Free public battery charging scheme

[Nealh]

EAPC sales will never be a transport mode for the greater public as many will be fair weather users , 99.9% are glued to their cars.
A buy may start as a fad then they get left in the shed /garage and then battery care another alien subject will be an issue.
Even walking local short errands is alien to much of the greater public.

 

[daniel84uk]

I charge using electric car type 2 chargers with an adaptor. I am surprised ive never seen anyone else doing this on my travels. I guess people prefer shorter rides, whereas i like a day out. A charger is much cheaper and is much lighter than lugging multiple batteries around. One caveat is that you need a battery with good cells to be able to charge quickly. I charge at 58.8v @ 20amps or so, the power supplies to this can be had cheaply on ebay, only minoe tinkering is needed.

 

[AntonyC]

I know of two others doing exactly this. How has EV charging matured, is it a hassle needing multiple accounts and annual subs? Do supermarket filling stations generally have 3 pin outlets too?

 

[saneagle]

I charge using electric car type 2 chargers with an adaptor. I am surprised ive never seen anyone else doing this on my travels. I guess people prefer shorter rides, whereas i like a day out. A charger is much cheaper and is much lighter than lugging multiple batteries around. One caveat is that you need a battery with good cells to be able to charge quickly. I charge at 58.8v @ 20amps or so, the power supplies to this can be had cheaply on ebay, only minoe tinkering is needed.

20a 58v charger is a bit of a beast. How much does it weigh along with its leads, plugs and adaptors?

 

[daniel84uk]

20a 58v charger is a bit of a beast. How much does it weigh along with its leads, plugs and adaptors?

I use a power supply from a cellular base station as they are a close match to the voltage i need and widely available on ebay. Mines model Eaton APR48-3G It can go to 1800w or 30a or so for my battery. There are plenty of other brands and models. Its 1.7kg. I put a xt90 on and its a regular 3pin plug and a £8 type 2 adaptor.

 

[daniel84uk]

I know of two others doing exactly this. How has EV charging matured, is it a hassle needing multiple accounts and annual subs? Do supermarket filling stations generally have 3 pin outlets too?

Pay as you go. You just top up a minimum of £5. I near exclusively use podpoint as they are at every large tesco store and parking places. Ive used BP a few times and connectedkerb. The AC EV points are perfect for small vehicles like a bike, terribly slow and expensive for cars, not sure why people bother. They all use type 2 interface, i use an type 2 to 3 pin adaptor, they are £10 or so. Just works like plugging plug in at home. Podpoint even starts charging without for free for 10 mins or so.

 

[Nealh]

For the sake of an extra 1kg or 1.5kg for battery weight I don't see the faff for the charger routine on a ride. I take enough wh to manage a 160km ride and the bike takes the weight and isn't that noticeable unless one has to pick it up to carry.

 

[saneagle]

I use a power supply from a cellular base station as they are a close match to the voltage i need and widely available on ebay. Mines model Eaton APR48-3G It can go to 1800w or 30a or so for my battery. There are plenty of other brands and models. Its 1.7kg. I put a xt90 on and its a regular 3pin plug and a £8 type 2 adaptor.

So that thing is approximately the size of a Hailong battery without its leads and adapter, and it weighs about 2.5kg with cables and adapter, compared with about 3.5kg for a 56 cell 52v 13Ah battery that you can swap in about 10 seconds. I can't see what the advantage of your idea is.

 

[Fatgadget]

An aspect worth bearing in mind these days many landlords reticent ebikes stored on their premises let alone charged there due to the explosion of lithium battery fires!. So the scenario might well change.
Also bike charging facilities in tandem with roadside EV chargers currently being rolled out?

 

[AntonyC]

So that thing is approximately the size of a Hailong battery [...] I can't see what the advantage of your idea is.

£50 delivered is one advantage, you don't want a battery to cost that. My own charger weighs 1kg with the leads and is the size of an A5 book, it takes 20 minutes to add 15 miles but that's not a lot to carry.

It's not for everyone, you need the right battery and have to make sure charging tapers off well before it nears full, especially with fast rates. But only charging if need be can mean starting from 20% or so.

 

[saneagle]

£50 delivered is one advantage, you don't want a battery to cost that. My own charger weighs 1kg with the leads and is the size of an A5 book, it takes 20 minutes to add 15 miles but that's not a lot to carry.

It's not for everyone, you need the right battery and have to make sure charging tapers off well before it nears full, especially with fast rates. But only charging if need be can mean starting from 20% or so.

Chargers don't add miles, instead they add watt-hours. In that context, can you explain again which charger you have and what it does? Also, where do you find a place to plug in your charger? In 15 years of ebiking, I've never passed anything like that. Surely, you'd have to divert into town, which is going to add extra miles to your journey and eat up a fair chunk of your 15 miles.

If you use that EATON APR48-3G charger at 20A for a typical ebike battery, the battery will have a very short life, so that £50 will become £400 for a new battery and the charger. I think the idea of doing that is completely flawed for an ebike. I can understand doing it on a small electric vehicle that has a sizeable LiFePO4 battery, but not an ebike.

