Kalkhoff Agattu 36v 17AH battery - near Lincoln - HELP NEEDED

[Martin Goodwin]

Hello. I've purchased a 2013 Kalkhoff Agattu 36v 17AH from an auction. Battery seems dead but I want to check the rest of the bike out before spending ££££'s on a new battery. Is there anyone in the Lincoln area with a similar machine that I can 'borrow' the battery (I'll come to yours) to prove the viability of my bike. Many thanks in advance. Martin G.

 

[flecc]

Sorry I can't help with a battery, but you are wise to check it out first. Kalkhoff Agattu's, although good bicycles, around that period were fitted with the Daum Impulse 2 motor which was so notoriously unreliable that it sent the UK Kalkhoff distributor into bankruptcy.

If you show us a side on photo of the bike so we can see the motor outline clearly we'll know what motor it has.
.

 

[Martin Goodwin]

Thanks for coming back to me so quickly. I have managed to coax the battery back to life !! ( watched many clips and read many articles) Used car batteries in series to 'force' a semi charge, then found it would only take a charge from the bottom 'cradle' point. I only have a side charger so I had to rework the internal wiring. I now have 36v of power but the bike isn't acting as I expected it to. I have never ridden an ebike before so don't know what to expect !! It has the 'modification' that brings the sensor from the rear wheel to the pedal crank. I had to fix the sensor but there was no magnet. So I'm now trying a magnet to get that part of the system working. I'll post a couple of photos ASAP but it has the dreaded Impulse motor. What goes wrong with them? I'll strip anything down to repair !! Would its be easier to continue this by email? If you are willing

 

[flecc]

Thanks for coming back to me so quickly. I have managed to coax the battery back to life !! ( watched many clips and read many articles) Used car batteries in series to 'force' a semi charge, then found it would only take a charge from the bottom 'cradle' point. I only have a side charger so I had to rework the internal wiring. I now have 36v of power but the bike isn't acting as I expected it to. I have never ridden an ebike before so don't know what to expect !! It has the 'modification' that brings the sensor from the rear wheel to the pedal crank. I had to fix the sensor but there was no magnet. So I'm now trying a magnet to get that part of the system working. I'll post a couple of photos ASAP but it has the dreaded Impulse motor. What goes wrong with them? I'll strip anything down to repair !! Would its be easier to continue this by email? If you are willing

Best keep it in the forum since others can contribute as well Martin. The Impulse motors suffered amongst other things from the pawls in the chainwheel's freewheel disintegrating and occasional failures of the nylon toothed reduction gear. Getting spares is a problem since Kalklhoff and the parent company in Germany, Derby Cycles gmbh are uncommunicative.

However, the following specialist company can often help with repair and refurbishment and members have found they give an excellent service:

eBike Motor Repairs & Servicing - Homepage

eBike Motor Parts Repairs & Servicing, (formally, Performance Line Bearings) has become the “go to place” for all your e-Bike motor repairs...

www.ebikemotorcentre.com

.

 

[Nealh]

36v is only the battery nominal voltage and this approx. 40% capacity, it should charge to 42v max but anywhere between 41.5v - 42v is good. I would rejig the wiring as original and try the charger now it has some life to see if it might balance charge.
Other wise as you have had the battery open, one will need to check the 10 individual cell groups for balance to see if there is an issue.
Reverse charging is never and ideal situation and bypasses the BMS's safety features.

 

[Martin Goodwin]

Thanks for the info. I'm learning and the info is great thanks. The BMS would not allow any charge from the 'top' connections, only when I connected to the 'bottom' connectors. Is that not the same as when it's in a charging cradle? (which I don't have)...... I'll check accurately the 10 cells over lunchtime

 

[Martin Goodwin]

40.3v overall
7 X 3.97, 1 X 3.98, 2 X 4.13 1 cell has a detached spot weld (just noticed it)
Would it help if I discharged it a few times?

 

[Nealh]

When the BMS doesn't charge it could be that it is in sleep mode as some batteries BMS have this mode.
Often the refusal to charge can be because of a low cell group voltage, the BMS has an LVC (low voltage cut off) and if any one cell group is at or below this threshold it simply won't allow charging as it senses a fault. One reason why I always ask someone to check all the individual cell groups first as one poorly one will prevent charging.
The bottom reverse charging can lead to a cell group over charging if all groups aren't monitored an over charged cell group could cause a fire or a short and may well kill the battery.

 

[Nealh]

40.3v overall
7 X 3.97, 1 X 3.98, 2 X 4.13 1 cell has a detached spot weld (just noticed it)
Would it help if I discharged it a few times?

The battery is quite unbalanced a BMS won't balance it in one go and may take several charge discharges to balance up a bit better when repaired.

