Battery advice

[Godzy89]

Hi everyone
Just got my first ebike and am looking for a bit of general advice about charging the battery
Am i better to let the battery run out of charge or can i recharge it to full even if its only partially empty
Sorry if its a dumb question lol

Thanks for any replies

John

 

[lightning]

What kind of battery is it? lf it's a lithium one it doesn't matter about fully discharging it before you recharge.

They do say to fully charge it before the first use though.

 

[Godzy89]

Thanks for the reply
Pretty sure its lithium
The bike is an Orbea Vibe H30

John

 

[matthewslack]

Running it fully flat will shorten its life. Avoid doing this as much as you can, and try to keep 20% 'reserve' that you only use if really pushed for range. But use it if you need to, the bike is a tool after all.

Don't leave it sitting for days at low charge or full charge. Ideally store at half or a bit over, charge to nearly full or really full before riding, depending on how far you are going.

 

[Andy-Mat]

Hi everyone
Just got my first ebike and am looking for a bit of general advice about charging the battery
Am i better to let the battery run out of charge or can i recharge it to full even if its only partially empty
Sorry if its a dumb question lol

Thanks for any replies

John

There are so many opinions on Li-ion batteries, that hardly two Pedelecers can agree on anything.
I have had good results (never lost a battery in 12 years of e-biking) with the following:-
1) assuming a normal charger, I add a cheap 24 hour timer, to shut the power off to the charger, when I believe that the charge will be finished, I also rewire the timer, so at the same time all power is removed from the tiny motor in the timer as well! Its usually just moving a single wire to a different position!
There are some expensive chargers that remove all power, once the battery is full, but the only one I have ever seen, stll switched power back on if the charge dropped - not good IMHO in the longterm!
I prefer chargers with tiny fans inside to make sure the electronics are kept cool. Not all chargers have this feature.
2) Riding an e-bike till the BMS stops supplying power should do no harm to the battery, assuming that the BMS has been set correctly of course. On a 36v Nominal battery, that should be just over 30 volts if my memory serves me correctly. Buy a reasonable Multi Meter so that you can check such things out. Check also that the battery is at or close to 42 volts when charged (assuming a 36 volt battery of course!). Not over 42 volts (again assuming 36 volt battery).
If you don't like peddling home, then buy a second battery and take it with you for long distances.
3) I only charge my batteries when the BMS cuts power, as the bike is a daily user, unless its icy or snow, this is not a problem.
4) When its freezing, take the battery into the house, but only charge it, on a surface that will not burn etc., when you are home. Have a smoke detector near to the battery. I myself have never had one catch fire, but others have.
5) If you are not a fully qualified electrician, never play about with batteries, keep everything the way it was delivered. Tying to run two batteries together can cause some nasty fires for the uninitiated!
This bike on YouTube has two batteries, one on the downtube, one on the carrier, look what happened:-

6) Always treat batteries as if they are sticks of dynamite......
best wishes
Andy
PS. A full discharge should be automatically prevented by the Battery BMS, and it should cut power to the motor at a safe voltage level. A true full discharge would damage the battery, even if brand new.

 

[Russ34]

This is the information from the company I bought my battery from if that helps at all !

 

[Godzy89]

Thank you all
Will definately take everything into consideration and especially after watching that video
As i originally stated this is my 1st ebike and i certainly dont want to burn the house down with it - the mrs wouldnt be too happy lol

 

[lightning]

You shouldn't be able to run the battery completely flat as the BMS will shut down the bike before this happens.

lf you do get back from a ride with the battery down to under 10% it's important that you don't leave it in a discharged state, as that can damage it.

Charge it ASAP.

 

[Nealh]

Deep discharge is down to 3v - 2.5v per cell group, though depending on the cell it may start a bit higher. Do the homework on the cell used in your battery and then look at the graphs to see where the linear fall declines and the dive off the cliff starts.
All of my BMS stop discharge at approx.3.2v per cell group so 22v for 24v battery, 32v for a 36v battery & 38v for my 44v battery.