 

[Tony1951]

If you use that EATON APR48-3G charger at 20A for a typical ebike battery, the battery will have a very short life, so that £50 will become £400 for a new battery and the charger. I think the idea of doing that is completely flawed for an ebike. I can understand doing it on a small electric vehicle that has a sizeable LiFePO4 battery, but not an ebike.

I was thinking that the other day when I read the post. 58.8v @20 amps is nearly 1200 watt charge rate. It is getting towards the power used in a cheap electric kettle. A significant amount of battery heating must be created in charging like that, not to mention an increased risk of a battery fire. You don't need to take the cells much past 60c for the risk of thermal runaway to get going.

Obviously the more cells you have in parallel in the battery the less risky it is. My 10s 6p battery is charged at 3 amps and the 10s 3p one is charged at 2 amps.

 

[matthewslack]

Depends on the battery Ah capacity too. 20A into 20Ah is only 1C. Car fast chargers are much higher than that, although the battery packs are rather more sophisticated from a heating/cooling point of view.

Obviously lower is gentler, but is there a 'generally recognised' maximum desirable C rate for ebike battery charging?

 

[Tony1951]

An aspect worth bearing in mind these days many landlords reticent ebikes stored on their premises let alone charged there due to the explosion of lithium battery fires!. So the scenario might well change.
Also bike charging facilities in tandem with roadside EV chargers currently being rolled out?

You are joining the battery fire hype I'm afraid, and fanning the flames.

The actual recorded number of bike/scooter battery fires in the UK last year was 211

Source: https://www.gov.uk/government/publications/fires-in-e-bikes-and-e-scooters/fires-in-e-bikes-and-e-scooters-2024

The number of fires in general in the UK in 2024 was 133,072.

One fire in every 630 in the UK last year was caused by an e-bike or e-scooter.

The Bike Association claims that there are 550,000 e-bikes in use in the UK, so one bike in every 2606 caught fire, and you can bet that fast charging or fast discharging was a major contributor to those fires.

By comparison, with 41.2 million road vehicles and 100,000 vehicle fires per year, the ratio for road vehicles generally is one fire in 412.

What explosion of lithium battery fires?

This whole mythology about lethal ebikes is a got up exaggeration put about by the trash media and people blabbing on the Internet.

If you ill-treat a lithium battery it might catch fire and burn your house down. Every home is filled with other stuff that will do the same if treated badly. nevertheless, we are left with the fact that only one fire in 630 was caused by an e-bike or scooter in 2024.

The fact that ebike fires are increasing in percentage terms is a feature of much greater numbers of them being in circulation. In absolute terms the numbers of new fires is small. A percentage rise of a small number is still a small number. Too many people writing for the media have no grasp of basic statistical concepts.


This is quite an interesting page:

https://www.honestjohn.co.uk/the-latest-car-fire-statistics/

 

[saneagle]

You are joining the battery fire hype I'm afraid, and fanning the flames.

The actual recorded number of bike/scooter battery fires in the UK last year was 211

Source: https://www.gov.uk/government/publications/fires-in-e-bikes-and-e-scooters/fires-in-e-bikes-and-e-scooters-2024

The number of fires in general in the UK in 2024 was 133,072.

One fire in every 630 in the UK last year was caused by an e-bike or e-scooter.

The Bike Association claims that there are 550,000 e-bikes in use in the UK, so one bike in every 2606 caught fire, and you can bet that fast charging or fast discharging was a major contributor to those fires.

By comparison, with 41.2 million road vehicles and 100,000 vehicle fires per year, the ratio for road vehicles generally is one fire in 412.

What explosion of lithium battery fires?

This whole mythology about lethal ebikes is a got up exaggeration put about by the trash media and people blabbing on the Internet.

If you ill-treat a lithium battery it might catch fire and burn your house down. Every home is filled with other stuff that will do the same if treated badly. nevertheless, we are left with the fact that only one fire in 630 was caused by an e-bike or scooter in 2024.

The fact that ebike fires are increasing in percentage terms is a feature of much greater numbers of them being in circulation. In absolute terms the numbers of new fires is small. A percentage rise of a small number is still a small number. Too many people writing for the media have no grasp of basic statistical concepts.


This is quite an interesting page:

https://www.honestjohn.co.uk/the-latest-car-fire-statistics/

I wouldn't disagree with any of that. Car batteries have sophisticated pre-conditioning and cooling systems to control temperature when fast charging and the charge rate is adjusted according to the state of charge. I don't think you can make any comparison with ebike batteries other than to figure out that if it's necessary for cars, it should be necessary for ebike batteries too if you charge at the same rate. Maybe that might have something to do with all those deliveroo bikes exploding in their owner's flats.

Obviously lower is gentler, but is there a 'generally recognised' maximum desirable C rate for ebike battery charging?

