Thorpy's Guide to Buying an EBike Battery

Thorpy's Guide to Buying an EBike Battery - Intro

There is only one thing worse than shopping for shoes with your wife or girlfriend, and that is buying an ebike battery. The variety of shops to buy from is large with branded systems (think Bosch) costing a small fortune, and cheaper "brand x" (i.e. unbranded) batteries still costing a painful amount but having no warrantee or support of any kind.

So what to do? I have been looking at batteries for around 2 weeks on and off, and I have found the choice a difficult one to make, mainly because lithium batteries are so expensive, and I am not used to spending that much money on bicycle components.

A good lithium based battery can cost upwards of £250 ($400), even if purchased direct from China, so its worth taking time to consider. Expect to pay a minimum of £300 for a quality battery purchased in the UK.

Thorpy's Guide to Buying an EBike Battery - Capacity (AH)

Summary: Bigger is Better

The capacity of a battery (think range or size of fuel tank) is normally given in Amp Hours (AH), typically the bigger the capacity of an ebike battery the more you pay. But before you spend a fortune on getting the biggest battery you can find it is worth considering how far you need to go.

Luckily for us somebody have developed an ebike range calculator for using to determine capacity required. Just fill in the boxes, and you will arrive at your required AH capacity. For me that was 15 AH.

This required capacity relates to a 48 volt system. If you did the same journey with a 24volt system you may require double the capacity.

I am not too hot with electronics so just use the calculator and you will soon realize what is going on!

Thorpy's Guide to Buying an EBike Battery - Voltage (V)

Summary: Must Match Existing if Replacing - Choose 48v if building from New

As mentioned above if you run a lower voltage you will require a higher capacity battery to travel the same distance, this is because a lower voltage ebike motor will use more amps, than a higher voltage motor to do the same amount of work.

A low voltage motor is probably OK in  flat areas where is does not have to work very hard, but if you require lots of power for hill climbing etc. the current flowing through a low voltage hub may damage the motor. The lower the voltage the higher the current needs to be to provide the same energy to the motor.

For example my 24v 500w motor draws 30A when climbing. The wires get warm, the motor is hot to touch. If you consider a vacuum cleaner runs on 13A or less, we can start to see that a high power motor at a low voltage is not very practical.

So if like me you wish to travel 20 miles over hilly terrain you will likely need a 15 AH battery if you are running a 48 volt system, but 30 AH if you are running a 24 volt system.

If you are building bike from scratch you can choose whichever voltage you think suits best (36v is the most widely used), 48v  for heavy going.

If you are replacing a battery you will have to stick to the same voltage, although some good quality motors can be run at higher voltages. But without getting too technical, just replace with a battery of the same voltage.

A final word. It does not do a battery any good to run it down to flat every time you use it. So buy a battery a little bigger then you need. For Sealed Lead Acid Batteries you should only use half of the marked capacity! For most lithium batteries 80% - 90% is OK. Yet another reason why lithium batteries are so much better for ebikes.

Thorpy's Guide to Buying an EBike Battery - Types of Battery (Chemistry)

Summary: For Reliability Choose LiFePo4

Most ebike use some type of lithium battery. Lithium batteries hold lots of power for their size. Although if you are on a very tight budget you might consider sealed lead acid batteries, but these are very heavy.

For proven track record a "LiFePo4" Lithium Battery will be your best bet, although there is now a growing number of  "NMC" Lithium Batteries coming on the scene. These "NMC" batteries are lighter although they are likely less reliable over longer time periods.

Thorpy's Guide to Buying an EBike Battery - Manufacturers (Brands)

Summary: For Value Choose Samsung for Reparability Choose Headway

If you are buying an ebike battery choose known manufacturers. To be clear this is not for the battery itself, it is the "cells" within the battery.

