testing capacity of Shimano battery?

[TwisterGripper]

Hi all, I'm wondering if anyone knows if it is safe to test capacity of shimano BT-e8020 battery using basic watt meter tool and a resistor for load (Grin 6.8ohm 400w resistor)? not sure if I can treat this battery the same as most ebikes and just connect + and - to the main batt terminals...or will i mess something up with the proprietary BMS shimano uses? just a bit nervous to try it as I dont know if the BMS will cause issues.

Edit: using this method with a 0-100a watt meter and a 400w resistor: https://www.youtube.com/watch?v=Jc-6crET3Wo "just ride the bike" responses....well i'm looking to get a somewhat accurate measure of the remaining capacity here.

 

[LewTwo]

That is a good reason to avoid proprietary systems like Shimano and Bosch.
They want you to take it to the dealer and pay them to answer your question.

 

[E-HP]

Hi all, I'm wondering if anyone has been able to test capacity of shimano BT-e8020 battery using watt meter tool and a load? not sure if I can treat this battery the same as most ebikes and just connect + and - to the main batt terminals...or will i mess something up with the proprietary BMS shimano uses? just a bit nervous to try it as I dont want to risk damaging a $1000 battery.

Luckily the pack is only worth a third of that, so don't have to be as nervous. Why do you need to test the capacity?

 

[TwisterGripper]

Don't understand your question. Is the battery mounted on an ebike?
Have you ridden said ebike? How far will the bike travel on a full charge with moderate pedal assist?
If you know the spec's of the battery which I am sure you can look up, you can determine how many volts it is, put it on the charger, charge it to maximum and then measure the voltage with a multimeter to see how high it charged to.
The rest is just riding the ebike and determining if the amp-hrs of the battery spec comport with how far you went at say 250 ave. watt usage. The bike is the load and you are the watt meter.

Battery is removable. it is mine. i actually have 2 of them. one seems to have less capacity than the other.
unknown mileage and usage on both (bought used). I want a more accurate test to get the watt-hours remaining and compare to spec to get an idea how much capacity has been lost vs new. This is a mountain bike used pretty much only on singletrack, so Just riding the bike will not give me an accurate number (or any number aside from mileage)

 

[TwisterGripper]

That is a good reason to avoid proprietary systems like Shimano and Bosch.
They want you to take it to the dealer and pay them to answer your question.

I don't entirely disagree with you, and I'm fully aware of the pros and cons of buying into such systems vs diy. but really i just wanted to hear from someone who may have tested one of these batteries to assure me it was ok to test using standard methods. I highly doubt the dealer would know how to test the battery, in fact I know they know less than me...

this is off topic, but I bought shimano because I love mountain biking and wanted the best experience, the bafang mid drives did not (maybe still dont or maybe they do I don't know) have the tuning and finesse and natural feel of the bosch or shimano systems. Review after review proves that yes some of the bafang mid drives have a lot more power, that power is harder to control, and does not have as good tuning and natural feel. That said i am considering a bafang custom for my next bike, but need to learn more about how tuneable it is.

 

[TwisterGripper]

That is a good reason to avoid proprietary systems like Shimano and Bosch.
They want you to take it to the dealer and pay them to answer your question.

What is really funny, coming to this forum, virtually everybody here 'get's it' and is in lockstep on this issue.
This position comes naturally to those with a technical background and completely over the head of
non-technical people. They don't understand the proprietary money grab and as a result, consumers spend 2x's the $$ for a 'weaker' product. I would 'never' buy an ebike with proprietary drive system. Most systems you mention, for even a further money grab and proprietary hedge, are CANBUS architecture to prevent substitute with 'better' replacement parts.
And of course, there has been no response from the OP when asking for context. In other words, poetic justice.
But we can discuss it.

Wow, what an Elitist, snobby, insulting and condescending comment. You've made a bunch of incorrect assumptions about me. butt out if you don't have anything constructive to say. Also whining about no response with less than 24 hours since orig post? People have lives.

I chose this bike (Devinci AC) because its a kick ass Enduro EMTB and i ride rooty, rocky, downhill, rough terrain, stuff a bolt on bafang would get destroyed on.

