10-14-2025, 09:35 PM
My 28$ 1800 watt/ 40 amp voltage booster bought on Ebay, was shipped 'economy shipping' , no tracking, expected delivery " by October 30th', arrived today, the 14th. Was Not USPS. I got a text saying my package was delivered while at the park with Fiona, and assumed it was a spam text, but Alas, it was at my front door well before USPS ever arrives.
I have made some 10 AWG ring terminal to 45 amp APP cables and am testing it now, but only at low amps as my Esk8 batteries are quite near full.
So far so good, and it seems to be quite efficient, wasting only 1.2 watts boosting 11.98v to 28.34v at ~ 20 watts input.
it is a pretty big bulky booster in comparison to blue, red or white boosters, but bench charging, this is no concern/ I should be able to charge at 420 watts, 42V 10 amps output, from 12v nominal without issue, where my other boosters seem limited to the 150 to 170 watt maximum.
It is a bit bigger than I'd want for stuffing in the chariot's fanny pack, just to be able to charge from my 3s4p at more than 170 watts.
I'll be testing all my boosters using same wattmeters on input and output, from my GC-2 AGM's, feeding my Esk8 battery, but this one is obviously the most capable, and if physical size is not a factor, I'd recommend just getting this one rather than bothering with the blue red or White boosters.
I got to say the blue booster for under 150 watts will continue to be my favorite. mainly as it has the LED which can be dialed via potentiometer to turn from red to green when amps taper to below a chosen level. i can walk into the garage and see a green light and know the battery is accepting somewhere less than 0.3 amps. the red booster has no lights. The white booster has a red light but stays red whether it is uoutputtng 170 watts or 1 watt, same with this 1800 watter.
Right now, I am charging my premade junky 7s1P battery from my 3S4P Samsung 50E at ~ 30 watts. The Samsung's 3 parallel packs are staying within 0.004 volts under any load from 2.5 to 15 amps, which I find impressive, but perhaps is not.
The Big red booster is staying cool at this level. It has a fan attached to its heatsink, but it must be temperature controlled as it has not yet turned on.
The proprietor of diy500amp dot com says he has three of these big red boosters, and says they are good. He has modified one of them with better rated Mosfets diodes and capacitors.
Mine came with the output adjusted to 58 volts, and when dialing down the current potentiometer, 0.68 amps seems to be the minimum throttling it is capable of, where my smaller boosters will throttle ma amperage to much lower levels. This can be good if trying to allow the BMS to balance an old pack which falls out of balance easily.
Poorly made battery packs of dubious consistency( or well aged) cells seem to need to rely on the BMS to top balance, but these also only can bleed off voltage with something like 0.02 to 0.035 amps of current, maximum, so if badly out of balance a faster charger will basically be too fast to allow the BMS to fully top balance a pack.
My Dumb Daly BMS's start balancing cells when a p group reaches 4.18, so i will set the charge voltage at 41.8v( 10S), and will dial amperage down to the Sub 10 watt level. I can then bump max voltage ( unloaded) to 41.85, .90, .95 at these low wattages and in theory they wshold have more than enough time to perfectly top balance.
But really this is not vey important. It is said unless parallel groups start varying more than 30 MV, then performance is not affected.
I have not bothered testing my BAK 45D 10s2P balance in a long while, and feel like I need to scold myself for even charging it to 42 volts as I rarely have issues with range, and charging to 4.2 volts is unnecessary and will negatively affect cycle life.
but compared to Lead Acid batteries and their shit poor service life unless coddled and quickly and fully recharged every cycle......
1200 Cycles should be easy to accumulate when cycling from 4.1 to 3.2 volts with Liion cells.
Manufacturers wll spec numbers like 400 Cycles at 0.5C charge, 2C discharge and 80% capacity remaining, cycling from 4.2 to 2.5v, and these are just guaranteed minimums.
I am rather amazed 20 21700 cells made into a 36v nominal battery under my feet can propel me and Fiona to 25mph and give me 10 miles of range and do this thousands of times before it might only be 8 miles of range.
I have made some 10 AWG ring terminal to 45 amp APP cables and am testing it now, but only at low amps as my Esk8 batteries are quite near full.
So far so good, and it seems to be quite efficient, wasting only 1.2 watts boosting 11.98v to 28.34v at ~ 20 watts input.
it is a pretty big bulky booster in comparison to blue, red or white boosters, but bench charging, this is no concern/ I should be able to charge at 420 watts, 42V 10 amps output, from 12v nominal without issue, where my other boosters seem limited to the 150 to 170 watt maximum.
It is a bit bigger than I'd want for stuffing in the chariot's fanny pack, just to be able to charge from my 3s4p at more than 170 watts.
I'll be testing all my boosters using same wattmeters on input and output, from my GC-2 AGM's, feeding my Esk8 battery, but this one is obviously the most capable, and if physical size is not a factor, I'd recommend just getting this one rather than bothering with the blue red or White boosters.
I got to say the blue booster for under 150 watts will continue to be my favorite. mainly as it has the LED which can be dialed via potentiometer to turn from red to green when amps taper to below a chosen level. i can walk into the garage and see a green light and know the battery is accepting somewhere less than 0.3 amps. the red booster has no lights. The white booster has a red light but stays red whether it is uoutputtng 170 watts or 1 watt, same with this 1800 watter.
Right now, I am charging my premade junky 7s1P battery from my 3S4P Samsung 50E at ~ 30 watts. The Samsung's 3 parallel packs are staying within 0.004 volts under any load from 2.5 to 15 amps, which I find impressive, but perhaps is not.
The Big red booster is staying cool at this level. It has a fan attached to its heatsink, but it must be temperature controlled as it has not yet turned on.
The proprietor of diy500amp dot com says he has three of these big red boosters, and says they are good. He has modified one of them with better rated Mosfets diodes and capacitors.
Mine came with the output adjusted to 58 volts, and when dialing down the current potentiometer, 0.68 amps seems to be the minimum throttling it is capable of, where my smaller boosters will throttle ma amperage to much lower levels. This can be good if trying to allow the BMS to balance an old pack which falls out of balance easily.
Poorly made battery packs of dubious consistency( or well aged) cells seem to need to rely on the BMS to top balance, but these also only can bleed off voltage with something like 0.02 to 0.035 amps of current, maximum, so if badly out of balance a faster charger will basically be too fast to allow the BMS to fully top balance a pack.
My Dumb Daly BMS's start balancing cells when a p group reaches 4.18, so i will set the charge voltage at 41.8v( 10S), and will dial amperage down to the Sub 10 watt level. I can then bump max voltage ( unloaded) to 41.85, .90, .95 at these low wattages and in theory they wshold have more than enough time to perfectly top balance.
But really this is not vey important. It is said unless parallel groups start varying more than 30 MV, then performance is not affected.
I have not bothered testing my BAK 45D 10s2P balance in a long while, and feel like I need to scold myself for even charging it to 42 volts as I rarely have issues with range, and charging to 4.2 volts is unnecessary and will negatively affect cycle life.
but compared to Lead Acid batteries and their shit poor service life unless coddled and quickly and fully recharged every cycle......
1200 Cycles should be easy to accumulate when cycling from 4.1 to 3.2 volts with Liion cells.
Manufacturers wll spec numbers like 400 Cycles at 0.5C charge, 2C discharge and 80% capacity remaining, cycling from 4.2 to 2.5v, and these are just guaranteed minimums.
I am rather amazed 20 21700 cells made into a 36v nominal battery under my feet can propel me and Fiona to 25mph and give me 10 miles of range and do this thousands of times before it might only be 8 miles of range.
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