with this voltage stuff, since I have a 36v charger, a 48v charger, and a 52v charger. I'd like to see a charger that covered all three with a 1-5 amp rate (charge rate) and an 80% charge setting.

I guess cutting off the 'right' ends is the last option, if they go full 'proprietary' on you. You can still put standard connectors on the connector you cut off.

A lot depends on how hard you work your packs. If you run them daily and fairly hard, the 80% charge should pay off in the first year, but you need a big battery to do that and have some reserve.

I think Luna has shaken up the ebike market for batteries. They sell big batteries. They have the best performance cells around. They have decent prices. The more people push the speed the more they will go down the road DIY has gone down, bigger packs and high discharge rate cells. It becomes an issue of watt hours to the LVC.
 

rick-n-ns

Member
There has been a lot of discussion and study of this. How you charge and discharge your battery packs can and will have an impact on its longevity and performance. You can do a search over on endless-sphere and spend a couple of days reading if you want.

Here are the cliff notes as I see them;

1) if you want to increase usable longevity (people talk of 1000's more cycles in ideal situations) only charge to 80% capacity and discharge to 20%.


4) Discharge as slow as possible - the more amps you pull from your pack the harder it is on the cells - constantly drawing 25amps because you are in the wrong gear of a mid drive will reduce longevity much more than pulling 10-15 amps and peaking now and then).

. ;)

If you only charge your battery to half it's capacity, then you "should" get twice the cycles, but your going half as many miles per charge, so in the end either way will take you the same (approximately) amount of mile per battery life cycle, again I ask whats the point ?

The three major manufactures who designed, and build the batteries in the first place I'm sure have a clue, and all agree that 4.2 V per cell is fine.

I saw one of those charts too, but was in an ad for one of those $300.00 chargers. ? For the record my cheap charger seems to top off at 4.16 V/cell which is about 95% so I'm not at all concerned about it. I expect 4-5 years out of it. Like another said we will know more in that time.

I totally agree with your #4 statement. A person who got a bike for commuting, and drives wide open all the time is not going to get the life out of a battery as someone who uses it more moderately like at 1C or less discharge.

"Actually, battery life cycle is quite well understood."

Since the newest cells have only been out for about a year, I don't know how anyone would have concrete evidence how they behave after 1000-2000 cycles. Except for the manufactures.

I bought a digital volt meter before my bike arrived, everyone should have one.
I have been to ES lots, and am a member there with the same user ID.
 

Donny

Active Member
Another thought is just to do what the manufacturer of your particular bike and/or battery says to do. I get the obsession over this - to a certain point. I know these things aren't cheap and I'm financially challenged as it is so I should probably care more about this than I do. However, I'm simply doing what the manufacturer says to do with mine. I'm not going to go out and spend even more money on smart chargers and all of the rest of it trying to squeeze a bit more out of it. I love the technology and everything that goes along with these things, but I will not let myself get drawn into being this paranoid over my battery pack. While we're talking about it though - has anyone had theirs long enough to actually observe a failure as it related to time and/or charging cycles?
 

Adrian

Active Member
If you only charge your battery to half it's capacity, then you "should" get twice the cycles

No, it's not that simple. 80/20 is not half (it's actually 60% ;) ) and 400 vs 1600 (is an example I've seen) is more than twice the cycles.

As I've said, for some, the 80/20 rule is a simple one for some to follow, especially with a smart charger, that can extend the usable life of a battery by quite some.

As chargers tend to be relatively unreliable, I'd advise everyone to have a spare - and if you're going to get a spare, just pay extra to get a smart charger while you're at it.

Fwiw, I hammered my last pack with high performance 25r cells, charging it to full every day - 18 months later, I didn't trust it to do more than one way of a 16km round trip.
 

NoDTMF

Active Member
If you have a hybrid car, and connect a obdII scanner/monitor you can see the state of battery charge continuosly, My Ford Escape keeps the batteries between 40-70 percent. Then every once and a while it goes down to 20 and up to 80. After 6 years I still get the same gas mileage, so the batteries are still doing their job.