Bosch battery testing

[RustyMTB]

Interested in anyone's experience. My 625 battery feels like it's degraded a little over time, it's pretty much cooked on 20-25 mile rides whereas a year ago, 30+ was easily in reach. So I'm weighing up replacing it but before that, I'm minded to have it tested.

To that end, I spoke to an LBS who have a Bosch tester & in the course of the conversation, they mentioned that the test cycle which involves fully discharging can kill a battery. I asked them to quantify that & they said 'very rarely' which isn't particularly enlightening, so should I?

 

[Bones]

When I took my bike in for checking the battery out and showing them a few pictures of my flat battery with only 20 odd miles on the clock.
It got a software update for the EMTB mode to EMTB+ which supposedly gives 20% more battery milage by limiting the variable boost mode.
I can now get 30 odd miles from a challenging hilly ride.
Early days at mo as the update was only about a month ago and I'm currently in the Algarve on a hire bike with a 750 battery that's giving 50 miles from a very hilly challenging ride.
So the bigger battery is far superior to the 625 one.

 

[Spiff]

If the battery can be killed in a test, it probably may also suffer a "natural death" during a long ride, normally at the most remote location of the track. So if the test kills the battery, it is uncovering a battery issue and saving you the hassle.

Well, that's my opinion and I may be wrong.

 

[RustyMTB]

Not as much hassle as shelling out £800 for a new one when the old one still works though eh.

 

[Bones]

Not as much hassle as shelling out £800 for a new one when the old one still works though eh.

Merlin had them for around £430 a month ago. No idea what the current price is though

 

[RustyMTB]

They jacked them back up to £700

 

[RustyMTB]

So it's been tested. Two years old, 3700 odd miles on the bike & at a guess, 250-300 charging cycles. Anyone fancy a punt at what percentage is left in it?

 

[Hattori-Hanzo]

I'll be optimistic and say 99%

Though I suspect it's probably around 60-70%

 

[RustyMTB]

94.5% Not bad at all, I honestly thought it would be around 70-75.

 

[Gareth]

That’s what I’d expect. Mine has done a similar mileage over 3 years and it feels much as it did when new in terms of range. I do notice it is less lively in winter compared to summer, but overall, over time can’t detect a drop in performance – umm so far.

 

[Peaky Rider]

So if you have lost the range you say and your battery is pretty much okay, either you are riding through a lot of thick mud, have not been riding much in this miserable winter and so have lost fitness, or you have just got fatter.
Or, like me, all three.

 

[Ark]

So if you have lost the range you say and your battery is pretty much okay, either you are riding through a lot of thick mud, have not been riding much in this miserable winter and so have lost fitness, or you have just got fatter.
Or, like me, all three.

his leg muscles atrophied from riding an EMTB

Don't skip leg day

 

[JP-NZ]

So it's been tested. Two years old, 3700 odd miles on the bike & at a guess, 250-300 charging cycles. Anyone fancy a punt at what percentage is left in it?

Can you not see charging cycles on the pre-smart bosch system? I know you can in the flow app on newer models

 

[RustyMTB]

No & nor can you see battery health. I had to make a round trip to a shop to use their battery tester & leave the battery with them overnight. And cough up dollar.

 

[Hattori-Hanzo]

I'm surprised it's so little considering the mileage drop you describe.
Maybe other factors involved, winter riding, fitness, temperature, how accurate is the test

 

[RustyMTB]

I've thought about that too. My perception is the battery comes in about 10 miles short of where it was a year ago. I ride all year round, so have to take cold days & sticky conditions into account but I also ride a mix of solo & group rides.

On the group rides, it's almost always wth a couple of guys on normies at low speed & that nearly always sees the battery sip electrickery. When solo, I'm bombing around at full gas & burning through it. So it's a combination of factors & as with all things batteries, the answer lies somewhere in the how long is a piece of string? end of things.

As for the test itself, I have to accept it since it's the only one available but assuming it's accurate, then it looks like it's not you, it's me.

 

[Tubby G]

I've thought about that too. My perception is the battery comes in about 10 miles short of where it was a year ago. I ride all year round, so have to take cold days & sticky conditions into account but I also ride a mix of solo & group rides.

On the group rides, it's almost always wth a couple of guys on normies at low speed & that nearly always sees the battery sip electrickery. When solo, I'm bombing around at full gas & burning through it. So it's a combination of factors & as with all things batteries, the answer lies somewhere in the how long is a piece of string? end of things.

As for the test itself, I have to accept it since it's the only one available but assuming it's accurate, then it looks like it's not you, it's me.

Have you put loads of weight on ?

 

[The Hodge]

I'm surprised it's so little considering the mileage drop you describe.
Maybe other factors involved, winter riding, fitness, temperature, how accurate is the test

100% this regarding winter / cold weather ..there is a definite drop in range over the winter season ..which improves again in summer ..

 

[Tubby G]

100% this regarding winter / cold weather ..there is a definite drop in range over the winter season ..which improves again in summer ..

Different subject - Hope today goes ok Hodge

 

[Lazy Clydesdale]

How much does your rider aerodynamics worsen in winter? Everything comes at a price..

 

[RustyMTB]

How much does your rider aerodynamics worsen in winter? Everything comes at a price..

U wot m8? Aerodynamics? This isn't GCN you know.

 

[Lazy Clydesdale]

I made my own bodywork to improve my aerodynamics at Daytona, so I am a bit more interested in this topic than most..

Everything about winter air and dressing for it, plus the higher average speeds of an emtb, is feeding into the penalty.

Aerodynamics & Rolling Resistance At Different Speeds - FLO Cycling

I was recently working on a problem to determine the number of watts required to overcome aerodynamic drag and rolling resistance at different rider speeds.

blog.flocycling.com

"Notice how rolling resistance starts higher, the two meet around 10mph, and then aerodynamic drag takes off quickly. This is because of the cubic factor of the velocity component of the aerodynamic drag."

 

[JP-NZ]

So it's been tested. Two years old, 3700 odd miles on the bike & at a guess, 250-300 charging cycles. Anyone fancy a punt at what percentage is left in it?

On my 750 powetube I’ve done 1680 miles and on the flow app the battery has done 33 charge cycles.

Even if yours is a 625wh I think your charge cycles maybe a bit high.

 

[RustyMTB]

I don't count them, it was just a guess. based on mileage & number of rides.

 

[JP-NZ]

Yea I understand. It’s probably closer to 90-100 charge cycles. Hence why the battery health is still so good.

It’s a testament to the quality of the power tube batteries and Bosch system overall.