Charger Power Supply Safety

[bri4jenn]

I need a power supply that my kids can operate. Safety is of upmost importance. I wanted opinions on each of these options
1) modify an HP server power supply myself. My concerns are around any exposed wires or electric leads that the kids may touch by mistake when it is on. Am I correct this could be an issue. Is there any way to make these power supplies safe? Any video's or links you can share would be appreciated
2) Buy a power supply that has already been modified that has covers over any bare wires and leads like the Motiv MOV3360 720W power supply or BuddyRC 1800W 24v power supply. Are these pretty safe to use with all dangerous things covered? I will still supervise charging.

 

[WickedFog]

Either can be safe. Just use a power strip to turn the PSU on, then all they have to do is flip that switch to turn on the charger. Put the PSU in a safe place where they don't need to be to charge batteries, like up on a shelf, or inside a vented cabinet.

That 24v one looks pretty decent. @Greywolf74 actually has some vids on one he built if I remember correctly.

 

[Greywolf74]

I wouldnt be too worried about using converted DC power supplies. Anything under 36VDC isnt a huge shock hazard. That being said in the right circumstances any electrical source can be dangerous. Personally Id buy something like THIS and then just use some liquid tape or plastidip to coat any exposed areas. As WF stated, use a power strip as an on/off switch for the DC PSU. The PSU I just linked isnt quite as powerful as the one 1800W one you listed but its cheaper and you can customize how many connectors it comes with etc. 1800W is complete overkill anyway for 98% of users out there. My main work horse is only 1100W and I run 3 chargers and about 20ft of LED strip lighting with it. The only time I need more than 1100W is if I'm doing something drastic like parallel charging like tweleve 6S lipos, which I never rarely ever do, or maybe if I was going to charge to do 5C charges on all three of my chargers at once but again almost never happens.

The videos I have are for converting PC power supplies although I have done server power supplies too I just havent done a video for those because the pinouts on all the server power supplies are different and you have to find a map for it so you know which ones to connect together. Also if your running 2 of them in series to get a 24V power supply then you have to be able to find and disconnect the DC case ground on one of the units. Its not something that lends itself to making easy to follow instructional videos.

Heres a couple of the ones I've made

 

[tntpoof]

the only down fall a server power supply is the fan noise.. I mounted mine under my work table hooked to a multi tap

 

[WickedFog]

the only down fall a server power supply is the fan noise.. I mounted mine under my work table hooked to a multi tap

Noctua makes some really good fans that are extremely quiet. I replaced the fans in one of my noisy 3d printers with them and problem solved.

 

[Greywolf74]

Depends on how the server PSUs are built too. If you dont terminate the proper pins then the fans will run at full speed and be obnoxiously loud. If its done properly you can limit the fans to about 30% of max RPM. still a bit noisy but manageable, especially considering the cost savings. The ones made from PC power supplies are quiet.

 

[bri4jenn]

Depends on how the server PSUs are built too. If you dont terminate the proper pins then the fans will run at full speed and be obnoxiously loud. If its done properly you can limit the fans to about 30% of max RPM. still a bit noisy but manageable, especially considering the cost savings. The ones made from PC power supplies are quiet.

How many 24v and how many 12v female 4mm banana plugs would you add to the power supply? I was thinking 2x 24v and 2x 12v. I can select up to 3 for 24v and up to 2 for 12v.

 

[Greywolf74]

How many 24v and how many 12v female 4mm banana plugs would you add to the power supply? I was thinking 2x 24v and 2x 12v. I can select up to 3 for 24v and up to 2 for 12v.

Its kinda hard to say. How many chargers are you planning on running. Will those chargers run on 24V? A lot of chargers will only run on up to 18V so make sure when buying a charger to take that in account. The Hitec charger I linked earlier will only run off of 18V max so if you're planning on going that route Id get two 12Vs for sure. If your planning on getting iChargers they will run on as much as 30-32V (forget the exact amount). How many iChargers are you going to get? Id get a 24V connection for each one you plan on running. You have to be mindful of your charging levels though if you're going to run multiple high wattage chargers like the iChargers off of a single PSU. You shouldnt have much problem as you'll most likely never charge more than 10-12A per battery but if you tried to run two 30A charges at the same time you may overwork the PSU. Youd have to do some math to find out what the max settings would be given how many chargers you're running and the number of cells your lipos have that you're charging. We can cover that later once you figure out exactly what you're going to get and run.

Do you plan on running other things off of it besides chargers? For example if you're running 24V chargers you could use the 12V side to run things like LED strands or really anything that runs on 12V. If it were me Id either go all in and get as many connections as possible for future expansion or Id at least get two 24V and one 12V so I could run two 24V chargers and one stand of LEDs but thats just me. You can always make splitters to run more items also although I wouldnt recommend running the chargers through a splitter.

 

[RustyUs]

HP server power supplies are probably the easiest to covert.

 

[Greywolf74]

HP server power supplies are probably the easiest to covert.

View attachment 136844

View attachment 136845
View attachment 136846

That particular PSU is one of the easiest ones but I dont think any off them are very hard as long as you can get a diagram of the pin outs. I've done two of those as 12V PSUs and I've done a pair of different HPs and a pair of Dells as 24V PSUs.

 

[bri4jenn]

The videos I have are for converting PC power supplies although I have done server power supplies too I just havent done a video for those because the pinouts on all the server power supplies are different and you have to find a map for it so you know which ones to connect together. Also if your running 2 of them in series to get a 24V power supply then you have to be able to find and disconnect the DC case ground on one of the units. Its not something that lends itself to making easy to follow instructional videos.

the only down fall a server power supply is the fan noise.. I mounted mine under my work table hooked to a multi tap

I replaced the fans in one of my noisy 3d printers with them and problem solved.

Is it better to get the power supply with 4mm bullets or the connector the batteries are like EC5? The 4mm bullets may provide more versatility but is there another advantage to using the same connector as the batteries.

 

[Greywolf74]

Is it better to get the power supply with 4mm bullets or the connector the batteries are like EC5? The 4mm bullets may provide more versatility but is there another advantage to using the same connector as the batteries.

Sorry, I dont understand the question. You can only get these types of PSUs with 4mm bullets afaik

 

[bri4jenn]

On this power supply charger Lipo Connection Solutions it does come with a direct connection to XT90 as well as 4mm bullets. If the icharger s6 has XT90 connections is it better to go this route for simplicity?

 

[Greywolf74]

On this power supply charger Lipo Connection Solutions it does come with a direct connection to XT90 as well as 4mm bullets. If the icharger s6 has XT90 connections is it better to go this route for simplicity?

It doesn't matter if you go 4mm bullet to XT90 or go XT90 to XT90. However you want to do it.