Well, technically THIS is the OEM, not Ohrija. Ohrija is just one of many companies selling this OEM’s products. But there’s nothing wrong with ordering from them, as you generally cant buy directly from an OEM unless you’re in china and/or buying hundreds of units.
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I’m on a hunt for the smallest fanless 84v (full-charge) charger/power-supply
I see some possibilities above hoping they’re sold locally
I just got this. Not that small and has a fan but has to be the cheapest
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A one and only:
Quiet and small and 84v full charge
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New DC-DC charger I built. I prefer DC-DC because they are cheap and I can charge to multiple voltages on one power supply. Mostly I charge 15S and 20S.
1500W DC-DC Boost Converter
Multimeter Display
Power supply I use
I used left over material for the 3d printed enclosure so it looks a bit janky. Efficiency is good. It gets about 97% if the voltages are within 10-20V and gets down to 90% at more extreme boosts.
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So, I too fastISH charge when I use. What IIIII need to know is, when you fastish charge before use, how long to let cool before turning on? I have been told NOT to run right off charger. And answer that for 100 and 80 percent charge.
Use to be, pulse repair mode, was said to be ONLY for NON agm batts. NOW, they build the Chinese chargers with repair mode that they say is good also for agm batts.
In the rc plane world they’ll heat up a battery before use so more easily discharge high amps.
This is an awesome build. Thanks for sharing.
All my Esk8 chargers are CC/CV Voltage boosters, usually from 12v nominal, but 18v and 25.2v nominal are also now in the mix, boosting to 10S voltages.
Have you been able to confirm that the Drok voltmeter/Ammeter display is relatively accurate and consistently so? I’ve had very inconsistent accuracy with these, in both, and kind of just shoulder shrugged and remember the Asterix factored their use.
Is the Fan Noisy? I had one of these 1500 watt V boostersthat I fried when powering 24v hedge clippers from a 12v battery, and regret not salvaging the fan or heatsink before abandonment.
These style of fan’s blades often stall, when there is resistance to flow close to the intake side of the fan. Moving that resistance just 5mm away can make a huge difference in both airflow, and the noise the fan makes. I highly Recommend experimenting.
Getting a 50mm ( IIRC the 12v fan was 50mm, could be wrong) finger grill and mounting it on the outside of the case could make vast improvements in both airflow and noise, as would a puller fan on the other side.
The fan provided with my booster was sleeve bearing, with poor CFM and Static pressure specs compared to a Noctua or Delta Or Nidec fan of same dimensions and Amp draw.
if the fan fails the Booster could smoke itself so I feel that the best way to prevent magic smoke is with a quality dual ball bearing or Maglev fan that can scavenge all the air it needs without excessive restriction behind or in front of the blades. But flow restriction in front of blades is far better than restriction behind.
I’m charging at 3 amp per cell on p42a and p50b, which I think can handle 4 amps, so it does not really get that hot. I think I usually see 35 degrees C at the most so I don’t even consider cooling before riding.
It’s quiet. Much more quiet than the power supply. I’m running about 800W and the fan is only running intermittently. I think the heat sink is plenty large for the heat generation so it should be good for over 1000W but the documentation even says if you plan to run 1500W you should have some additional cooling. That’s a good thought about fan reliability. I might swap it out.
I had a similar looking power supply before I got my Meanwell RSP-500-15. Its provided exhaust oriented fan was pretty loud a with a lot of restriction close to fan blades.
I modified the Lid to put the fan on the outside of the case, and the flow and noise was greatly improved.
That particular power supply had no current limiting, and was rated at 30 amps. if the target voltage was set high enough it would exceed 36 amps and start making a high pitched whine and clicking noise. I had modified the voltage potentiometer to 10 turn fingertwist, and had to manually prevent more than 36 amms from flowing, and keep bumping it up as the lead acid battery charged.
One day I got sick of the manual voltage twiddling and decided to just set it to 14.6v on a well depleted battery and let it rip, whining and buzzing.
magic smoke in 16 minutes IIRC.
I then ordered the meanwell, and added 2 Noctua fans to the steel lid. One 60mm blowing in, one 80mm sucking air out. These two keep the Meanwell’s insanely loud 40mm fan from kicking on except in hot ambient temps and 20+ minutes of 40 amps output.
I first modded the meanwell 11 years ago, and it has been plugged in continuously for the last 2.5 years producing 13.6v, but the full voltage range is 13.12 to 19.23, and rated for 500 watts it will do 600 all day long if one asks it to.
I have had to open it up and clean out the dust.
I love noctua fans for slow speed quiet efficiacy, but I started liking Delta fans more, and getting super high RPM 12 and 24v models and speed controlling them with a XL4005 voltage bucker.
In the case of the 24V Delta fan a buck boost as the voltage range of the fan is ~7 to 29.5v
For longevity, peel up the sticker where the power wires enter the fan hub, and cover their solder joints with a proper product for encapsulating them. otherwise the + and - will grow white and green corrosion and at best the wire disconnects from circuit board, at worst the corrosion seeps up the traces and fan goes Bye bye.