As above; a battery is composed of many small cells, and you should choose a known manufacturer. For example you might find the battery described as 48v 10ah Samsung. If the battery does not include a known manufacturer in the description then it is probably made with cheap no name cells that may not last very long (although you might be lucky!). Look for:

• Samsung
• Sony
• Panasonic
• Headway

Most cells are 18650 type this number relates to the shape of the cell. We are used to describing cells as AA or AAA or even (gasp) LR6. 18650 fits in with these names. 

Thorpy's Guide to Buying an EBike Battery - Output (A)

Summary: Divide the motor wattage by the voltage and multiply by 2.5 for required.

You should check the battery's output is OK for your motor. We are looking for an Amps (e.g. 30A) figure here. A normal 24v 250w motor should draw about 10A, but in reality this could be as high as 15A. For a rule of thumb divide the wattage by the voltage and multiply by 2.5. Then you will never be disappointed. 

It is the continuous or 10min peak amperage you should be looking for. 

The output of a lithium battery is largely determined by the BMS (battery management system), most modern lithium batteries can put out massive currents (amps), so it is the BMS  (the small computer that controls the charging and discharging (output)) from the batteries that is the controlling factor here. 

Sealed lead acid batteries do not require BMS. 

Thorpy's Guide to Buying an EBike Battery - Where to Buy

Summary: Anywhere you like just make sure cells are branded. 

I have not included non branded cells in my search. If you are going to spend a lot of money on a battery then buy something good, that will last (hopefully).

BMS Battery - Sell some batteries made with branded cells, but others are not branded.

Green Bike Kit - Sell some good quality batteries (Headway - £300 for 48V 10AH plus shipping).

AliExpress - Search for branded cells only.  So this page shows a seller who has some samsung celled batteries for sale (£300 for 48V 20AH). Just be sure to read the description carefully.

Eclipse Bikes - Sell good quality batteries based on headway (£500 48v 15AH) & samsung (£300 for 11AH) cells.  The headway batteries they cells can be repaired and have cells replaced easily. Eclipse bike also offer a repair service.

Thorpy's Guide to Buying an EBike Battery - DIY or Bodge Up

Summary: Make Do and Mend for Savings and Satisfaction 

If you do not like spending money and have spare time do some research. You can build your own battery! Or you may be able to repair the one you have. For example a poor quality battery may be filled with 18650 cells which you may be able to replace. You could re-use the case or the BMS at the very least. 

If in my case you are swapping from a 24V to 48V system, can you use a step - up - transformer. To change 24v to 48v. Although you will need a transformer capable of handling high amperages, and a high amperage battery to account for step down in current. I may try this as this costs £18 insted of £300!

Thorpy's Guide to Buying an EBike Battery - Physical Size

Summary: Make sure it fits!

All bikes have limited space where a battery can be placed. For typical bike you are limited to a "bottle" type battery or one that fit on the rack at the rear of the bike.

Just be sure to check the battery you are getting for it size. Measure you bike to make sure it will fit, and that you have the correct mounting points.

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Vitamin C Content of Fruit Juices

Vitamin C Content of Fruit Juices - Intro

Although you can find out various Vitamin C Contents for Fruit Juices, on different web pages, there is no single place where you can compare a good number of differenet juices. Please find below table which I hope is handy.

Vitamin C Content of Fruit Juices - Comparison

All the below are based on 100ml of juice. A normal glass holds about 200ml, a pint is roughly 550ml. A typical serving size would be 200 ml.

