Benchtop Power Supply for under $100.

[HaldorEE]

Anybody in the Phoenix area what to share on the price of one of the HRPG-300-3.3? I don't expect to need it for more than a week. If there are enough of us we could just pass it on to the next person.

 

[sshibly]

Here's a link to a $56 30V/10A power supply I briefly ordered after I got to a burn out of my past similar one (which I since fixed via soldering a lose wire) ... which is presently charging one 280Ah cell. Though I canceled my order after my fix, I thought this was good less expensive bet from the reviews: https://www.amazon.com/gp/product/B08B62RXQ7/ref=ox_sc_act_title_1?smid=A2179Y0WCO4CNP&psc=1
P.S. ... Forget about the 5A versions when 10A versions are available for same or similar price!

Captain Bill,
I am sorry, I was in a rush yesterday and could not post the links,

The one above works fine, slow but works, I would get 2 of these and call it a day.

The nice thing about these is that you can make your 12v battery by connecting the cells in series and then:

1 .Charge the 12v battery with a 12v charger till one of the cells reach max voltage.
2. Stop and then charge individual cells to top them off with the 30v10A CC/CV power by connection them individually to each low cells and charging them at 3.6 v,


Meanwell HRPG - This could be used both for charging one cell at 3.x volts or a bunch of cells in PARALLEL.

I was confused about how the Meanwell will react when charging,

Read this post on the ebike forum,

Review: Meanwell HRP-600 Series

Review. Bought from Power Supply Emporium on 5/12/2011 Manufacturer: Meanwell (assembled in Taiwan); Product Spec Color: Silvery Aluminum is stock. Size: 208x105x63.5mm, 1.5kg Cost: $168.64 each; no tax. Shipping: UPS Ground shipping @ $19.01. Arrived on 5/17 (5 days later from San Jose, CA)...

endless-sphere.com

Impressive stuff they are doing with ebikes.

Are needing a solution to charge at 3.3 volts? or at 12v?

 

[CU17]

Looking closer at the web link https://www.aliexpress.com/item/33025400349.html? ... I NOTICE; this unit has 95% 5 star reviews /21 reviews (of other version choice/ none for the 0-5v version); & I am not sure if this unit would limit current as a battery charging operation near its' full charge voltage (like a bench power supply does): ... I left this question with the supplier: (followed by what I noted from info. at web site link: for 480W Adjustable Switching power supply with Digital display power supply for LED DC and the 0- 5V 0-60A version (I AM considering this for 3.6v x 60A = 216 Watts of Top Balancing Charge cycles:

My Question (left w supplier) re the 0- 5V / 0-60A version. If used to charge LiFePO4 cells, will this unit act like a battery charger and reduce current when battery reaches set voltage? OR does this type of battery charge require user monitoring and battery disconnect to protect form over charging the Battery?

Info at web link says: ... don't use full load when you use it. We recommend the use power should be 80% of the rated power
The 0-5v 0-60A specs are not included in spec sheet. Attached Info. says: ... When the load device is connected, the current value can be adjusted directly in real time. The maximum current value is the maximum current value of the load device. If the current adjustment knob clockwise exceeds the maximum current value of the device, the digital current value will not last. Real-time synchronized digital display, showing only the maximum current value of the device. ... Uses: Mainly used for various battery charging, DC equipment, DC motor stepless speed regulation, LED stepless dimming, chemical electroplating speed regulation, ... Precautions: *When the charger is used, please unplug the battery and turn off the input power. .. Do not exceed the charging range specified by the battery manufacturer.

I am not sure this will limit current when 3.65 volts is set for a battery charging operation. Some folks here might already know the answer to my question by the "Adjustable Switching power supply" label for unit. I am still learning about these options. ... I will share their answer later, especially if it sounds good :+)

So the way these things work electronically is, that they are always in CV mode unless they get pulled into CC mode. If you have the one with just the voltage adjustment nob and set it to 3.65V on an empty LiFePO4 battery it will deliver its maximum current (as the voltage gets pulled down by the empty battery) until the battery gets to 3.65V. Then it will go into CV mode and trickle charge the battery until it's full.

The one with the additional current adjustment nob allows you to limit the maximum current to something other than the power supply spec. So if you only want to charge at 50A instead of 60A, you can limit that with the current adjustment nob and it'll do CC until it reaches 3.65V when it automatically goes into CV.


You'd only run into a problem if you use a static 5V power supply as it would do a CCCV charge to 5V then.

Two areas of caution:
1. 60A is a lot of current for a power supply that size. So make sure two check it's temperature every once in a while /add an additional fan and don't run it at the full 60A (55 or below).
If you use the one with just the voltage adjustment nob, make sure to periodically adjust the voltage upward instead of setting it to 3.65 directly to manually keep the current below 60A.
2. (On either one) Don't connect the battery directly to the charger set to a high voltage (i.e. above 3.4V). Instead, measure the voltage of the battery, set the charger to a minusculely higher voltage (and if you have the current adjust nob to it's lowest setting) and then connect the battery and slowly raise the voltage. This will prevent huge sparks and damage to either the cells or the charger. It will also allow you to verify that everything is ok.

