10-15-2025, 08:16 PM
Glad you caught the Fedex truck.
Did you battery assembler advertise what cells they use by any chance? Could they be 21700's? They are so much more economical, but if the battery enclosure was designed around 18650's then they cant easily swap to the more economical cell with greater capacity.
I attached my old Nitecore HC50 to the chariot. it has some red leds, and a flashing mode. I forget to turn it on sometimes in the daytime, but at night there is a pretty healthy red glow behind the chariot. I did the ride until after dark tonight to Beeping ESC mode( low battery) with both Armytek and Sofirn right angle headlights. it would be great if they could maintain higher output, but they both thermally throttle. The sofirn will go back to turbo with a double click and the armytek will go back towards turbo2, with a single click, and when both are at or near turbo, light levels are impressive, but when they throttle, it is a bit disappointing. Certainly enough to see, the road surface, but more would be better.
I charged the new Samsung 6S1P 50E to 25.2 volts until amps tapered to less than 0.1, and put it on Big red booster, and Dialed up 9.8 amps input to booster.
The input amps keep climbing as it is a constant current output, and I kept dialing it down, ever minute or so.
The big red booster's fan came on for the first time after a while. it is pretty high rpm, I'd guess 2500. I will test this with optical tach at a later date.
basically I was starting out at about 215 watts charging my Esk8 battery and by the time the Samsung 6s1p had fallen to about 20.5 volts, My IR gun had found a 58.8C temperature on the end of one cell, and I quit the test, and foolishly did not record the Amp hours delivered.
The Continuous Discharge Rate of a cell, is determined using a single cell in free air about 25C ambient. The CDR so the maximum amperage a cell can be discharged at without overheating before it reaches it's 2.5 minimum voltage spec.
The Samsung 50E, and most energy cells are rated to only 60C. Most power cells are 75 to 80C.
My 58.8C temperature reading on the end of a cell was taken through one layer of Tesa tape, and one layer of Kapton tape, and one layer of clear PVC heatshrink, So the cell could have exceeded 60C.
My battery pack started around 25C from being inside the house, but the garage is 32C.
So I basically pushed the battery a bit too hard, and if I were to simply plug it in, dial up 10 amps on the input, it likely would have greatly exceeded 9.8 amps max, and 60C before the BMS cut power. The BMS has a little spot on PCB for an NTC temp sensor, which would be good to have if intending to push this pack this hard on the regular,
Just before removing it from booster I saw about 175 watts, which is still a very respectable charge rate but I started about 215.
I think this 6S1P battery, and the white booster, could be set to 160 watts or so and not overheat either the battery or the Booster, and drain from 4.2 to 2.8 volts per cell without overheating. This is probably the most effective compact portable charger method I have. I could fit the battery in one cargo short pocket and the booster in the other thigh pocket, and charge at upto 160 watts, and likely return somewhere close to 95 watt hours into my 324Wh BAK45D main battery.
Not too shabby. That should be good for at least 3 additional miles towing Fiona at near 20MPH.
But this 6s1P was made for the soldering iron which can only draw 82 watts, and only briefly. This was just a test. If I were making a battery for portable charging I would probably make a 9s1P of a higher CDR cell, but if going there just make another 10S1p battery and plug it into the charge port as we roll..
of course it would be better to not have to stop just to charge at all, but We do stop at parks and lookouts anyway.
Now my 3s4P 50E with 12 cells, has double the watt hours, and the lower input voltage makes the booster work harder, but the battery should be able to handle 35 amps continuous output without overheating. The whitebooster is then the limiting factor with its 15 amp fuse on input and 10 amp input rating.
The Big red booster is just too big for being a good portable charger, even though is seems to be rated for 40 amps input.
One interesting with Big Red, is it has a temperature sensor in contact with the heatsink, and when the fan first fires up, it only runs for a second or two, then shuts off, then comes back on, and basically cycles more off than on, but then becomes similar in both on and off times.
I put a blob of thermal grease on the sensor so it could better sense the heatsink, but it still cycled on and off, and the heatsink did not seem all that warm to the touch. Bare aluminum so hard to get a good reading with IR temp gun.
I am charging my 3s4p 50E back to full from a 5 amp bucker, and will go charge the esk8 battery from Big red booster, see how fast I can charge esk8 battery from it, upto 10 amps output anyway.