Orange Juice - 50 mg

Apple Juice - 0.9 mg

Pineapple Juice - 44 mg

Tomato Juice - 18 mg

Grapefruit Juice - 38 mg

Cranberry Juice -  9.3 mg

Vitamin C Content of Fruit Juices - Longer List 

Orange juice, frozen concentrate, unsweetened, undiluted -137.9
White guava, frozen pulp  - 136.0
Red guava, frozen pulp - 56.0
Grapefruit juice, white, frozen concentrate, unsweetened, undiluted - 119.8
Papaya raw -  61.8
Orange juice, raw - 50.0
Pineapple and grapefruit juice drink, canned - 46.0
Lemon juice, raw - 46.0
Cranberry juice cocktail, bottled - 42.3
Grapefruit juice, pink and white, raw - 38.0
Orange juice, canned, unsweetened - 34.4
Orange juice, chilled, includes from concentrate - 32.9
Grape drink, canned  - 31.4
Grapefruit juice, white, canned, unsweetened - 29.2
Mango raw-  27.7
Lemon juice, canned or bottled - 24.8
Pineapple and orange juice drink, canned - 22.5
Tangerine juice, canned, sweetened-  22.0
Apricot raw - 10.0
Pineapple juice, canned, unsweetened, without added ascorbic acid - -10.0
Kiwi raw - 9.3
Lime juice, canned or bottled, unsweetened - 6.4
Passion fruit frozen pulp - 4.3
Prune juice, canned - 4.1
Apple juice, canned or bottled, unsweetened, without added ascorbic acid - 0.9

Vitamin C Content of Fruit Juices - References

Self Nutrition Data 

USDA

Wikipedia 

Effect of Dissolved Oxygen 

Vitamin C Content of Fruit Juices - Conclusion

It would appear that orange juice has the most vitamin c out of the commonly drank juices. It is worth pointing out that the peel of the orange that we usually throw away contains 136 mg, and if the fruit is organic is perfectly OK to eat if chewed well.

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Fastest CPU for XW6400 and XW8400

Fastest CPU for XW6400 and XW8400

Whilst on ebay a week or so ago I noticed that there were some used processors for sale that I might try in my XW8400.

This page might also be interesting if you have a Max Pro 2, as these use the same generation of processors as the XW8400, also the Dell Precision 490. However I do not own a Mac or  Dell!

In the quick specs document, the XW8400 and the XW6400 are shown as using:

• Intel Xeon 5100 Series 
• Intel Xeon 5300 Series

At present I am using 5160 which is a 3 GHZ , 1333 FSB, 4 MB, 771 Processor

52XX (5200) and 54XX (5400) Series CPUs in XW8400 and XW6400

Since the release of my XW8400, HP have launched the XW8600, and its little sister XW6600.

These use the processor families (THEY DO NOT WORK):

•  Intel Xeon 5200 Series
• Intel Xeon 5400 Series

Now the faster of these newer processors use a 1600FSB which I thought might cause problems, if I were to try it on my XW8400. But some of the newer processors use a 1333FSB. So I thought I would try one of those.

The cheapest I could find on ebay that would have improved performance on my machine was the X5260, which is a 3.33 GHZ , 1333 FSB, 6 MB, 771 Processor. I bought 2 for £5 each so throw away money really.

THEY DO NOT WORK. I tried both just to make sure and the machine will not start, I replaced the original processors and she booted. So that is a shame no upgrades for me. I would 99% assume therefore that all 5200 series processor will not work. And I would 95% assume that all 5400 processors will not work.

So what are the fastest Xeons for the XW8400 and XW6400?

So to conclude the fastest processors for the XW8400 and XW6400 are:

• Dual Core - 5160
• Quad Core - X5365 

BUT BUT BUT What is this I see? HP mention a processor - Xeon 5170 at 3.33GHZ . . .  .

Well it is not listed on the Intel website so rather disappointingly this is either a typo, or a ghost CPU!

Thorpy's Recommendation

If you are undertaking very CPU intensive operations such as video rendering or such like, then it may be worth getting quad core processors. However, the XW8400 at least works very well with a 5160 processor. This is very noticeable when doing normal computer use (opening and closing apps etc.) A 5160 can be had cheaply on ebay as can a heat sink.

If you are thinking of installing one quad core, I would recommend installing 2 dual cores. This will not only be cheaper, but it will help cooling. You will spread the heat load over two heatsinks.

I have not tried the 5365 (quad 3.0ghz) processor, but I have tried the 2.66 ghz 5355. I found them to be noticable slower during open cloase working, and they run much hotter. In fact I think I burnt out a mother board on one of my xw8400's due to over heating*.