Buying new, these brands have crazy pricing I agree, but I paid $4500 CAD for a good, used, hard core enduro EMTB, made in Canada by a reputable manufacturer, with a proven reliable shimano e8000 system. I knew exactly what i was getting. If something goes wrong with the motor yep, send it to shimano is the only real option normally. fully aware. I "get it". I "understand". There are advantages to these bikes, not just disadvantages. Maybe you don't "get it" or "understand"...see how insulting that comes across?

 

[TwisterGripper]

.... test capacity of shimano BT-e8020 battery using watt meter tool and a load? ....just a bit nervous to try it as I dont want to risk damaging a $1000 battery.

Luckily the pack is only worth a third of that, so don't have to be as nervous. Why do you need to test the capacity?

If you can direct me to a seller selling the BT8020 battery for only around $300 i would love to see it. I could not find one used for less than $800. Also sorry wasnt clear - this is CAD...so maybe $600 usd. I suppose if one pack is too worn maybe I could find a reputable company to rebuild it...

I want to test it to see how much capacity has been lost vs new. I can still get a good ride in, but after only 20-25km of rough singletrack, battery is nearly depleted...pretty sure it should go longer. they are 4-5 years old now and may have seen a lot of use.

 

[E-HP]

.... test capacity of shimano BT-e8020 battery using watt meter tool and a load? ....just a bit nervous to try it as I dont want to risk damaging a $1000 battery.

Luckily the pack is only worth a third of that, so don't have to be as nervous. Why do you need to test the capacity?

If you can direct me to a seller selling the BT8020 battery for only around $300 i would love to see it. I could not find one used for less than $800. Also sorry wasnt clear - this is CAD...so maybe $600 usd. I suppose if one pack is too worn maybe I could find a reputable company to rebuild it...

I want to test it to see how much capacity has been lost vs new. I can still get a good ride in, but after only 20-25km of rough singletrack, battery is nearly depleted...pretty sure it should go longer. they are 4-5 years old now and may have seen a lot of use.

I didn't say anything about cost, I said worth. You can pay whatever you want, but it doesn't make the pack worth that much. It's likely a 10S4P pack (36V 504Wh), so 40 cells.

Let's assume they are quality cells, since the lawyers wouldn't sign off on using cheap cells, then that's 40 cells, at maybe $6 each, or $240 of cells. So, you pay $760 for the case and BMS, cost-wise. I'm saying the worth is much less. But it's up to you what you want to pay for it, but doesn't make much sense to pay the cost of a proprietary battery, if you are using as a general ebike battery.

 

[TwisterGripper]

...

...

...

Elistist perhaps in the sense, I have forgotten more about EV tech than you ever considered, so yes, guilty I suppose.
You wasted your money. You will figure this out when your bike breaks and it will because all EV's do eventually.
Your battery is getting weak so get ready to get out your wallet and overpay for another crappy Shimano proprietary battery with poor amp-hr capacity with unknown cell type.
I will butt out as requested to preserve forum decorum but with a parting comment.
Your question was hollow and why it hasn't garnered a substantive reply, nor will it.
Have a good day and on your left..lol.

Again you assume to know everything about me and what I know. More condescending BS. I have enjoyed amazing epic rides on this bike for 3 years so far so its hardly a waste. "All machines break eventually", wow what an insight! Known good quality cell brand and type...more bs from you.

 

[TwisterGripper]

I have forgotten more about EV tech than you ever considered....
I am a scientist.
If you knew anything....
this is funny to many here...
If you want me to hold your hand or feel sorry for you...
you aren't smarter, it won't happen....

I'm not embarrased, but you should be with your above comments. checking the remaining capacity of a battery is not a dumb question, quite reasonable. "watt meter and a load" wording was for brevity not detail. recommended tools from GRIN...far from farcical.
The only thing unreasonable here is your nasty attitude and continued assertion about how smart you are....if you have to say it, you're probably full of it.
This is a forum for constructive discussion. You have added nothing to this conversation, so again please just quit your bs and bugger off.

 

[TwisterGripper]

.... [/b][/i].

I didn't say anything about cost, I said worth. You can pay whatever you want, but it doesn't make the pack worth that much. It's likely a 10S4P pack (36V 504Wh), so 40 cells.

