what capacity cells would be in 36v 17ah battery

[footpump]

hello all last year bought 36v 10.4ah bottle battery yosepower brand gives about 30miles using with 250w tdz2 moter on Carrera subway one.

swopped battery for 13ah to give more range but in reality its no better than the 10.4 one for range.

so I have been pondering what to do, new battery from say eclipse 30q cells/re cell from insat/ or something else.

I have decided to opt for 36v 17ah yosepower battery (this is same ebay seller I bought the above bottle battery from)
I am hopping that at last I can do a fairly hilly 25 mile in total trip at full power if need be, without forever wondering if I am going to run out of battery .
this battery seems fairly light at 3.1 kg so am wondering what cell capacity might be to makehttps://www.ebay.co.uk/itm/36V17Ah-Electric-bicycle-Li-ion-Battery-with-Cellphone-charging-USB-3A-Charger/222314423780?epid=2065113669&hash=item33c2f8e5e4:g:FJAAAOSwfkdZkt3z

this should fit same battery base already on the subway, so I can have a spare battery if need be
battery is 629 watts

 

[anotherkiwi]

5P10S = 3400 mAh probably LG INR18650-MJ1 3500mAh - 10A in that case
6P10S = 2850 mAh maybe an HG2 thay would be consistent with weight.

 

[NJS]

hello all last year bought 36v 10.4ah bottle battery yosepower brand gives about 30miles using with 250w tdz2 moter on Carrera subway one.

swopped battery for 13ah to give more range but in reality its no better than the 10.4 one for range.

When you say "swapped", do you mean actually exchanged, or bought another and left the old one in the garage?

Because if the latter, and you paralleled both, you'd have 23.4Ah for no extra expense. Might need to get creative about fitting them both on the bike.

 

[Deleted member 4366]

The Dolphin case can take a maximum of 52 cells, so that 36v one is 50 cells. 17Ah divided by 5 makes 3400mAh, but there are no 3400mAh LG cells, so something is wrong with the listing.

 

[footpump]

thanks all the battery is listed as yosepower ebb 0361170-qt-b
also found same battery on amazon but at £280
looking on the yosepower website cannot find the exact model number the nearest thing is a 48v but comes in various configerations.
e mailed the ebay surplier and received message website not updated(not sure if that's referring to ebay or yosepower)

have asked ebay surplier whats the configuration of batteries and ah etc
not as yet received replyhttp://yosepower.com/product/p3/p5/2017-06-13/152.html.

the yosepower site shows Samsung cells some of 3.3ah capacity.
your thoughts please

 

[footpump]

sorry all link does not seem to work but its downtube battery on yosepower homepage under product

 

[anotherkiwi]

https://eu.nkon.nl/rechargeable/18650-size.html most popular batteries listed on this page.

Closest would be the Samsung 35E.

The other battery might be 17.5 Ah and they didn't find the .5 on the keyboard...

 

[Nealh]

I think the cells are LG 3350mah F1L's but for some reason they are rounded up to 3400mah, at £280 you ain't going to get MJ1's.
The F1L is not a great cell but just a so so mediocre 5a rated one for low power set ups, the battery should be listed as 16.75ah. As long as you don't use high amp draw it should be good for a 2,3 or 4 years, it's main advantage will be range.
Config will be 10S 5P.
All good celled batteries (10a + rated) are not cheap, most are over £300.
Cells generally under £300 are 4 - 7a rated like Samsung 22 or 26E, 26H, 32E & 33G. Also the F1L.

 

[anotherkiwi]

Don't battery builders buying thousands of cells get a whopping discount?

£142 worth of cells, cheap case and low wages for assembly there is still some meat on the bone with an MJ1 base battery at £280.

 

[Nealh]

I haven't seen MJ1's listed for cells in lower cost batteries. Most of the ones sub £200 - 300 all appear to use 22/26F or the marginally better 26H. The higher mah cells like 32E,33G & F1L are pushing the price nearer £300 but you are still only getting low amp (5 - 6.5a) rated cells albeit with greater capacity they don't improve the overall amp rating by much, at best the best of the these cells are only pushing max 26a rating for 4Por 32.5a for 5P a much lower draw then say the PF OR 29E.
The 33G although you would assume is a 3300mah cap cell appear to be at best a 3150mah cell.

 

[Nealh]

Don't battery builders buying thousands of cells get a whopping discount?

£142 worth of cells, cheap case and low wages for assembly there is still some meat on the bone with an MJ1 base battery at £280.

But they want profit so it pays them to buy even cheaper cells in bulk like the 22/26 F or H. For most punters they see a sub £200 battery with Samsung cells even now quite a few at about £165- £180 and are enticed by the price and the knowledge of Samsung inside and that is all they look for, the name and not the quality of the cells within.
Mostly 18 - 24 months of good use before the cells loose some performance.