*Rebuilding 16GB outlook data base unattended, on a hot summers day with non-standard low noise CPU fan.. . . your choice. 


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NVS 285 vs NVS 300

NVS 285 vs NVS 300 - Intro

I couldn't find a straight comparison of the NVS 285 vs NVS 300 on the web so have made this page.

NVS 285 vs NVS 300 - Bench Marks 

www.videocardbenchmark.net gives rating of 34 and 196 to the NVS 285 and  NVS 300 respectively.

NVS 285 - (From PassMark)

NVS 300

NVS 285 vs NVS 300 - Compared

Feature	NVS 285	NVS 300
Bus Interface Memory Size Memory Interface Memory Bandwidth MEmory Speed CUDA Processor Cores Display Connectors OpenGL Power and Cooling	PCI-Express 128MB DDR 64-bit 4.4 GB/s 350MHz NA 2 21 Watts (Passive)	PCI Express x16 PCI Express x1 512MB DDR3 64-bit 12.6 GB/s 16 2 3.3 17.5 Watts (Passive)
Picture
Video		Sunlight and Daylight Assessment

Thorpy's Guide to Bicycle Sidecars

Thorpy's Guide to Bicycle Sidecars - Intro

This sidecar project is a follow on from my DIY Long Tail Ebike which I think was nor very reliable of useful. The main problem was the drive system, where the rear sprokets kept coming undone during use owing to a reversed thread.

Sidecar for Bicycle. Mixed Results.

So how to get around this? At present I have the pedal chain and the motor chain driving two sides of a flip flop hub, so one thread in the wrong way around. By adding a second driven wheel to the sidecar perhaps this would fix things. No it won't. But I present my findings anyhow.

Thorpy's Guide to Bicycle Sidecars - Research Summary

I know nothing of sidecars, so I did a bit of read on the web first the main thing to realise is that a bicycle side car will need to hinged. Other wise you bike will probably fall over going around corners. A sidecar on the left of the bike for example that is not hinged will result in rubbish left hand cornering, as you will not be able to lean in to the corner.

The only non hinged bicycle sidecars that you see are either the BMX racing ones (where the sidecar is presumed to weighed down with a human whilst riding) or the taxi type things they have in the Philippines (which are named after King Philip of Spain by the way).

So in short unless you side car is heavy or permanently loaded then you will need a hinge.

Thorpy's Guide to Bicycle Sidecars - Motor Driven Wheel on Sidecar

So with nothing but I skewed common sense to guide me I built the side car, welded it on, use some heavy door hinges (steel not brass!) I mounted the motor and went for a test drive.

Note Mounting Plate for Motor

The result. With a hinged sidecar there is not enough down pressure on the wheel to create adequate traction. Of course when loaded this would work OK, so if you had you side car mounted with big heavy seat or a heavey wooden box, this approach may work. It didn't for me.

Thorpy's Guide to Bicycle Sidecars - In Use

So since this first failed attempt I have switched the motor on to the front wheel to make a front wheel drive chain driven ebike. This has proved a really good move, and I now have a reliable drive system. But I thought I would test out how usefull the sidecar was being I had gone to the trouble of making it.

So apart from the extra width when empty you would not even know the side car was there, the bike corners as normal, and when the hinges move the tire moves in and out from the bike  slightly, which you think would be noticable but whilst moving it isn't.

Right Hand View

BUT what about when you load up the sidecar? Oh dear. I put 50 kg - 60 kg of logs in sacks in the sidecar, and things went wrong. Now there is a greater deal of pressure on the sidecar wheel, and as a result the friction with the road is greater, the hing effect is now very "sticky" and this had some "interesting" effects on steering.

Hinges

Hinges

Something that is also perhaps a bit dangerous is that when you turn right the cargo bed widens, and loose sacks of say logs, will slump down in to this new widened space, and you will not be able to get the bike upright.