Let's assume they are quality cells, since the lawyers wouldn't sign off on using cheap cells, then that's 40 cells, at maybe $6 each, or $240 of cells. So, you pay $760 for the case and BMS, cost-wise. I'm saying the worth is much less. But it's up to you what you want to pay for it, but doesn't make much sense to pay the cost of a proprietary battery, if you are using as a general ebike battery.

I see, yes i assumed you meant market value. This is being used with the shimano e8000 system so i don't really have a choice as far as batteries go. I'm considering selling and trying a build with bafang M620 and a Dengfu carbon frame (like the Luna X2)... I just would like to be able to honestly tell any potential buyer some approximation of life left on the 2 batteries.

 

[LewTwo]

I see, yes i assumed you meant market value.

My late father told me to never assume.
E-HP used the plain English word "worth" and it was clear to everyone else what his meaning was.

This is being used with the shimano e8000 system so i don't really have a choice as far as batteries go. ... ...
I just would like to be able to honestly tell any potential buyer some approximation of life left on the 2 batteries.

You bought into the Shimano system which means that you bought into their marketing strategy as well (with your eyes and wallet wide open). You need to take your bike and batteries to one of their authorized dealers and have them determine the remaining capacity of the packs.

 

[TwisterGripper]

I see, yes i assumed you meant market value.

My late father told me to never assume.
E-HP used the plain English word "worth" and it was clear to everyone else what his meaning was.

This is being used with the shimano e8000 system so i don't really have a choice as far as batteries go. ... ...
I just would like to be able to honestly tell any potential buyer some approximation of life left on the 2 batteries.

You bought into the Shimano system which means that you bought into their marketing strategy as well (with your eyes and wallet wide open). You need to take your bike and batteries to one of their authorized dealers and have them determine the remaining capacity of the packs.

Yes that was a simple mistaken assumption, but the word "worth" can certainly be taken to mean "market value". As in "this bike is worth $3000 on the used market."

It seems you have assumed I bought this bike new...I did not - i paid roughly half of retail used (what it's "worth" lol)...which is pretty comparable to the cost of building a M620 based bike with Dengfu frame. Ongoing serviceability yes would cost more in the long run, but I never planned to keep it long term. 3 years zero breakdowns so far. I appreciate your concern for my wallet but no I didnt over pay. I would never buy one of these bikes new, unless $$$ was no concern.

I can just pull the pack apart and test bypassing the bms of course, but was just hoping maybe someone else knew any tricks/had an easier way.

 

[LewTwo]

It seems you have assumed I bought this bike new...

For the record, no I did not.
My father was in many ways a wise man.
I have found his advice in this regard to be very reliable.

FYI:
I made a similar mistake with a Vespa scooter.
Difficult to get parts for and impossible to find a dealer within 500 miles.
(The local Lamborghini dealer used to service them).

 

[E-HP]

Yes that was a simple mistaken assumption, but the word "worth" can certainly be taken to mean "market value". As in "this bike is worth $3000 on the used market."

It seems you have assumed I bought this bike new...I did not - i paid roughly half of retail used (what it's "worth" lol)...which is pretty comparable to the cost of building a M620 based bike with Dengfu frame. Ongoing serviceability yes would cost more in the long run, but I never planned to keep it long term. 3 years zero breakdowns so far. I appreciate your concern for my wallet but no I didnt over pay. I would never buy one of these bikes new, unless $$$ was no concern.

I can just pull the pack apart and test bypassing the bms of course, but was just hoping maybe someone else knew any tricks/had an easier way.

I've noticed during the last year, the landscape is really shifting with the factory bikes and there are actually a few bikes that are almost a bargain. Enough that if I wanted an ebike for my wife, I would consider buying a factory bike. Cost, worth, value all seem to be lining up in some instances.

BTW I commend you for wanting to make sure the buyer knows what they are buying. I hear the opposite story a lot while reading this posts on the forum. The general advice seems to be, if you buy a bike with a used battery, place a low value on the battery when determining your offer.

 

[nicobie]

This thread is getting a bit too contensious so I'll be shutting it down for a while in order to calm things down.

Remember... insults ARE NOT ALLOWED.

Thanks

 

[nicobie]

OK, thread is unlocked, so play nice...