Battery price

[indalo]

Although the battery on my Gazelle has served me well and is still useable for trips up to about 20 miles max if I don't use high power much, I thought I'd price up a replacement. I was more than a little shocked to be told that the cost is now £420 + £10 carriage. Less than 3 years ago, on enquiry, the price was something of the order of £270-£290, certainly under £300.

The dealer explained that the price of my 8Ah battery had risen more than that of the 10Ah model as there isn't much demand any more for the smaller one.

Much as I love that particular bike, common sense demands that I consider writing it off when the battery expires and replacing it with something more powerful with a warranty and less chance of obsolescence in the foreseeable future.

On checking out the cost of Gazelle's latest range of batteries for their Innergy models, they're not exactly giving them away either. It's unlikely I will be able to find another crank-drive bike with fully-enclosed hub brakes and chain plus internal hub gears and dynamo so I have a vast choice at all price points. My other ebike is hub-driven but I don't want another, preferring the sophistication, quietness and control of Panasonic's delightful system. Bosch needs to be considered too of course but I'll put off buying a replacement for as long as possible, such is the rate at which new products are hitting the market.

I do wish David Miall would tell us more about the deal he's been trying to set up involving another brand which he will make available through his dealers. I suspect he might just have something that interests me but we shall see.

Indalo

 

[hech]

Why dont you ask amigafan very very nicely if he could make you up a nice wee lipo pack which would give your old bike a wonderful new lease of life. In a good mood he might only charge you £150 and you would have hours of endless fun learning up about lipo charging solutions?

 

[alfazzr]

I have been reading all that I can about batteries recently, (I currently need a 24 volt) but I have suddenly slipped into a parallel universe - somebody rescue me !

Having just read about Jerry's £20 home made battery pack I came across this. I know it is not in stock and perhaps never will be again, but is this not a great deal ? Unfortunately it is only 22.2 volts.

HobbyKing R/C Hobby Store : Turnigy 5000mAh 6S 20C Lipo Pack

$44 for 5 Ah ? 20C discharge - what a shame they dont do a 7S pack !

I just don't understand battery prices !

 

[tillson]

The price of batteries rose due to the value of the pound falling against the Euro. Unfortunate, but unavoidable I'm afraid.

Hang on a minute, that can't be right. The pound is now strong against the Euro and battery prices haven't come down.

 

[jerrysimon]

Whilst Lipos do have application, please be aware they need to be treated with some respect having quite a flamable chemistry.

Regards

Jerry

 

[hech]

alfazzr you are quite right about the battery enigma. There is a conspiracy of silence regarding lipo, perpetuated by jerry and others from largely good intentions. But if you are looking for the best solution then lipo is definately it!

 

[alfazzr]

I now realise that these do not have a BMS so you need a balance charger. I have found they do sell a 5Ah 7S (25.9v) for $64.98 but I cannot find a charger to do more than 6 cells so I don't know how you would charge that.

I have seen that LiPo is considered dangerous (?) but I recently bought what was described as just a "Lithium" battery to find it is a "LiMn2O4" so was little confised as to whether LiPo is just a generic reference to many chemistry types. Is LiMn2O4 = LiPo ?

 

[hech]

Yup, if they sell a 7s then they will also sell a balance charger capable of charging it. Without a bms you need to keep a close eye on your battery and would certainly require a wattmeter . A three day fire fighting course is also adviseable.

 

[alfazzr]

Ahhhhh, that good eh ?

 

[amigafan2003]

Why dont you ask amigafan very very nicely if he could make you up a nice wee lipo pack which would give your old bike a wonderful new lease of life. In a good mood he might only charge you £150 and you would have hours of endless fun learning up about lipo charging solutions?

Haha - I'd NEVER build a lipo pack for anyone else.

I wouldn't be confident they had the intelligence to use it properly without burning thier house down

I have been reading all that I can about batteries recently, (I currently need a 24 volt) but I have suddenly slipped into a parallel universe - somebody rescue me !

