Help with LifePo4 on R100/7

[d90]

Hi guys

I don't speak German, so I hope you can bear with me, that I'm asking in english

I have had some trouble with my Lifepo4 battery on my old R100 / 7 (1978) which I have turned into a cafe racer.

I have kept the stock wiring, points and charging system. (Everything refurbished)

For new parts I have installed LED's in the flashers, taillight and DAYTONA speedometer (LED also). The headlight is running a 30w / 30w bulb (which isn't much more than an LED bulb). Also installed an adjustable voltage regulator set to around 14.2v.

I have also installed a valeo starter, to save on draw amperage when starting.

I have bought this battery:

https://www.caferacerwebshop.com/en/jmt-hjtx20ch-fp-bmw-r-serie-lithium-accu.html

Specifications:

Voltage: 12V
Capacity: 6 Ah (10 Std)
Capacity: 72 Wh
Type: Lithium
Maintenance-free
Manufacturer claimed CCA: 360 A
SAE as measured by JMP battery tester: 545 A
DIN as measured by JMP battery tester: 510 A
EN as measured by JMP battery tester: 300 A

The battery started the bike fine at first, but now it cannot crank the engine. It is fully charged by (13.4) with an LifePo4 charger.

It seems like it cannot draw amp's anymore, as the starter will not crank

When using an external power starter the engine cranks again.

Would you happen to know, what has gone wrong? And is there a way to improve my setup?

Best,

 

[hg_filder]

Sorry about my eglish, but i try to answer.

First: Do you use a 47 Ohm resistant for the charging-system? Background: To start der generator, the systems need an external current, which ist comming from the 3 Watt indicator. If you are using only an LED as an charging-indicator, the generator does not work. Test: Start the engine and test the voltage an the batterie: higer than 13,7 Volt -> Charging-System is running.

I can't see, except the point above, any mistake. If you have another bike, try to start this with this battery. If ist is also not cranking, the battery ist possibly dead.

Hans

 

[Manitoba]

Hi nameless guy,

as the starter works by using an external battery and cranks the motor, the Valeo starter obviously do its job.

If I understand well the issue, the battery has 13.4V without any workload coming from the Valeo starter when you try to start the engine .

Please check the voltage of the the batterie when you try to start the engine by using the Lifepo4 battery. What voltage to you have during cranking the engine?

I suppose it will be significantly below 12V. if it is so, I suppose your Lifepo4 battery went over the rainbowbridge and you have to say "see you next life".

 

[d90]

Sorry about my eglish, but i try to answer.

First: Do you use a 47 Ohm resistant for the charging-system? Background: To start der generator, the systems need an external current, which ist comming from the 3 Watt indicator. If you are using only an LED as an charging-indicator, the generator does not work. Test: Start the engine and test the voltage an the batterie: higer than 13,7 Volt -> Charging-System is running.

I can't see, except the point above, any mistake. If you have another bike, try to start this with this battery. If ist is also not cranking, the battery ist possibly dead.

Hans

Hi Hans

Thanks for the advice.

Yes I have wired in this resistor:

https://www.kickstartershop.de/en/resistor-loading-light-bmw-2-valves

[FONT=pt_sansbold]Electrical values
-Nominal load: 5.0 W[/FONT]
-Resistance: 120 ohm


Here's pics of the resistor wired in from coil to blue wire on the voltage regulator

and a pic of the other side, for good measure.

I have only taken the bike for a short ride. It has mostly been sitting on battery tender charging, with a LifePo4 charger.

So I haven't had the chance to test the charging system at all, since it has barely been activated with the new battery.

Best

 

[d90]

Hi nameless guy,

as the starter works by using an external battery and cranks the motor, the Valeo starter obviously do its job.

If I understand well the issue, the battery has 13.4V without any workload coming from the Valeo starter when you try to start the engine .

Please check the voltage of the the batterie when you try to start the engine by using the Lifepo4 battery. What voltage to you have during cranking the engine?

I suppose it will be significantly below 12V. if it is so, I suppose your Lifepo4 battery went over the rainbowbridge and you have to say "see you next life".

Hi Manitoba

I will test it, and report back. Sadly I think you might be right that the battery is gone If I could just figure out, what causes this. As the battery has never dipped below 10V, so nowhere near a deep discharge!

Best,

 

[ullil]

Hello,
What temperature do you have in your garage?
At temperatures below 5 °C, my battery is also a bit tired
Wait 1 minute after the first start attempt.

 

[d90]

Hello,
What temperature do you have in your garage?
At temperatures below 5 °C, my battery is also a bit tired
Wait 1 minute after the first start attempt.

Hi ullil

It's in a heated garage, constant 15 degrees C

I let the lights on for 1 minut and heated the garage to 20c but sadly it didn't help.

Again it seems the draw amperage is shot for some reason I cannot figure out..