The ONE thing that is good, is that the bike will stay upright when you are loading it, although you have to be careful not to knock it over.

Thorpy's Guide to Bicycle Sidecars - Recommendations

Some really big spring in stead of hinges might be an idea. So you bend when going around the corner, and the hinging effect is limited.

I have seen design with a stabalising bar that you can use when loaded, and take off when empty. Best of both worlds.

Side Car Size Based on Euro Crate Size 400 x 600mm

Rear Dropouts Made from Plate Steel

 A side car seems to bring all of the disadvantages of a car, with all of the limitation of a bike. So Is not really very good. It would be OK for large light loads, but so would any long tail cargo bike + ratchet straps.


A sidecar would be useful for a permanently loaded application such as a rickshaw with heavy seat and canopy, or perhaps some sort of micro coffee kiosk. But for the occasional /one way cargo carrier it represents a world of confusion.

I will be hack-sawing this off in the next few days.


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Schwalbe Jumpin Jack Tyre Review

Schwalbe Jumpin Jack Review

These are a very knobbly offering from Schwalbe that come in a 2.1 or 2.25 size. Both 20".

These are pictures of the 2,25" size and they are evidently sweet.

Big Knobbles . .

. . . more Big Knobbles

These tyres have a funny little raised bit that sits against the rim, this might be there to help prevent pinch flats / snakebites but not sure. This means fitting the tyres are a bit more tricky especially on "taller" rims. These are on gusseet rims, and they were a tight-ish fit. i.e. I needed levers.

Unlike Dirty Harrys (another tyre by Schwalbe) these tyre do not have a puncture protection belt. I am running them with tyre liners.

Cheap if bought from Germany <£10.  Try Bike Parts De


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Chain Driven Front Wheel Drive Ebike

Chain Driven Front Wheel Drive Ebike - Why?

If you are trying to do an ebike on the cheap then you might be a bit resistant to the thought of spending £200 on a Chinese no name hub motor, with lots of plasticy control and unessassary electronics.

This is why I purchased a chain drive motor, it was about a third of the price of a cheap hub motor. In fact I got everything I needed to electrify my bike for £180 including batteries (Panasonic Batteries!).

Be Prepared for Ugly

The result is a dog ugly bicycle that I know I can get parts for if they go wrong becuase I bought all of them individually.

Chain Driven Front Wheel Drive Ebike - How

You will need the motor. Unite Motor Company make lots of different electric motors. You will need one that is geared down for torque.

You will need to mount the motor above the tire quite high up, where it will not stick out too much. Or you can mount is sticking out of the side lower down, which make the bike less wobbly (lower centre of gravity).

BMX Rear hubs are 110mm OLD, i.e. the drop out are 110mm spacing. Front forks are 100mm spacing so you do not need to widen them much to fit in a BMX rear hub.

In my case I sawed off the drop out on the left hand side (right hand side in pictures) and welded back on. This was an easy job as you can use the axle to hold everything in place. Just be sure to warp some tape around the axle to stop the weld blobs sticking to it.

Note Re-positioned LH Drop Out (Right Hand in Picture)

Being you have just misaligned the drop out the wheel will not sit centrally in the forks so you will have to dish the wheel a little more so that the rim comes back to centre. You will need a spoke key to do this.

Plate Welded on to forks

The plate will need to be quite thick, even a small motor will flex a thin plate, a diagonal support to the rear will help keep things ridgid. Mark the holes for the bolt carefully, and lengthen the hole with a file so you can slide the motor away from the motor to tension the chain. Nyloc nuts are advisable.

This is so much simpler than trying to fit a chain driven motor to your rear wheel, whilst keeping the pedals. If you are running a low voltage (24v) system like this one here you will need fat wires to avoid reistsance as the wires will have to run from the back of the bike to the front, which in this case is about 1.5 meters.

To look at the whole bike, please visit my DIY Long Tail E Bike Page

Close-up of left hand drop out.

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Illustrator Devon