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[vasculopath]

Hey all, been lurking a bit, learning a lot.  I bought an Ego RS used with ~500 miles a few months ago.  Love it.
I home charge but wanted to test range and local charge options.  Ran a ~60 mile loop on local roads, then sprinted up the freeway to test range.  I was planning on getting back home and near a public charger with ~10-15% left, but bike went into Limp mode at ~25% while on the freeway.  I was 5 miles from an exit, finally pulled off and bike went back into sport mode though it 'felt' like it was not at full power, just didn't have that zip.  Bike went in and out of limp as I made my way home.

Charged on my level 2, took over 6 hours, let it balance, and now seems normal. I have put ~500 miles on the bike since I've had it, usually re-charge at ~50% and always let it balance and finish.

is this common?  I feel like I should at least be ale to use ~90% of the battery and range without getting into such an issue.

Tom

[Specter]

Once you drop below 20 percent it will put you into I guess you could call it 'Rain Mode'.  It's very conservative on what it will allow you to do, your acceleration is limited but from what I have seen on my Ribelle, you can still get up to 80 MPH or more, just takes a bit to get up there, like maybe 15 seconds instead of maybe 3 or 4.

I think it's at 10 percent where it goes into a full limp, which I think is the eq of economy mode, it won't let you go past 45 or 50 mph etc.  THIS is to preserve your battery as long as it can to get you to somewhere to charge.  The bike can NOT read your mind, it does not know where you live, what your charge plan is, etc, so in it's mind, oh he's in trouble, he's at 10 percent and STILL running, lets stretch this out as long as we can for him to give him the most miles we can to go find a charger.

Aaron

[vasculopath]

I get that, and I'm fine with the bike going into that mode at say less than 10%, but this was closer to 25-30% initially, I think like ~29%ish.  The pic above was not when it initially kicked in.  I didn't want to pull over in case I was going to get stuck.  If it does it again I'll get a pic.  If this is normal behavior, that kinda takes the effective range for me down to less than 80 miles...

[jotjotde]

Just as an info: My bike went into limp mode at 3% SOC on two occasions.
BTW: After going to 0% SOC, the bike still runs. Probably not good for the battery, so I will not do that again.

[Stonewolf]

Did you charge it first or was this done on whatever charge it had already?

It may have been severely out of balance (which like, that's something you'd have to work really hard to do), I'd recommend putting it on AC charge and leaving it until it stops balancing then repeating the run.

The bike doesn't really go into any mode at low SoC, the BMS progressively limits power for battery protection, you just generally don't notice until it gets fairly low.

It *will* go into limp mode near 0 when you've basicly exhausted the usable battery capacity. It'll give you whatever it has left in the overhead but it doesn't know how much there is and can't tell you what you have left. How much you get out of that really depends on battery health and balance. On a recent trip I ended up a little over 10 miles short (thanks Chargeplace Scotland) and I got about a kWh into it, I was on something like -5%. Incidentally, DO NOT park it like that!

[vasculopath]

Did you charge it first or was this done on whatever charge it had already?

It may have been severely out of balance (which like, that's something you'd have to work really hard to do), I'd recommend putting it on AC charge and leaving it until it stops balancing then repeating the run.

The bike doesn't really go into any mode at low SoC, the BMS progressively limits power for battery protection, you just generally don't notice until it gets fairly low.

Left the house at full charge so that I could range test.  Had gone though a full charge form ~50% to balanced.  What you're describing as far as "mode" accurately explains how it was acting as it was going in and out of Limp.  Thanks.

[DonTom]

is this common?  I feel like I should at least be ale to use ~90% of the battery and range without getting into such an issue.Tom

Could your SOC need calibration? Perhaps you were really down at 1% SOC.


When my SS9- SOC  is out of calibration (as it is right now)  I get this on my screen:


-Don-  Reno, NV

[DonTom]

since I've had it, usually re-charge at ~50% and always let it balance and finish.

