Kalkhoff Aquttu New Electric bicycle..worried about battery performance.

[kittytwister]

I recently bought two new Agattu bicycles for my wife and myself. Feel we were fairly treated by the seller and also I find the bicycle to ride is just a joy with the assistance of the battery makes life and the journey so much more pleasant. We are both retired and look forward to many trips throughout the countryside and beyond.
I have a major worry and I bought these bicycles because I saw that one could travel up to 140 km on a single charge....there is a label on the 18AH battery to that effect. Well I understand like a car dealer telling you that a car will do so many miles per gallon, you will rarely reach it in reality. My seller advised me for the first three charges to let the battery fully discharge. On the second charge now but find in reality that the journey I can take on a full charge is not more that 33% of that 140 km and this is a cause of concern as batteries appear to be so expensive. Perhaps I am being too concerned. Now I am not riding up major hills and have tried to reduce the setting to low power (one light) on the bar but find that the batteries three lights dissapear far too soon. A rough guide was that after about 12-15 km of normal cycling one light goes off. So that leaves 45 km per charge. Now I have reduced the gears so I am peddling more but would very much indeed appreciate some help and advice from any member of the forum. I have to say I have no gripe with either the retailer or the bicycle which I love. My wife has not got a chance yet to try cycle hers.

 

[flecc]

In my 70s I've had no difficulty reaching 30 miles/48 kilometres on an Agattu with the 10 Ah battery, so your 46 km maximum on the 18 Ah battery is extremely low. I'd suggest you get your wife's bike into service asap to check the battery range on that one.

The 140 km claim is like most manufacturer's range and mpg claims very much a best circumstances one, I'd suggest 80 to 90 km is more realistic for most people from the 18 Ah battery.

 

[Scottyf]

Depends how many Watts per mile you get. This is a more accurate way of knowing what range you will have.
The lights as indicators are usually not that accurate. As your battery is 36v x 18ah thats a whopping great 648watts or useable power.

Given that most pedelec bikes are around the 10 to 15wh per mile usuage that should give you a 43mile range at worst. If you pedal loads and have a low assist I reckon you can get that down to 8watts per mile. This in theory would give you 81 mile range.

Range is anyones guess with these things. Its dependable on so many things - your speed, the terrain, the amount of head wind you get.

On a 250w hub I'd get it down to 6wh per mile. however on my larger setup it eats up 20wh per mile. (And i'm only travelling 6mph quicker).

Most batteries need a few cycles on them to bring them up to their full capacity. Think of it as buying a new car and honing in the engine. The more you use it at set rpm intervals the better the process will be. The same goes with the cells a couple of full discharge and recharge cycles at low use will see them balance and hopefully increase capacity to full.

Either way the 18ah battery is a large battery that should last I would imagine 3 years given its size. It also reduces the motors amp draw on the cells lowering the C rate. This helps the life of the cells also.

Regards
Scott

 

[kittytwister]

Would like to thank the above members for their assistance and advice. Yes its true I suppose one will not get the full 140km. I also keep the battery in a garage adjoining the house and its never more than 10C at the moment so that could have a bearing on the result I have. Really have to say that the Agattu is comfortable and cannot wait for the brighter days when one can head off through the countryside. I do wish that the battery aspect could be a little clearer. Thanks again. M.

 

[Scottyf]

Dont feel bad about the batteries range. You can always add another if you really need those extra few miles. Either way I'd imagine an 18ah battery should give you a huge range compared to most 36v 10ah batteries (@ 360w, you have almost double that).
You've got a good quality bike with proven parts and service. Ok the replacment cost will be hideous but there are ways round this.

I personally wouldn't want to travel more than 40 miles in one sitting on a bike to be honest and I'm average build at 26 years old. But doing that kind of mileage unless in ideal conditions scares me to be honest.

 

[carpetbagger]

With my 18a battery over mixed terrain and using low and medium power i generally get
1st light 14 miles
2nd light 20miles
3rd light 18 miles
flashing 14 miles
My Agattu is modified so you should get more. It seems a strange sequence but that is generally what i get,but a strong headwind can knock a couple of miles off these figures.

 

[NRG]

140Km for the 18Ah battery is extremely optimistic. The best Wh consumption I've managed on my PCS is 6Wh / mile thats with a lot of input from me and only used on the lowest power setting. My typical consumption is 8Wh so given the full capacity of the battery I'd expect range to be nearer 90Km on low assist...much less on high assist.

BTW Scott these batteries are 25.2v not 36....