 

[Capt Bill]

So the way these things work electronically is, that they are always in CV mode unless they get pulled into CC mode. If you have the one with just the voltage adjustment nob and set it to 3.65V on an empty LiFePO4 battery it will deliver its maximum current (as the voltage gets pulled down by the empty battery) until the battery gets to 3.65V. Then it will go into CV mode and trickle charge the battery until it's full.

The one with the additional current adjustment nob allows you to limit the maximum current to something other than the power supply spec. So if you only want to charge at 50A instead of 60A, you can limit that with the current adjustment nob and it'll do CC until it reaches 3.65V when it automatically goes into CV.


You'd only run into a problem if you use a static 5V power supply as it would do a CCCV charge to 5V then.

Two areas of caution:
1. 60A is a lot of current for a power supply that size. So make sure two check it's temperature every once in a while /add an additional fan and don't run it at the full 60A (55 or below).
If you use the one with just the voltage adjustment nob, make sure to periodically adjust the voltage upward instead of setting it to 3.65 directly to manually keep the current below 60A.
2. (On either one) Don't connect the battery directly to the charger set to a high voltage (i.e. above 3.4V). Instead, measure the voltage of the battery, set the charger to a minusculely higher voltage (and if you have the current adjust nob to it's lowest setting) and then connect the battery and slowly raise the voltage. This will prevent huge sparks and damage to either the cells or the charger. It will also allow you to verify that everything is ok.

for under $80 , if you have time to deal w Sea Freight from China ... This feedback has me thinking; This would be a great tool to have if you are top balancing 280Ah LiFePO4 sets ... like in helping friends get into LiFePO4s, or possibly building sets to pass on to others. I'd go for the dual knob 0-5v 0-60A model for that purpose : web link https://www.aliexpress.com/item/33025400349.html?

 

[Just John]

Anybody in the Phoenix area what to share on the price of one of the HRPG-300-3.3? I don't expect to need it for more than a week. If there are enough of us we could just pass it on to the next person.

I'm in Mesa, but probably not interested in the Meanwell supply to be honest. I have a couple of the 18 amp Riden supplies. I also have a 10 amp cheap supply from Amazon that is sitting idle.

 

[Hedges]

In case this might help anyone with burnt out power supply issue: Here's something to check out: I opened up my $65 30V/10A power supply after it sparked and puffed some smoke, then stopped showing out voltage on dial, or producing any current on wires. That happened after I briefly touched its' cables to one 3.2volt cell in reverse polarity with the unit switched OFF (not on). .... After opening it up to look further, I discover one of the main wires of power supply circuit had come un-soldered plus was poorly soldered in the first place. Also saw where loose wire hit frame (burnt smudge). Got my unit back in shape via solder :+)

Some power supply vendors say to use a diode if charging batteries, so power supply doesn't actively pull down battery voltage.
In your case, may I suggest also using a fast-acting fuse?

 

[Capt Bill]

Some power supply vendors say to use a diode if charging batteries, so power supply doesn't actively pull down battery voltage.
In your case, may I suggest also using a fast-acting fuse?

I ended fixing that problem by opening up the power supply to see one of main wires that was poorly soldered to circuit board had come loose, and touched metal to make burn mark. It did not make sense a burn out could happen when switch was OFF. Re-soldering put the Power Supply back in operations; and I am still using it.

 

[Hedges]

It did not make sense a burn out could happen when switch was OFF.

Except with a reverse-polarity lithium cell able to deliver thousands of amps (depending on resistance), it would make sense.

 

[Just John]

Another Update:
I decided to open it up, ok, a couple of loose connections, double checked it all. It's now working as it should more or less. The dial controls suck, and you really have to watch the output with a DMM/DVOM for the voltage.

At least I'm charging new individual cells up prior to topping them and it's working for that. Using new 280AH cells
I'll post back & edit this after it's done and starting on the next.

EDIT: Dec.29, 08:00 EST ish...

Cell	Volt Start	Charge A. start	Charge Volts	Time	End-amp	End V @ terminal	V after 1hr rest
C1 EVE 280	3.37	30.4	3.60	1:10 +/- .05	2.0 +/- 0.2	3.69	3.56
C2 " "	3.32	30.6	3.60	1:00	2.0	3.70	3.62
C3 " "	3.33	30.1	3.60	1:00	1.9	3.68	3.62
C4 " "	3.32	30.2	3.60	1:05	2.4	3.68	3.61

Bottom Line, the Tek Power TP15/40E is working even if finicky.
Back to your Regular Programming ;-)

I finally broke down and purchased the Tekpower TP1540e, and I am somewhat impressed. First thing I did was open it up, it has better soldering than I expected for a cheap Chinese supply. As you indicated, a big pain to get adjusted. I will use it for the bulk charge up to 3.6, then let the Riden finish to 3.65.