My own experience kinda shows that it is best to only charge when down well below 40% SOC. I realize this is not always possible, but when I charge up at a higher SOC is when I am much more likely to get the message as shown in my previous message. Anyway, a full charge all the way to 100% SOC from the limp mode should fix it. And from then on, only charge above 40% SOC when you must (to have the range to get to your next charger or stop).


And it is usually best to NOT always charge to full (above is an exception). What I do is normally stop at around 85% to 90%  SOC but once in a while I do a home charge to 100% SOC to help balance the cells. I try to only do my full charging at home. Slows down too much of the charge rate when on a trip. And it is hard on the battery to always charge it to full.


You can safely ignore the message that says it is best to not to stop the charge during the cell balance. In fact, on my road trips, that is when I usually stop the charge. But my typical home charge is to full, unless I won't be using the bike for a while, then I either put the bike in the LPR mode charging or else I leave it sit not charging and leave it at around 85% SOC.


-Don-  Reno, NV

[vasculopath]

So as a follow up, I went out to repeat the range test after a this past issue.  Bike had gotten as low as 6%, charged level 2 (Tesla charger 40A with Teslatap) to 100% and balanced.  Today, the bike gave me 130miles down to 3% and no LIMP mode, though the bike did go into "Sedate" mode at ~10%.  Could still break speed limits, but much softer power delivery.  I'm going to charge til ~80's routinely in the future and run it down lower more often and see how that goes

[Specter]

A general rule many like to follow is 20 - 85.  With an occasional run to full charge.

Going down to 20 percent isn't pushing the battery too hard, and is not engaging any 'soft' modes to protect the battery or get you home.

Going up to 85 percent, isn't pushing the battery charge wise, and keeps you out of the slower charging balancing mode as well.

This range works well for travelling as well as it allows you to basically get the 'fastest' speeds out of the CCS chargers you may encounter as well as the J chargers if you are stuck charging AC on the road.

id say once a week if you ride very often or once every few weeks, let it top off to keep the batteries balanced and in pristine condition.

Remember, the way to get more cycles out of a battery is to use it gentler, which means a bit more in the 'center' of the charge zone, ie 20 - 80   20 - 85 etc, and go easier on the discharge.  Given you are not racing the thing at 120 mph all the time, the batteries are not really being beat up, so that leaves you with narrowing the 'use range' when you can.

Ideally though, when you look at the guarantee for them, and the way Lith batteries work, you will put about 100k or so on the bike before you get to the end of their 'warranty' life.   1200 cycles.

Aaron

[yhafting]

Once you drop below 20 percent it will put you into I guess you could call it 'Rain Mode'.  It's very conservative on what it will allow you to do, your acceleration is limited but from what I have seen on my Ribelle, you can still get up to 80 MPH or more, just takes a bit to get up there, like maybe 15 seconds instead of maybe 3 or 4.

That is not true. There is slightly lower performance due to battery voltage dropping throughout the range, however if you experience any sudden drops in performance, it is usually due to cell imbalance, as is clearly the case for the OP. Ive had my share of poor performance due to cell imbalance, and i got a new battery on warranty- which does work well, even below 20%. A poorly balanced bike will at some point limit power output at nearly any SOC, but it can vary throughout the ride (ie if one cell is thoroughly depleted at 50% SOC, you will get limp mode at 50%, but stopping for 2 minutes may be all that it takes to clear it). 

A bike that is sold after running ~500 miles is probably not a good thing, because it likely has been sitting without being balanced for a long time. The bike does not balance well unless charged fully; although possible- it does not seem to be implemented that way (It may report some balancing attempt when DC charging at a rate that is near causing trouble with poorly balanced cells). 

