SternWake
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Mobilesport said:For me the colder it is outside the more I have to charge my batteries because my furnace runs the batteries down overnight , so hopefully this means I'm not as hard on the charger , that fan and heat sink you have there is a good idea , I'm thinking of doing something similar for the summer heat , I'll probably use a small box fan that runs off of 110v to cool the meanwell.
Thanks for all the info on the Meanwell
I see the rsp-750-15 only has the large single DC outputs. I wound up hooking my extra Noctua fans to the 12vDC outputs as there are 3 sets on the rsp-500-15.
Ventilation through and around the case are important. While the transistors inside either have their own finned heatsinks or use the casing as a heatsink, it is the toroids which likely generate the most heat, and these are the round hollow magnets with copper coiled around them.
Part of my reasons for the extra fans was to keep the very loud 40MM meanwell provided fan from coming on as on mine I will set it to float voltage and power all loads overnight and do not want to have to listen to that loud fan cycling on and off.
Without the extra fans it would cycle on and off at just 6 amps output. Now it wont come on until 34 or more amps output.
But ambient temperatures play a pretty big part in this number. If you were not required to send the failed powermax back, they have a large finned heatsink inside you could remove and attach to the casing with some thermal epoxy.
Mine had some depressions on the side of the case and I had to grind and file my heatsinks down to fit tightly inside these, and also had to drill holes around the screws which hold the transistors tightly to the casing so I can get it apart in the future, if I have to.
I put a thermocouple on the internal heatsink on mine opposite a Meanwell temperature sensor( there are 2). My data reveals the internal fan comes on when this internal heatsink hits 103.6f and fan does not shut off until it falls to 98.6f.
The Highest I have seen is 114f. If I put my hand over the 60Mm noctua fan, which is directly over the internal heatsink, the temperature skyrockets surprisingly fast.
I sometimes think about adding even more airflow. Where my MW resides, on my cabinet door, I usually have cabinet door open when asking for its full output and can plug in a USB fan right above it to aim at it. This does not much affect the my temp readings on internal heatsink. But if I take one of my regular internal comfort fans, a 92MM vantec tornado and aim it's full flow at the opening where the wires exit the MW, I can get temperature to plummet.
Overkill, but I like to experiment and observe results.
I really love this charging source. I got so sick of the Schumacher going batcrap crazy and choosing damaging voltages or reverting to float voltage way too soon and requiring me tricking it by artificially loading batteries to reduce voltage to below 12.6v and restarting it. The Schumacher automatic charger required babysitting and manipulation into doing its job.
I was looking at all the converter offerings and all of them appeared to be a compromise and less than ideal.
With this MeanWell power supply, i plug into 115vac, adjust voltage to 14.91( accounting for voltage drop on the DC output wires) to achieve 14.5 to 14.7v or so, then plug in the anderson 45 amp powerpole connector and boom, 40 amps. then let it go. In 20 to 40 minutes my depleted battery is up at 14.46v or so and amps start tapering, and I back off the voltage a smidge to make sure it does not exceed 14.7v at battery terminals as the lower amperage will cause less voltage drop.
Once amps into the battery fall to 0.4 or less, I lower voltage to 13.6v and keep it there until I Unplug. Even if the sun rises and the solar can take over, I can leave it plugged in, but sometimes hear it click on or off depending on the voltage setpoints, which is higher float, the solar or the meanwell. Usually I disconnect when the sun is shining and the battery is full, but sometimes cannot be bothered, especially if I have no plans on driving anywhere.
I've definitely gotten thousands of hours on this unit, much of it providing current only in the 1 to 6 amp range, powering DC loads while holding the battery at float voltage. My additional fans run continuously whenever the unit is plugged into DC, even if disconnected from AC. This is the reason for most of the dust build up in my photos above.
If you can measure current into your depleted GC-2's, I'd love to hear how it performs at full throttle.
How long and what thickness DC cables are you using to battery terminals? YOu might want to set voltage a bit higher than 14.8v to account for voltage drop on those DC cables at ~60 amps output. Since you are generator charging, this might allow slightly shorter generator run times for more charging.
If you can also check battery temperature, I have found my low resistance AGM battery heating up more than expected when high amp recharging, and it retains much more heat than expected during discharge too, especially if I am asking a lot from it overnight. GC-2 batteries are higher in resistance and will heat up even more than My AGM.
The battery temperature plays a big part in choosing ideal battery absorption voltage, and battery temperature is often way higher than ambient temperature, especially when they are always charging or discharging.