Battery mounting and other questions.

[drillam]

Hiya
Well I joined and posted my introductory mail on the appropriate thread so here's my first couple of questions.
Firstly I'm very new to bicycles and pedelecs so please forgive my ignorance.

I'm just about to take the plunge and order a conversion kit for my mountain bike, this bike, barley ridden until last week although owned for a couple of years-

I'm buying a 48v 1000w rear wheel kit and have decided on 2 x 20aH Lifepo batteries.

This is the kit:-

48v 1000w Rear Electric Scooter conversion Kits E bike on eBay (end time 29-May-10 05:22:04 BST)

and these are the batteries:-

48V 20AH LiFePO4 Battery Electric Scooter E Bike Safe on eBay (end time 28-Apr-10 07:30:04 BST)


I'd like to mount the batteries low down at the rear, straddling the wheel to keep the weight low. Would something like this be strong enough?

Bicycle Rear Rack attaches to Saddle post on eBay (end time 01-May-10 11:57:35 BST)


Next I'd like a sturdy, waterproof, secure method of attachment and was thinking of lockable ABS type panniers. Like a smaller version of the kinda thing I used to use on my motorbikes.
Does anyone know of a scource for these? or another method?

Is it best to connect both batteries is parrallel or run one down first then switch to the second when it's exhausted?

My personal weight is around 200 pounds, no I'm not a fat sod I'm just 6'6" tall. So I'm estimating the weight of bike, kit, batteries etc and myself combined will be around 300 lbs. My son who's bigger and heavier cycled John O Groats - Land's End some years back and tells me his normal tyres kept bursting under his weight and he had to get special road type tyres.
However I'd like to retain the off road mountain bike type for gentle tracks and suchlike.
What would be your recomendations in this respect?
Many more questions to follow.
Thanks in advance for any advice.
regards
Drillam

 

[Psycosis]

The only thing i can say is i looked around for batteries and i finally decided on getting a battery from PingBattery LiFePO4 Battery packs for Electric Bicycle e-Bike & Scooter, Lithium Iron Phosphate Battery mainly because they are a fair bit lighter. His 20ah batteries weigh in at 9.9KG, vs 12.5KG for the v-power batteries.

There is also the size issue, i think i looked at the v-power batteries and they will just about fit in a pannier, i have someone measure with a shoe box that was the same size.

 

[NRG]

Those batteries show as 12.5Kg! It going to be hard enough mounting one let alone two!. You have a full suspension bike, how are you going to lock the rear so you can fit a rack to take the weight? The rack you linked is not going to take 25Kg hung from the seatpost....

300lb I make that 136Kg and 45Kg for the bike double

 

[drillam]

Phsyco, NRG, thanks for your replies.

Phsyco
I had a look at Ping's batteries and he quoted me over £1,000 including the 5 amp charger and delivery for the two that I wanted.
V-power's batteries and 48v 1000w rear wheel kit are costing me £920.
I realise that you get what you pay for, but my budget is not going to stretch for the very best of everything.

NRG
I just weight the bike and myself.
The bike is 19Kg
Rider is 94.5Kg
Batteries 29Kg

Total so far 142 ish, plus anything else I need to carry.
I'm really more concerned about the tyres than anything else.
The rear supension shock can be binned and a solid link substituted. I can then mount a sprung saddle post for comfort and one of the "presumably" stronger rigid bike frame type rear pannier racks.

I think I found the answer to the pannier question :-
Bicycle Panniers / Bike Bags

Waterproof, secure(ish), and should survive gentlish knocks and stuff at 2.5mm thickness. What do you think?

cheers
Drillam

 

[eddieo]

I am not technical at all but full suspension bikes do not seem a good fit for any e bike project let alone one with the 2 hefty batteries you want to carry How can you fit a rack when the bike has rear suspension?

 

[NRG]

They certainly look the business but will add another 2.6Kg to the overall weight if you are buying two.

