Originally Posted by GRNordstrom
I looked up Meanwell and got a group of what I think are fixed power supplies but no adjustable ones. The descriptions didn't mention adjustability.. What am I missing?
These power supplies have small voltage adjusting potentiometers right next to the 120vac input and DC output terminals.
These are only rated for 100 cycles, they are more meant to be set to a certain voltage with a jewelers screwdriver, and forgotten.
I removed this potentiometer(1K ohm) and added a 10 turn 1K ohm potentiometer making voltage adjustments to 0.01v simple.
I doubt these are acceptable as full time marine
chargers. Mine(rsp-500-15) is used on a land based battery
bank, and often maxed out at 40 amps. I have added extra ventilation( 12v muffin/ computer fans) and some large finned aluminum
heatsinks adjacent to the transistors which use the casing as a heatsink, as it does get hot at max output. Also the provided 40MM fan is quite loud and would cycle on and off at only 6 amps output. My quieter 12v fans and heatsinking keep this fan off upto 30 amps or so, depending on ambient temperature
Do note that only a Few Meanwell power supplies have constant current
limiting on Overload, and the RSP series is one of them.
limiting protection on overload is pretty much a requirement for battery charging
. Without this feature they either shut off until overload( depleted battery) is removed, or cycle on and off rapidly, or they roll back current
With these power supplies one must provide their own AC cord, as well as the DC output cables
I have used my Meanwell in parallel with other plug
sources to increase amperage in constant current phase, but I usually need to bump up voltage to keep it at max output, and I need to be there to lower voltage once absorption voltage is neared.
There is a HEP series of meanwell power supplies that have both current and voltage adjustment as well as constant current limiting on overload:
If used on an Aged Lifeline bank that is already as charged as it can get at 14.x volts, then these batteries should not be able to max out such a power supply trying to bring them upto 15.5 volts from that point, but a Depleted battery is an overload making the constant current on overload necessary for use as a regular charger
I have added a RC wattmeter, whose leads I upgraded to 8awg, on the output of my Meanwell:
With 8awg it only gets warm pasing 40 amps, but it was hot with the provided 12awg aluminum
leads at 30 amps continuous.
Generally one needs a voltmeter on the battery and one on the output, and set the desired end voltage when unloaded, then hook up the battery bank.
These meanwell power supplies are surprisingly small.
There is another brand called the Megawatt that appear to be made well too.
Before I got the Meanwell, I experimented with a 23$ 30 amp power supply(max 15.3v) which appears to be a megawatt clone. This had no overvoltage/overtemperature or overcurrent protections. It would output 36 amps, but if the voltage was turned a bit higher it would go a bit over 36 amps and start clicking.
Tired of having to micromanage the Voltage potentiometer to keep it just under 36 amps, I just set it to 14.7v and hooked up a depleted battery. 17 minutes later it released the magic blue smoke and I had an excuse to buy the MeanWell.
If one wants to go the adjustable voltage power supply route
as more than an equalizer/conditioner applied to an already 'full' battery bank, well I am not sure how safe they are for a marine
application with stray voltage, and of course they are not ruggedized for marine exposure.
Often changing the voltage will wear out the original micro potentiometer, and replacing this with wires to lead to a 10 turn pot rated for thousands of cycles, requires complete disassembly and some soldering skills. One also needs to have thermal grease to reapply as many transistors are held to the casing which is used as a heatsink.
So it is not really plug
and play when used as a bulk charger
, but for an equalizer/conditioner, one can set it to 15.5v once, and attach it to the bank needing conditioning, and just follow Lifeline's procedure from there. It should not be maxed out where overheating
or overcurrent becomes an issue, and the original mini potentiometer need not be fiddled with.