Having just read about Jerry's £20 home made battery pack I came across this. I know it is not in stock and perhaps never will be again, but is this not a great deal ? Unfortunately it is only 22.2 volts.

HobbyKing R/C Hobby Store : Turnigy 5000mAh 6S 20C Lipo Pack

$44 for 5 Ah ? 20C discharge - what a shame they dont do a 7S pack !

I just don't understand battery prices !

I use four of those - two paralled and two in series plus another two 3s 5000mah pack paralleled then seriesed in to make a 63v 10ah pack - that's 590w/h, weighing 3.5kg for a grand total of £180 if you included the connectors/extra cabling.

The other lipo pack is 4 paralleled 2s 2000mah packs for my MagicShine lightset.

But as I said - lipo is not for the faint of heart nor intelectually challenged and it is not an off the shelf, plug and play solution.

 

[muckymits]

Yup, if they sell a 7s then they will also sell a balance charger capable of charging it. Without a bms you need to keep a close eye on your battery and would certainly require a wattmeter . A three day fire fighting course is also adviseable.

Yes they do I have a 8 port Turnigy from them and was cheaper then the 6 from ebay. Its a clever little beastie will almost charge a wet house brick . I always sit mine on the side of an old pc case.

 

[flecc]

I recently bought what was described as just a "Lithium" battery to find it is a "LiMn2O4" so was little confised as to whether LiPo is just a generic reference to many chemistry types. Is LiMn2O4 = LiPo ?

LiPo = lithium polymer. Polymer is just a cell content construction, not a chemistry, so ignore references to LiPo or Polymer, they are rather meaningless and no better than slang having various meanings according to who is using the terms. LiPo can be any of the following.

LiMn is a chemistry, lithium manganese, indicating that the cathode uses manganese. Many with this designation now have compound cathodes using many elements in addition to the manganese. 500 to 1100 charges according to cathode type.

LiFePO4 is also a chemistry, Lithium Iron Phosphate, indicating an iron based cathode, longer lived but heavier and bulkier. 1000 to 3000 charges according to rate of discharge in use, higher discharge (powerful motor) = shorter life.

 

[alfazzr]

Wow Amigafan2003, so that's like this diagram:

Thanks Flecc - so which particular types raise the comments about being fire hazards. I know Jerry (and others) consider LiFePO4 as 'safer'.

 

[amigafan2003]

Wow Amigafan2003, so that's like this diagram:

Yes, spot on

I'm debating adding another two 6s packs and one 3s pack to make 63v15ah pack 900w/hr's

As far as chemistry - the "hobby" lipo packs I'm using are LiCo - Lithium Cobalt - very volatile if mistreated. LiMn is not quite as volatile but still has the potential to release the magic smoke and catch fire if mistreated and then LiFePO4 is the safest of all the lithium chemistries - very resistant to overcharging and over discharging and while you can "pop" them they wont catch fire. They are however twice the weight.

incidently, nearly all "lipo" fires are during the charge statge - mostly after they've been overcharged too much. Punturing them also isn't a good idea!

 

[flecc]

Thanks Flecc - so which particular types raise the comments about being fire hazards.

The fires that really caused alarm with lithium batteries in laptops etc were due to the cobalt cathodes in use in their earlier days, since with cobalt in use poor manufacturing standards could result in internal short circuits, fire and even explosion. Cobalt is no longer used in isolation in e-bike batteries but has been re-introduced in compound cathodes in a safe way now.

Manganese and compound cathode cells can still catch fire if abused, but proper e-bike batteries have management systems (BMS) which prevent that occurrence.

So current problems are really with e-bike batteries home constructed with cells not having any BMS protection during charging or use. The cells used, often referred to as LiPo are usually compound cathode types but equally could be lithium iron phosphate or lithium cobalt. The LiPo term seems to come from the modelling world and I find such generic use less than helpful since it has no relevance to usage.