How much does the motor / controller / bits n pieces weigh in addition to your figures above?

I appologise for being 'down' on your plans but from my experience having been down the route of heavy motor and batteries I soon realised lighter is better not only from a tyre/rim point of view but also from a handling and braking view. Even with weight lower down the bike will handle poorly especially at the weights proposed and your brakes are going to need upgrading I would have thought.... A 48v 1Kw bike is going to move at a fair old speed (illegally I might add) so stopping power will be paramount for saftey. Also if you break down, it will happen at some point, I hope you'll be able to pedal it all home....

After I fitted a smaller motor and batteries to my Peugeot the bike was transformed, it goes as fast if not faster than before and I have no worries about riding it unassisted, which brings me to ask what do you need such a powerful bike for?

 

[drillam]

I am not technical at all but full suspension bikes do not seem a good fit for any e bike project let alone one with the 2 hefty batteries you want to carry How can you fit a rack when the bike has rear suspension?

Hi Eddie
Like I said above, junk the rear shock absorber and replace it with a solid link - easy enough done.
However as also stated - I'm more concerned about the tyres, and come to think of it the spokes, will they take the weight?

 

[drillam]

They certainly look the business but will add another 2.6Kg to the overall weight if you are buying two.

How much does the motor / controller / bits n pieces weigh in addition to your figures above?

Dunno, I forgot about those

I appologise for being 'down' on your plans

Please don't appologise, I need the weight ( duh,, sorry ) of your combined experience.

A 48v 1Kw bike is going to move at a fair old speed (illegally I might add)

Understood, though speed is not my prime goal, it's range.

which brings me to ask what do you need such a powerful bike for?

Well at close to 95Kg in me birthday suit I wanted something that wouldn't baulk at the first decent gradient it came to.
My goal is a range of around 40 - 50 miles on any gradients I happen accross without having to break into too much of a sweat.

 

[HarryB]

My goal is a range of around 40 - 50 miles on any gradients I happen accross without having to break into too much of a sweat.

You are lucky to have 40-50 miles off road to play with your 1KW bike - have you thought about getting a scooter, electric or otherwise?

 

[eddieo]

You are lucky to have 40-50 miles off road to play with your 1KW bike - have you thought about getting a scooter, electric or otherwise?

probably a criminal, drug fiend or the like and banned from driving? ( this was a joke but e bikes are know "gateway" vehicles in The good old US of A, and used by criminals! lol)

 

[HarryB]

In some states all ebikes are illegal not just the 1kw versions. There was that great clip on YouTube of some guy detained by the police on his way to church. Must dig it out.

 

[Xcytronex]

Try contacting electric mountain bikes, electric bicycle, electric bike kits, folding bicycles for a more positive/useful spin on what you can or can't do with your proposed set- up/budget.I have found these guys quite helpful in the past.

 

[Patrick]

I think I found the answer to the pannier question :-
Bicycle Panniers / Bike Bags

The one problem with bikebins is that their irregular shape and internal fittings make it difficult to fit large rectangular objects in them. I just checked the internal dimensions of my one and you would fit one of the linked batteries (280x140x180mm) in it. So you would need a pair (at 1.3 kg each) plus a rear bike rack capable of carrying 31.4 kg (2*[1.3+14.4]) to mount them on.

Patrick

 

[NRG]

......
My goal is a range of around 40 - 50 miles on any gradients I happen accross without having to break into too much of a sweat.

Well if speed is not a priority you can achieve your aim with a geared brushless 36v 250W motor, 20amp controller and a 20Ah battery

The ping battery weighs just 7.5kg Results for 36V LiFePO4 Battery Packs )

A 20amp controller and 36v battery will give +720w of peak power and if say your average 'fuel consumption' is about 15wh / mile you could get 48 or more miles out of it...all depends on how much effort you put in and how many hills you climb.

I think you could save about 25Kg in weight, battery / motor / panniers etc...