"Get me Home" Battery

Oldie

Pedelecer
Mar 29, 2013
142
38
Scotland
Does anyone carry a small spare battery (eg 6ah) if planning longer trips, like those ones without a case? Some of my forest track adventures are very hilly and I'm never sure how far my 15ah battery will take me. I was thinking of something small enough to carry in my rear bag to minimise weight but large enough to get me an extra 10 miles or so (250w BBS01B).
 

matthewslack

Esteemed Pedelecer
Nov 26, 2021
1,630
1,208
Does anyone carry a small spare battery (eg 6ah) if planning longer trips, like those ones without a case? Some of my forest track adventures are very hilly and I'm never sure how far my 15ah battery will take me. I was thinking of something small enough to carry in my rear bag to minimise weight but large enough to get me an extra 10 miles or so (250w BBS01B).
Yes, routinely although tends to be another full sized battery, 11.6Ah is my smallest.

It is a great comfort, rather like the 'reserve' position on the fuel tap on my long ago small motorbikes!
 

guerney

Esteemed Pedelecer
Sep 7, 2021
10,245
3,004
6Ah might be too small for hills? When running very low on charge, even my 19.2Ah battery shows a lot of voltage sag, when ascending steep hills. Sputters out. (My BBS01B controller is limited @15A)
 
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StuartsProjects

Esteemed Pedelecer
May 9, 2021
1,694
952
I have taken my smaller 36V 10Ahr as a spare when on long trips.

That battery is a hailong type so directly swappable with the one already on the bike.

Although there are smaller batteries out there, the 4.4Ahr hoverboard batteries for instance, one suspects the voltage sag on hills might cause problems.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
20,134
8,230
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West Sx RH
A decent 6ah battery should get you 20 miles as a get me home type battery in low power assist , though you need to use 20/30a rated cells for a small 2p battery for the lightest option.
 

Bikes4two

Esteemed Pedelecer
Feb 21, 2020
896
398
Havant
Does anyone carry a small spare battery (eg 6ah) if planning longer trips, like those ones without a case?
  • Yes, I do - I run my TSDZ2 250w mostly on ECO assist, so low current draw and as a 'reserve tank' I built a 10s 2p battery using the LG 21700 M50LT costing about £100 or less and I carry it in a small handlebar bag.
  • This gives me around 8.5Ah+ and an extra 40+ miles
  • I am now looking to build either something that I can put inside a standard water bottle or one of the side pockets on my Carradice saddlebag usinf 18650 and something around 5Ah as that's all I really need to supplement my main 10Ah bottle battery.
  • I had toyed with different ideas on how to either run the main and reserve in parallel with or without 'ideal diodes' or some sort of switching arrangement
  • Both necessitate some form of 'bulk' (ie a box for the bits) so at the moment I run several leads into my saddle bag where the motor and battery cables are terminated in XT60 plugs/socket and I use an XT60 male/female pair to just link up which ever battery I need to power the motor- dead simple with less to go wrong and it works well for me.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
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Alan for a small 5ah 18650 any decent cell should be ok, moli 2800 would be a good shout or for the same footprint the moli m35a for 7ah nominal.
If you wanted really cheap one could try the Eve 33v cell for 6.2ah or the Sinowatt 30sp.

Although with 18650 5ah one might as well go with a 3000 /3500mah cell for the extra Ah as the foot print is the same , esp as like me you use eco mode.
 
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vidtek

Esteemed Pedelecer
Mar 29, 2015
412
228
73
Bournemouth BH12
I have never managed to run my battery flat-my sore posterior after 20 miles or so makes me stop!
 
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slowcoach

Pedelecer
Dec 11, 2020
174
115
When I had my Ezee Sprint, I made a bracket to allow me to carry a second battery. The range of this bike was approx 20 - 25 miles on one battery. Having the second one meant I could go for a reasonable ride each day.

Now, with the Raliegh Motus, I find the battery good for about 50 miles. However, age and A Fib have caught up and I can not attempt that sort of distance. 20 miles is now a reasonable ride for me, although I have, on a good day, managed 40.
 

guerney

Esteemed Pedelecer
Sep 7, 2021
10,245
3,004
I have never managed to run my battery flat-my sore posterior after 20 miles or so makes me stop!
I can't find the saddle I use, but it's similar to this cheapo - very comfy for my longest battery exhausting ride ever of 43 miles, when my battery was new. I dropped from 100% of 15A continuous (level 9) for the final couple of miles, but by that stage using 20% of 15A (level 2) didn't make much difference and when it was totally done, I walked the bike uphill, cycled on the flat (a struggle with a BBS01B) a further 6 miles powered by caffeination and blood sugar saturating 24 hour garage stops.


Much comfier than my i-beam razor sharp saddle.
 
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guerney

Esteemed Pedelecer
Sep 7, 2021
10,245
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When I had my Ezee Sprint, I made a bracket to allow me to carry a second battery. The range of this bike was approx 20 - 25 miles on one battery. Having the second one meant I could go for a reasonable ride each day.
My battery is on the rear rack, and there's actually room for two "Shark" batteries side by side... at one point in horrible 2020/21 I was planning 90+ mile rides, but won't be now. I was simply going to unplug one and plug in the other.
 
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Bikes4two

Esteemed Pedelecer
Feb 21, 2020
896
398
Havant
I have never managed to run my battery flat-my sore posterior after 20 miles or so makes me stop!
Ouch - there's nothing worse than a sore butt from cycling - I'm guessing you've tried different saddles although that can be an expensive experiment. I've always got on well with Brookes leather jobbies - torture for some but heaven for others.

Posteriors and saddles are very personal things and some people unfortunately never find a comfortable solution. On the plus side, you won't have to worry about battery range anxiety :rolleyes: .
 
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guerney

Esteemed Pedelecer
Sep 7, 2021
10,245
3,004
I have never managed to run my battery flat-my sore posterior after 20 miles or so makes me stop!
Posteriors and saddles are very personal things and some people unfortunately never find a comfortable solution.
I dip the saddle nose down a lot and sit with my weight resting just on the wide flat part. Weirdly, very comfortable for long rides - my cycling posture is a very aero and determined looking crouched forward, handlebars low, ghost pedalling all the while and chuckling.

Also similar to my saddle:

 
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vidtek

Esteemed Pedelecer
Mar 29, 2015
412
228
73
Bournemouth BH12
I have to sit bolt upright to get any sort of comfort while riding.
I've tried all sorts of saddles, none are really comfortable. In 2015 a mad Muslim woman with 2 children onboard texting her friends rear-ended me while I was stationary at traffic lights. Damaged my coccyx and I struggle now to sit on hard chairs for more than 10 mins and cannot stand for more than 5mins.
Hey at least I'm still vertical, although both cars were scrapped, mine was a very substantial Peugeot 3008 only 2 years old and hers was a 3 week old Xtrail. She hit me so hard that she pushed me into the railings in front of me. 2 police in a patrol car on the opposite side of the street saw it all and sped away as fast as they could so as not to get involved. Luckily umpteen witnesses saw the whole thing but she was never prosecuted...I wonder why that was...
 

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lenny

Esteemed Pedelecer
May 3, 2023
885
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Damaged my coccyx
Broken? Fractured? Misaligned and causing continuing inflammation because compression is pressuring nerves thereby causing pain? Note medical disclaimer on this video. Consult medical professionals or it could get worse.

 
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Nealh

Esteemed Pedelecer
Aug 7, 2014
20,134
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West Sx RH
I use the lidl saddles, 160km is my longest ride.