When experiencing any sort of issue with balancing, make sure the bike does its balancing every day, rather than working it at 20-80%. If you are not able to bring the cells back into balance you will get all sorts of issues, and in the end you can have the bike limping above 50%. Balancing issues trumps any sort of longevity issues- there is no point in saving the top 20% if you have balancing issues which will cause issues with both regeneration at high charge status and limp mode at increasingly high SOCs.

The recommendation should always be prioritizing balance over longevity (replug when it has stopped charging to 100%). Make sure you replug when full at least once a week, and let the bike finish balancing. If balancing takes more than 10-15 minutes then do it again, if not before the next ride, then after. If the bike is not reporting 100% charge when starting a ride after charging to full, replug and let it balance.   

[vasculopath]

Thanks, taking it all in.  Can you explain "Replug"?

[DonTom]

Thanks, taking it all in.  Can you explain "Replug"?

I think he means . . . .


Disconnect when bike is done charging. Wait a few minutes and plug back in to charge.  It could start the charge again for a minute or so and balance the cells better.


-Don-  Reno, NV

[Specter]

Everyone has opinions, rarely is one person 100 percent correct or incorrect, because they / we / me can't see YOUR bike and YOUR specific situation, so keep that in mind also.

if your bike is having balancing issues THAT bad, there is a bigger problem going on.  Cells being connected will tend to self balance a little bit between each other just as a general rule on how that works.  If one cell is dropping THAT bad and taking out an entire arm / bank, then there is something else majorly wrong.  ideally the thing was fully charged AND balanced properly when they sold it to you.  Normal day to day running should NOT unbalance them that badly, since they all are hooked in ONE circuit and should, ideally charge / discharge at the same rate!  Again if something is unbalancing THAT BAD, that's looking more like a warranty issue for a bad cell in the entire battery pack. 

Lets say you have a string of 12 batteries in series and one in the middle is super low.  Yes THAT WILL take out that entire arm, especially at the point where that one low battery bottoms out and the voltage crashes.  BUT the problem is, when you go to 'balance' the battery, to charge that ONE battery back up, the other 11 in the arm MUST take the charging current as well, since they are all in series!  Unless you can get in there to that ONE battery and charge it up, it's going to take a long long time if EVER for it to finally balance out with the rest in it's string, IF it ever truly does, and will do so at the expense of the others in it's string.

Also keep in mind, Lithium cells, Unlike lead Acid cells, do NOT like to be continuously topped off, kept at top charge, so pushing them to their upper limits volt wise to micro balance them, is NOT good overall for the longevity of the cell.  Most if not all LiIon packs and most the Li chemistries will tell you, do NOT trickle charge.  if it's sitting for a month or so because it's winter / you are on vay cay etc, that's one thing, but sitting a few days or a week, NO it should NOT be draining that bad or need constant rebalance.

If you charge the battery pack, and it say's  'charged' and you wait 5 minutes and un / re plug in and it goes immediately back into a balancing mode and DOES balance for a significant period of time, there is a problem that needs a dealer's attention.  It should have balanced in the first, second AT a very worse case shot.

Use your best judgement, but be mindful you do not OVER charge the batteries, trying to balance them to much.

Most of the wear / damage to Li batteries comes from the top / bottom 5 percent of their charge range, and of course exceeding those ranges.  going low, they typically crash very quickly and should take the circuit out on it's BMS safety, going high now, just cooks things, and could possibly end up in thermal runaway.  There is physical damage as well as dendrites form in the battery which threaten to short out the plates when you continuously take it to it's outer limits.

Don't take my word for it though, please, look around.  Most manu's will advertise,  if you go basically 80 percent DOD, we'll give you, say 10k cycles,  (80 dod ideally means a 10-90 or 20-80 operating range, they want you to keep off 'the edges' of it's charge footprint) ask them for specifics.  but if you go full 100 percent Dod, they' only warranty it for say 3 to 5k cycles.  Yes, Topping Off or Bottoming out DOES take that much out of it's life span.

Aaron

[vasculopath]

Ha, did I stumble into the Electric equivalent of the "oil thread".