 

[footpump]

the battery is £245 ebay, £280 amazon I have received a reply from vendor which states we use lg cells 50x 3.4ah but have not got the exact cell info.
have emailed yosepower awaiting reply.

njs I was using 10.4 but had a spare 13ah dolphin battery which I fitted but find range is poor.
I think the 17ah dolphin might have the same battery mounting rail so I can just slot in the new battery , and use the 13ah one vas a spare or back up

the thinking for me is my kudos vita uno 10.4ah battery about 4000 miles now gives about 15 miles of range on the flat/
I would expect 50miles from a 17ah, if the battery after say 2 years gives less range I might still get 25 miles from it and then would consider recelling

I run my tdz at 16 amps would this be too high for the poorer quality cells seems ok w2ith my yosepower 10.4

 

[NJS]

njs I was using 10.4 but had a spare 13ah dolphin battery which I fitted but find range is poor.
I think the 17ah dolphin might have the same battery mounting rail so I can just slot in the new battery , and use the 13ah one vas a spare or back up

the thinking for me is my kudos vita uno 10.4ah battery about 4000 miles now gives about 15 miles of range on the flat/
I would expect 50miles from a 17ah, if the battery after say 2 years gives less range I might still get 25 miles from it and then would consider recelling

I run my tdz at 16 amps would this be too high for the poorer quality cells seems ok w2ith my yosepower 10.4

I think if you paralleled the two, it would give you better range; make your new one last longer; and get some more life out of your old one that might be lost forever if you left it sitting in the garage. That's a win-win-win in my view.

AFAIK, it would only take a short length of cable and a couple of plugs to connect them together; and even if you don't have a suitable second bottle mount for it, it would not be hard to make bag to hang it from the back of your saddle.

 

[anotherkiwi]

I think if you paralleled the two, it would give you better range; make your new one last longer; and get some more life out of your old one that might be lost forever if you left it sitting in the garage. That's a win-win-win in my view.

AFAIK, it would only take a short length of cable and a couple of plugs to connect them together; and even if you don't have a suitable second bottle mount for it, it would not be hard to make bag to hang it from the back of your saddle.

And a meter to make sure they are at the same voltage before plugging them in parallel. Unless you like smoke...

Lucky me, my tired Li-Ion 10.4 Ah only charges up to about 41.5v now and that is what I charge my LiPo to as well!

 

[NJS]

And a meter to make sure they are at the same voltage before plugging them in parallel. Unless you like smoke...

A very good point!

(As they're both 10s packs, if he uses the same charger set to the same cutoff, they should be close.)

Lucky me, my tired Li-Ion 10.4 Ah only charges up to about 41.5v now

My understanding is that 41.5V is the best charge voltage for a 10s li-ion battery even when the cells are new; it's where I'm charging to anyway.

 

[Deleted member 4366]

42.0v is the correct charge voltage for an ebike 36v lithium battery unless it's a LiFePO4 one, in which case it's 43.8v.

 

[Nealh]

My understanding is that 41.5V is the best charge voltage for a 10s li-ion battery even when the cells are new; it's where I'm charging to anyway.

Be careful that cell strings don't get out of balance at 41.5v, every so often you should give a full voltage charge to ensure they are all behaving.

 

[NJS]

42.0v is the correct charge voltage for an ebike 36v lithium battery unless it's a LiFePO4 one, in which case it's 43.8v.

Correct for a full 100% charge I know; but I've read from reliable sources that pack lifetimes can be greatly extended by charging to less than 100%.

 

[anotherkiwi]

Correct for a full 100% charge I know; but I've read from reliable sources that pack lifetimes can be greatly extended by charging to less than 100%.

Because they are charged with specialized chargers and BMS that balance to a lower voltage as in the case of Tesla. On a bike you will get better battery life by using a much larger battery capable of higher discharge rates than those demanded by your motor and controller. For example:

- My 10.4 Ah battery was damaged by regularly using it at 100% discharge for 10-12 minutes at a time - a 3.4 km hill one way 2.8 km the other - with up to 15% gradient.
- If I add a 10 Ah LiPo battery in parallel it doesn't blink an eyelash on the same route, even in its very tired present state.
- The 10 Ah LiPo on its own has no problems there either because I am only using it at about 40% discharge*. The complete 20 Ah LiPo battery is only used at 20% discharge*.

* I am not using the C rate printed on the packaging, quality LiPo gives in reality about 25% of that C rate in real life, lower quality packs about 20% according to the R/C forums I have read.

 

[Deleted member 4366]

Correct for a full 100% charge I know; but I've read from reliable sources that pack lifetimes can be greatly extended by charging to less than 100%.

Some lithium batteries can, but not yours. You're more likely to reduce the capacity by under-charging. Balancing is done between 42v and 41.5v, so if you don't charge past 41.5v, balancing will be compromised and capacity will go down.

This is a case where information is relevant in one context, but it gets misunderstood and regurgitated into a context where it's not relevant, so your "reliable sources" may or may not be as reliable as you thought, depending on which context they're referring to.

Whoever made your bike, decided on a specific charging system to optimise your battery. If there were a way to do it better, they would have provided it.