Is it an actual cell can connector or a sense wire ?

If a cell has a detached spot weld, it will cause an issue due to intermittent contact and unbalance. It will be make the other cells in the same group work harder and stress them more and affect the voltage flow from or to the adj cell group.
If one has no access to a spot welder one could try soldering the weld to the can top/base.
Show us a pic.

 

[Martin Goodwin]

Watchmakers behind the spot weld

 

[Nealh]

Naughty & bad practice using a metal tool, one should use a non conductive one.
Those cells have either leaked or have seen water ingress, not surprised the welds have failed. Rusting will mean the conductive connection is also poor.
At 9 yrs old it is time for a new battery/re-cell.

 

[Martin Goodwin]

Again thanks. Bad practice telling off duly noted I shan't tell you I shorted out whilst testing the checks then Quite impressive I have to say. On a serious note, I took the impulse motor to bits last night. Bearings and teeth all OK. The sprag ? clutch arms were seized and semi seized so I cleaned them off. Re-assembled without much lubrication or case sealant (want to see if it all works first). I have yet to put it back in the frame. The Kalkhoff batteries are extremely expensive (a recell is circa £500), is there an issue (apart from quality) with purchasing a similar frame mounted battery pack and slaving it in to the bike? I know the additional wires go to the BMS but I do not know their function. Again thanks for all this brilliant advice.

 

[wheeliepete]

Unfortunately you cannot use a 3rd party/generic battery with the Impulse 2 motor. The extra wires on the BMS are for comms. between the motor/controller and the battery pack. I would think very carefully before spending £500 on a new battery, shame because the bikes are great quality, but that motor is too unpredictable. Wear is not always an indication of workability with this one, people have suffered motor failure within a few hundred miles. Deff. worth having a word with Peter at https://www.ebikemotorcentre.com/ who will have worked on a few of these motors and I'm sure would share his experience with you.

 

[Martin Goodwin]

Thanks. Good steer again. I'll talk with Peter about the viability of this project. Cheers

 

[Martin Goodwin]

If you were to buy second hand what make / model would you be looking at ? Looking at a daily commuter, up to 12 miles each way. Thanks

 

[flecc]

If you were to buy second hand what make / model would you be looking at ? Looking at a daily commuter, up to 12 miles each way. Thanks

Chinese, preferably hub motor bike, since they are simple and easy for someone with your abilities to repair with easily available generic parts, including reasonably priced replacement generic batteries. Preferably aim for an established make known for good service although that's not vital with such e-bikes.

You can even buy new at quite low prices from such as Woosh who are highly thought of by us with staff members in here giving good service:

Woosh Electric Bikes

Note though that supplies are very short at present for the obvious reasons.
.

 

[USAebike]

Best keep it in the forum since others can contribute as well Martin. The Impulse motors suffered amongst other things from the pawls in the chainwheel's freewheel disintegrating and occasional failures of the nylon toothed reduction gear. Getting spares is a problem since Kalklhoff and the parent company in Germany, Derby Cycles gmbh are uncommunicative.

However, the following specialist company can often help with repair and refurbishment and members have found they give an excellent service:

eBike Motor Repairs & Servicing - Homepage

eBike Motor Parts Repairs & Servicing, (formally, Performance Line Bearings) has become the “go to place” for all your e-Bike motor repairs...

www.ebikemotorcentre.com

.

In the USA these motors are rebuilt with no problem for $300 USD.

 

[flecc]

In the USA these motors are rebuilt with no problem for $300 USD.

Much better to buy an e-bike with a motor that doesn't have to be rebuilt after only a few hundred miles.

Thats how these Kalkhoffs used to be when they fitted Panasonic motors for the early years from 2009. The switch to the German Daum motors, (renamed Impulse), was a disastrous mistake.
.

 

[USAebike]

Much better to buy an e-bike with a motor that doesn't have to be rebuilt after only a few hundred miles.

Thats how these Kalkhoffs used to be when they fitted Panasonic motors for the early years from 2009. The switch to the German Daum motors, (renamed Impulse), was a disastrous mistake.
.

Manny people have Daum motors with thousands of mile on the original motors. The rumors spread on these forums are wrong. And yes, Bosch motors also break. Ask me how I know.

 

[flecc]

Manny people have Daum motors with thousands of mile on the original motors. The rumors spread on these forums are wrong. And yes, Bosch motors also break. Ask me how I know.

I agree Bosch motors also break, and have done since their earliest days.

But don't try to kid us that the Daum Impulse motors are reliable, the Impulse 2 in particular is very far from that, most failing well within 2000 miles. How else do you account for bikes receiving up to FIVE replacement motors under warranty, once it had been agreed that the warranty continued for those that broke within two years.
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