Did you battery assembler advertise what cells they use by any chance? Could they be 21700's? They are so much more economical, but if the battery enclosure was designed around 18650's then they cant easily swap to the more economical cell with greater capacity.
I attached my old Nitecore HC50 to the chariot. it has some red leds, and a flashing mode. I forget to turn it on sometimes in the daytime, but at night there is a pretty healthy red glow behind the chariot. I did the ride until after dark tonight to Beeping ESC mode( low battery) with both Armytek and Sofirn right angle headlights. it would be great if they could maintain higher output, but they both thermally throttle. The sofirn will go back to turbo with a double click and the armytek will go back towards turbo2, with a single click, and when both are at or near turbo, light levels are impressive, but when they throttle, it is a bit disappointing. Certainly enough to see, the road surface, but more would be better.
I charged the new Samsung 6S1P 50E to 25.2 volts until amps tapered to less than 0.1, and put it on Big red booster, and Dialed up 9.8 amps input to booster.
The input amps keep climbing as it is a constant current output, and I kept dialing it down, ever minute or so.
The big red booster's fan came on for the first time after a while. it is pretty high rpm, I'd guess 2500. I will test this with optical tach at a later date.
basically I was starting out at about 215 watts charging my Esk8 battery and by the time the Samsung 6s1p had fallen to about 20.5 volts, My IR gun had found a 58.8C temperature on the end of one cell, and I quit the test, and foolishly did not record the Amp hours delivered.
The Continuous Discharge Rate of a cell, is determined using a single cell in free air about 25C ambient. The CDR so the maximum amperage a cell can be discharged at without overheating before it reaches it's 2.5 minimum voltage spec.
The Samsung 50E, and most energy cells are rated to only 60C. Most power cells are 75 to 80C.
My 58.8C temperature reading on the end of a cell was taken through one layer of Tesa tape, and one layer of Kapton tape, and one layer of clear PVC heatshrink, So the cell could have exceeded 60C.
My battery pack started around 25C from being inside the house, but the garage is 32C.
So I basically pushed the battery a bit too hard, and if I were to simply plug it in, dial up 10 amps on the input, it likely would have greatly exceeded 9.8 amps max, and 60C before the BMS cut power. The BMS has a little spot on PCB for an NTC temp sensor, which would be good to have if intending to push this pack this hard on the regular,
Just before removing it from booster I saw about 175 watts, which is still a very respectable charge rate but I started about 215.
I think this 6S1P battery, and the white booster, could be set to 160 watts or so and not overheat either the battery or the Booster, and drain from 4.2 to 2.8 volts per cell without overheating. This is probably the most effective compact portable charger method I have. I could fit the battery in one cargo short pocket and the booster in the other thigh pocket, and charge at upto 160 watts, and likely return somewhere close to 95 watt hours into my 324Wh BAK45D main battery.
Not too shabby. That should be good for at least 3 additional miles towing Fiona at near 20MPH.
But this 6s1P was made for the soldering iron which can only draw 82 watts, and only briefly. This was just a test. If I were making a battery for portable charging I would probably make a 9s1P of a higher CDR cell, but if going there just make another 10S1p battery and plug it into the charge port as we roll..
of course it would be better to not have to stop just to charge at all, but We do stop at parks and lookouts anyway.
Now my 3s4P 50E with 12 cells, has double the watt hours, and the lower input voltage makes the booster work harder, but the battery should be able to handle 35 amps continuous output without overheating. The whitebooster is then the limiting factor with its 15 amp fuse on input and 10 amp input rating.
The Big red booster is just too big for being a good portable charger, even though is seems to be rated for 40 amps input.
One interesting with Big Red, is it has a temperature sensor in contact with the heatsink, and when the fan first fires up, it only runs for a second or two, then shuts off, then comes back on, and basically cycles more off than on, but then becomes similar in both on and off times.
I put a blob of thermal grease on the sensor so it could better sense the heatsink, but it still cycled on and off, and the heatsink did not seem all that warm to the touch. Bare aluminum so hard to get a good reading with IR temp gun.
I am charging my 3s4p 50E back to full from a 5 amp bucker, and will go charge the esk8 battery from Big red booster, see how fast I can charge esk8 battery from it, upto 10 amps output anyway.
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