One can see the deep discharge by looking at discharge graphs and the point at which the voltage dives off the cliff.

Two examples of cells commonly used in generic batteries.

 

[Nealh]

This one is of the LG hg2 I use in my drinks bottle battery.

The curve is very linear in decline but at approx. 3.2v it like most starts to decline more.
If I have a spare battery on a run I will often stop discharge at about 3.5v and change battery but I know I have some reserve to use if needed or on a longer run so will on a flatter less demanding part of the return use any battery to it's cut off or just above.

Having a watt hour or a voltage reading is indispensable, I would never rely on led lights as they simply are no way accurate enough.

 

[Godzy89]

Battery is now fully charged and i have linked it to the Mahle app which states a 25 mile range?
The bike is supposed to do 62 mile on a full charge
Have i done something wrong?

 

[sjpt]

62 miles is 'maximum' range (often called 'up to' range). This assume ideal conditions, good flat road, light rider, no wind, minimal assist level, summer, etc. Typical real world figures with a middling level of assist are usually around 1/3 'up to' figures. It's more likely 25 miles is a realistic value than that you've done something wrong (other than believed the advert).

Try https://www.bosch-ebike.com/en/service/range-assistant/
This is for Bosch bikes, but gives a pretty good idea for most ebikes as long as you allow for battery capacity and motor type. Even though you may not get a good absolute range value for other ebikes it still gives a very good idea of the range difference with different riding conditions.

I don't know how the app interprets likely range, but you'll probably find that after a few minutes riding it changes maybe up or maybe down as it learns your riding style and conditions. Estimated range will almost certainly respond instantly to change in assistance setting.

The estimated range on the Bosch Intuvia (that is the range from the bike hardware, not from the range assistant mentioned above) adapts absurdly fast to changes in conditions, just seeming to take account of the last few of miles. It may well say a bit over 35 miles on a charged battery, then be down to not much over 20 miles after two miles up not that steep hills. It'll creep up again on the flat, after 10 flat miles it might say 20 or 25, but by the time I'm home it'll look at the last to miles downhill and be back at nearly 30. I suspect that the Mahle app will behave slightly more sensibly.

 

[Nealh]

62 miles from 248wh one would have to be consuming 4 wh/m to achieve that and certainly above the cut off limit nearly all the time.
The app is assuming a modest 10wh/m which is about average usage for a regular rider, an everyday rider or above average rider who is ride fit should manage low 6 or 7 wh/m but it does depend how the motor rides with human input above the cut off speed.

 

[soundwave]

on my bike with that display the range calculator is useless with a dongle lol

 

[sjpt]

on my bike with that display the range calculator is useless with a dongle lol

but only marginally less useful than it would be without the dongle.

 

[Godzy89]

Might be a daft question but thats only when assistance is on yes?
More than happy to pedal and just turn the motor in when needed

 

[lightning]

lf you only turn the motor on when needed, such as on hills, and then use as little assistance as you can get away with, then you will approach the claimed maximum range of the bike.

My Ebike claims 50 mile range but keeping the assist on "medium" 90% of the time and riding in hilly terrain means l just about manage 30 miles.

 

[Nealh]

Range has to be put in to context, the published figures will be done using a super fit rider on a flat course with no wind or rain. They will of course be riding above the 25km/h speed limit so actual assisted constant figure won't be a real world 62 miles.

 

[lightning]

Absolutely.

l managed 57 miles on my Kona when on holiday in Norfolk where it's flat as a pancake, and the battery still had one bar showing.

For instance on a 25 mile ride l only climbed 100ft.

Round here my shortest 7 mile loop has 1,000 feet of climbing.

 

[Godzy89]

Ah ok
Makes a lot of sense
Thank you again to everyone for the answers
Im getting out on a decent (for me anyway) ride at the weekend and will try it out and see what the app says at the end
Ride is a mixture of flats and hills

Just done a short 8 mile test ride and the battery is at 86% but the range has gone up to 37 miles