It's just a case of the slower the better, and the risk of damage or catastrophe goes up exponentially with the rate of charge, but there are other factors too that have to be considered. It's supp9sed to be bad for the cells if you start charging them at a high rate when they're at a low state of charge or not pre-warmed. Likewise, the charge rate has to be reduced when the cells start to get full because there is less room for the electrons to find their place, so charging at a fixed high rate should be safer in the range 20% to 80% than 0% to 100% , but it's not like 20% is OK and 19% will explode. It's a continuum. There is no border.

To answer your question, recommended charging rates have always been 0.2c, but like eating salt or sugar, there are recommended maximums, and some people go wildly over and never have any problems, while as others aren't so lucky, and when they have problems, you can't say definitely what was the cause.

 

[daniel84uk]

I was thinking that the other day when I read the post. 58.8v @20 amps is nearly 1200 watt charge rate. It is getting towards the power used in a cheap electric kettle. A significant amount of battery heating must be created in charging like that, not to mention an increased risk of a battery fire. You don't need to take the cells much past 60c for the risk of thermal runaway to get going.

Obviously the more cells you have in parallel in the battery the less risky it is. My 10s 6p battery is charged at 3 amps and the 10s 3p one is charged at 2 amps.

This is not a standard low-cost battery of inferior quality. It was assembled by me using high-quality very low resistance cells and thick copper interconnects. and is certainly not light in weight. At a 1C charge rate, the charge current is approximately 20A. The cells are rated a much higher charge rate with appropriate cooling. The pack includes three temperature sensors distributed throughout the pack, and the end of charge temperature never exceeds 35 °C, even when enclosed without active cooling. The battery charge is largely self-regulating; internal resistance increases as it nears full charge, thereby reducing current. I also configured the charge voltage to be lower than the pack voltage. My intention is to achieve rapid charging from 20% to 80%. I dont use the entirity of the pack because i want the pack to last a long time, and it has, its now six years old and going strong.

It is important to note that my bicycle is relatively inefficient. Due to arthritis, I rely on the motor more heavily than most riders. I have installed thick heavy motorcycle-type tyres to eliminate punctures and ride at low pressures because the bicycle lacks suspension. The bicycle itself is small, with wheel diameter comparable to a Brompton. Previously, I disliked the need to plan in advance before going. Now, I require only about 30 minutes of charging before departure. For additional safety, I developed a custom application to monitor the battery during charging. For example, it can automatically terminate charging if the temperature were to reach 40 °C.

With a charger my range is effectively unlimited, i dont need heavy bulky addictional batteries, and it charges so fast it isn't any hassle at all. I also take my bike with me when 'wild' car camping so make extensive use of EV charge points on those occasions.

 

[daniel84uk]

I wouldn't disagree with any of that. Car batteries have sophisticated pre-conditioning and cooling systems to control temperature when fast charging and the charge rate is adjusted according to the state of charge. I don't think you can make any comparison with ebike batteries other than to figure out that if it's necessary for cars, it should be necessary for ebike batteries too if you charge at the same rate. Maybe that might have something to do with all those deliveroo bikes exploding in their owner's flats.

It's just a case of the slower the better, and the risk of damage or catastrophe goes up exponentially with the rate of charge, but there are other factors too that have to be considered. It's supp9sed to be bad for the cells if you start charging them at a high rate when they're at a low state of charge or not pre-warmed. Likewise, the charge rate has to be reduced when the cells start to get full because there is less room for the electrons to find their place, so charging at a fixed high rate should be safer in the range 20% to 80% than 0% to 100% , but it's not like 20% is OK and 19% will explode. It's a continuum. There is no border.

To answer your question, recommended charging rates have always been 0.2c, but like eating salt or sugar, there are recommended maximums, and some people go wildly over and never have any problems, while as others aren't so lucky, and when they have problems, you can't say definitely what was the cause.

0.2c is incredibly low though. It because of the poor quality cells they use, it doesnt have to be that way. I mean we charge our lipo phones at over 1c every night, and they are lipo pouches and sit in your pocket!

One of the reasons there are so many ebike fires, is that the series groups often only rely on the heashrink for electrical insulation and are glued together with only hot glue! Its a crazy common practise and very dangerous, especially on a high vibration environment like a bicyle.

 

[saneagle]

0.2c is incredibly low though. It because of the poor quality cells they use, it doesnt have to be that way. I mean we charge our lipo phones at over 1c every night, and they are lipo pouches!

Who's we? My phone has a 4500mAh battery and I charge it at 500mA. It's been going for about 5 years so far and still seems to last as long as it did when new - about 3 days.

 

[AntonyC]

0.2c is incredibly low though. It because of the poor quality cells they use, it doesnt have to be that way.

Also most ebike batteries use P-groups meaning there's no real control over individual cell current - in some ways the cells appear to support one another and all's well until it isn't. Battery makers leave substantial headroom too for temperature effects, ageing and BMS shortcomings in protecting against 'use beyond spec' i.e. us users. What's clear is horses for courses:
- for some a two battery swap is pricey but it's simple, immediate and reliable
- others favour a short wait in return for low weight and PAYG for low upfront cost
- current ebike battery performance is a market choice not wholly a tech limitation
- it's nice to have options