Erolling Bikes - the new kid on the block.

[Nick H]

After months of research and test rides I have taken the plunge and purchased a Step Through from Erolling Bikes; in fact I bought two at 449 GBP each. Of course the price was a major consideration but I cant see that these bikes differ from those that cost two or three the price; time will tell. I saw them on Ebay, went to their showroom, liked what I tested and settled for rear 36v hub, 10ah battery. I considered the Hub gears but elected for what I know. We purchased an extra 10ah battery for each bike for a total of 1200 pounds. I can report that the first hundred miles have been a great pleasure and we have achieved over 40 miles per Charge. I will keep you posted.........

Regards
Nick

 

[Mike63]

Nice one Nick...can't find 'em on ebay...you have a link ?
....Mike

 

[flecc]

Nice one Nick...can't find 'em on ebay...you have a link ?
....Mike

Here's the supplier link Mike:

Erolling bikes

 

[Mike63]

cheers Flecc...wonder if they're as good as they look.
....I wonder also how much this kind of stuff contributes to keeping the price down on some other bikes.

 

[flecc]

They look to me as just generic Chinese e-bikes bought in from various suppliers Mike, I recognise some of them as appearing under other names at different times. The usual question mark will be the lithium batteries, usually those on these bikes tend to fail by about 18 months depending on usage. They are usually old tech li-ion manganese which we've known plenty about from 2007 onwards.

They do bring some pressure on prices at the lower end, but don't dent the high end at all.

 

[HD462]

The black mountain bike style one looks very similar to the one I tried by Poweredbicycles.co.uk at a show. If it is it was a nice ride, and I would have bought one if I could have got it on our Cycle to Work scheme. Lower spec gears than the Peak I eventually got, but that probably allowed them to fit the disc brakes.

 

[Nick H]

Maybe, but at 450pounds and 150 for a spare battery 18 months would suffice. However, I suspect you will be proved wrong in that I think these are reasonable quality LiPo. You are correct that these are generic Chinese ebikes; so is almost everything else that retails under 1500 pounds. I also think these bikes are a game changer and will bring a significant number of people to the joy of ebikes and shake the complacent closed shop up a bit.

 

[flecc]

Time will tell on the battery life, butiagree 18 months is enough. However, there's no chance this ersatz range will shake up the market.

How do I know? Because we've seem it all before, a mixed bag of low price buy-ins imported by someone for a short period of time before they withdraw from the market. So many names I've long since stopped trying to remember them all.

 

[eddieo]

Jaded looking collection of bog basic Chinese ....Now how can I say this politely.....I cant

 

[alfazzr]

Nick, do you know if you got a special price on the battery - they quted me £190 for battery and charger as a spare (without the bike) ?

How are you going to store your spare batteries? Important I understand. the Electric Tranpost on their website recomends:

"If the battery will not be used for more than 4 weeks it should be stored at a storage voltage of approximately 40% of it's operational voltage, e.g. a 36V battery should be stored at roughly 39V."

.....but I guess there is a typo in that statement as I do not understand it !

Good luck with the bikes.

Alfazzr

 

[flecc]

"If the battery will not be used for more than 4 weeks it should be stored at a storage voltage of approximately 40% of it's operational voltage, e.g. a 36V battery should be stored at roughly 39V."

.....but I guess there is a typo in that statement as I do not understand it !

Good luck with the bikes.

Alfazzr

It's correct Alfazzr. That's because the fully charged voltage of a lithium-ion nominally 36/37 volt battery is actually 41.5 volts. As the charge content falls, the quiescent voltage drops slightly, and with a new and healthy battery, 39 volts quiescent represents approximately 40% of charge.

 

[alfazzr]

Yes but it says's 40% of its operational voltage and 40% of 41.5 volts is 16.6 volts.

 

[flecc]

That part of the statement is incorrect, it should read 40% of charge, not voltage, which is the correct level of charge for storage and obviously what they mean.

Well before getting as low as 40% of voltage, a lithium cell will be destroyed, never to work again.

 

[alfazzr]

Thanks for clarifying that Flecc. I wasn't sure what they meant.

 

[Tinker]

Sorry to butt in but I've got confused.
Please could you confirm what is the correct storage voltage for a 36v batt?
I'm having a thick day and whilst I understand 40% of the charge can be 39v, is 39v the correct storage for 4 weeks(ish) & whats the charge voltage.

 

[flecc]

Really these figures for long term storage mean longer than four weeks and nothing will be gained by juggling voltages for such short periods. Additionally, genuinely long term storage only saves battery life if done at near to zero degrees C as you'll see from this Battery University chart:

At 25 degrees there can be a saving of 16% capacity after one year, so for four weeks the saving will be at most just over 1%, hardly worth all the bother of trying to adjust the charge levels, especially since this is theoretical and isn't guaranteed in practice.

However, to answer your questions, the charge voltage is 42 volts and storage voltage 39 volts for roughly 40% of charge left.
.

 

[alfazzr]

That's really interesting - as most people do not have room in the fridge for a spare battery, I wonder if sticking it in the chest freezer is an option. (Have to ditch a few fish fingers first though !)

 

[flecc]

No, definitely not. Below freezing at freezer temperatures will ruin the cells. Fridge temperatures are ok, but as you imply, not really practical and also not constant temperature in domestic use.

For most people in most circumstances, these special storage techniques are not worthwhile.

 

[Tinker]

Thanks flecc

 

[Nick H]

I am not aware that I was given a special price for the additional batteries; it is what they quoted as part of a two bike package.