Regarding charging to 80% vs 100%, here is the best data that I have.

I bought a used second battery some time ago. The power connector had overheated and melted. The owner couldn't repair it; so I bought it as a spare and replaced the bad connector. The owner said she had put about 4000 miles on it, which I estimate to be no more than 150 cycles, maybe less. I just tested that battery today.

In the chart, blue is my original battery new, and green is that battery after over 300 charge cycles to 80%. Red is the second-hand battery that was charged maybe 100 - 150 cycles to 100%. Remember we are talking about complete charge cycles.

Most consider the battery to be discharged at 42V, where power drops off. We can see that at 42V the 100% charged battery has lost about 2 miles in distance capability, or about 10%. Not huge, but measurable. It will likely degrade more with additional charge cycles to 100%. I would guess at 300 cycles the loss might be about 20%.

Remember this test is at full throttle with a maximum distance of 20 miles. If you use PAS and pedal 40 miles on a charge, you would likely lose 4 miles.

It is noteworthy that power is not reduced, only capacity or distance. If you don't take long rides, you would never notice the difference.

I tested the Standard Battery on my Rover 5 when it was new, and now again after 5+ years and about 5000 miles on this battery. (I have 8700 miles on the bike, but have two batteries which I occasionally swap.) The battery has not noticeably degraded.

The test consists of my riding the bike throttle only fully open on level roads until it virtually quits. I stop every two miles and measure the battery voltage after 60 seconds. The battery is still performing like new, except for the last few miles.

I ride 12 miles most every day, and charge to 80% after every ride. The bike lives in my garage in Florida, so it is subject to 80+ degrees (often 90+) nearly all year. I have a meter on my charger that shows that the charger adds about 110 Ah on a charge, which is about 1/6th capacity. So I'm doing the equivalent of one full charge every 6 days. That works out to about 335 full charge cycles. Rad advertised 800 cycles on the battery when I bought the bike; the cell manufacturers say 500 cycles.

It's extremely unlikely that a fuse blew on its own. I understand there is a "ship" mode for these batteries - maybe check that?

Quote from: sunnymike on September 18, 2024, 11:18:51 AMThanks for the reply,

The batteries shutdown without any load on the output of the converter.

I have leads from the neg. and pos output on each battery. I then connect both neg leads to the common lug on the convertor and both pos leads to the pos lug on the converter. It doesn't matter if I connect one or both batteries, they shut down in both cases.

I am a little surprised that the 3 little connectors go nowhere. There are 3 little pins in those spots on the connector. I was betting they were for that 3 button switch on the handlebar that turns the power on, selects the PAS setting and other switching functions. Oh, well. That's why I am asking you for help because guessing just gets me into a lot of trouble.

You may be getting a current spike into the converter even if the converter is not connected to a load. Hard to determine without an oscilloscope.

Connecting batteries in parallel as you described is problematic if the batteries are not at the same charge voltage. The batteries can be charged through the load connection, as happens with a regen bike. If the voltages are different, you're going to get current flow from one battery to the next which, depending on the difference, could be a sizable current. You should be using a Datex2 or similar device.

Do you have any specs on the current draw of the converter and of the trolling motor? Or at least pounds of thrust specs? You may be asking too much of the bike batteries. With inefficiency of the converter I suspect that you're not going to get a lot of run time with the bike batteries. I need some info on the converter and trolling motor.

I would guess that the BMS in the older battery is shutting the battery down because of excess current draw or unbalanced cells. Try test connecting a lesser load, such as several automotive batteries in series.

The three smaller pins are not connected to anything.

How are you connecting these batteries in parallel? This is potentially problematic.

Quote from: Ledbetter on August 22, 2024, 01:01:10 PMI'm looking forward to joining "the dark side," as I've always thought of e-biking as cheating. Can't wait for it to get here.

I checked the rule book - nope, not cheating.

This one matches Rad specs.  48V (54.6V peak or "float" voltage) 2A 13S (13 cells in series = nominal 48V):

https://amzn.to/4eTozt6

That would work; you need a 48V power supply.

Quote from: John Rose on February 28, 2024, 04:09:05 PM

Quote from: DickB on February 28, 2024, 05:35:34 AM
...  You're correct in that the charger does not balance cells, but the BMS balances if needed when at the float voltage and charge current is small. If you shut the charger off early rather than lower the float voltage, current remains high and balancing does not take place.

That sounds very likely.

Did you find that graph somewhere, or is it from your own set of measurements?

My measurement.

I recently had this same failure on my Rover 5. Inside my controller are two auxiliary circuit boards in black shrink wrap. One is circled in green, the other is below it and to the upper left. One board is for the headlight/tail light and one for the brake light. I replaced it with a used board from a Facebook group member's controller, which he kindly removed from a non-working controller. My tail light was also dead; I don't know if it failed and took out the auxiliary board or vice versa. I replaced the tail light with an aftermarket one.

Chargers are Constant Current / Constant Voltage, meaning that they limit current at the start of the charge (while voltage increases), then limit the voltage (while current decreases) to what is called the float voltage. If you set the Luna charger to 80% it simply lowers the final float voltage.  You're correct in that the charger does not balance cells, but the BMS balances if needed when at the float voltage and charge current is small. If you shut the charger off early rather than lower the float voltage, current remains high and balancing does not take place.

I posted that photo on Facebook. Someone responded that the labels are just to satisfy local requirements, and in fact the controllers are capable of 25A, and that an EggRider display can "unlock" more power.

I got a replacement board from John Fitzgerald on Facebook. Turns out the tail lamp was bad as well. I don't know if one took out the other, or what happened. But I installed the replacement board and new tail lamp and all is well.

The controllers are different with different part numbers. Someone posted (on Facebook?) a comparison photo of USA and Canadian labels. The difference in power output is in the controller. I don't see why there would be different part numbers for the display.

I'm looking for a non-working Rad controller for parts.

I have a Rad Rover 5. The controller has a main circuit board and two auxiliary boards, one for the brake light and one for the head/tail lights. I'm looking for one auxiliary board - it doesn't matter which one as they are identical. The head/tail light quit working on my bike; the board is bad.  Even if your controller is bad, it is likely that the auxiliary boards may be OK.

I suspect the same boards may be found in other Rad controllers, so if you think you have one other than a Rover 5 it may still be applicable.

The auxiliary boards are enclosed in shrink wrap (see photo).

Please contact me if you think you may be able to help.