 

[Just John]

It is adjustable upt to 3.65 volts but I might go only to 3.6 volts. My cells won't arrive drained. They ship at about 50% and measure 3.2 to 3.3 volts. Earlier I had speculated that I could do a two step process with a different model but this one could do the whole charge. I might be doing 16 cells so if they are at 50% SOC that means I would have to put over 2,000 Amphours into them which could take a day and a half at 60 Amps per hour.

Be careful and don't assume about state of charge, one of mine arrived at 3.3 something and only took 5ah to get to 3.65. That is after sitting in the garage for two months it only took 5 amp hours to get it full. Just an FYI.

 

[Just John]

I use a RC hobby balance charger for my small LiPos that are up to 6 series cells but it can only handle about 4-5 amps. It does great for the smaller packs, but am now looking for something that can handle up to 16 cells series and 50+ volts at higher amps. My benchtop power supply goes up to 300v DC but is not robust enough to handle high amps for long periods so I've been looking at a new PS that I''ll dedicate to just charging.

The 0-30v supplies are easy to find but I need one that goes up to 60v+...most of the low cost 60v stuff is only up to 5 amps, even when turned down to 12 or 24v, so for charging my bigger batteries I'm thinking of using a basic cheap high-amp 60v PS like below and feeding it into either a cheap solar charge controller's PV input, or a DC-DC charger. The 600w version should be able to charge a 12/24v battery at near 50/25 amps, or double that for the 1200w version. The CC or DC-DC charger can then handle the charging parameters instead of relying on a monitor-to-cut-off relay (which would be wise with just a

Check out the Riden RD6018, 60 volts at 18 amps and a great interface. He only sells an 800 watt supply, but a 1200 watt version that also fits in the case is only $5 or $10 more and would allow the full 60 volts at 18 amps range. The 60 volts at 12 amps (RD6012) works great with the 800 watt supply he sells, but I haven't run it at 60v. However we are talking just under $190 for it rather than under $100.

 

[Just John]

The power supply they sell with it is 800W so you can do 12v or 24v stuff at 18A but not 36v or 48v. It can use any power supply that's 65v+, given a high enough wattage. But over 1000W PSUs probably won't fit in the housing they offer.

I ordered a couple of 1200 watt supplies from claim to fit in the Riden case, I will let you know when I get them. Meanwhile the 800 watt supply Riden sells with the kit works for 18 amps at lower voltage.

 

[Just John]

This guy claims to have a 1200W that will work with the Riden 6018- https://www.aliexpress.com/item/1005001628048561.html

I didn't buy one

I will let you know how it works when it arrives in a few weeks.

 

[Just John]

Cheaper by $20 compared to NVVV 1200W

the reviews say noisy fan, FYI: an upgrade to a nice ball bearing fan will solve that. Sometimes it is hard to the little fans, Thanks,

FYI, Noctua sells a good fan that fits. Moves more air and is significantly less noisy. I just tried one in the 800 watt supply. 60 mm, 12 volts at .1 amps.

 

[Ampster]

Just an FYI.

Thanks, I have seen the run from 3.45 to 3.65 many times and had my share of slight overcharges. Fortunately I haven't bloated any by those mistakes.

 

[Just John]

Thanks, I have seen the run from 3.45 to 3.65 many times and had my share of slight overcharges. Fortunately I haven't bloated any by those mistakes.

Yes, one of the things I like best about the Riden is that it turns off reliably, and tells you how many AH it put in.

 

[markver]

Yes, one of the things I like best about the Riden is that it turns off reliably, and tells you how many AH it put in.

+1 for the Riden RD6012, very accurate, solid unit.

 

[Cannabat]

I ordered a couple of 1200 watt supplies from claim to fit in the Riden case, I will let you know when I get them. Meanwhile the 800 watt supply Riden sells with the kit works for 18 amps at lower voltage.

My RD6018w kit arrived a week or so ago and has been put to good use. Charging my LiFePO4 cells, running a CB radio, charging my car battery, and helping to diagnose a parasitic draw issue on my car when using a multimeter and ammeter weren't quite enough for the situation. Really like it, easy to use.. The battery charging mode is great. Please do update when you get the 1200W supplies in.

I hope Riden upgrades to a 40+ amp supply at some point, keeping costs reasonable.

 

[Dzl]

In under two years (I think) they have stepped up from 6A to 12A to 18A, with 24A rumored to be the next iteration. at that rate it'll be a few more generations before they get close to your hopes of 40A, but if they keep their current pace, it won't be long . I'm not sure it'll work out that way though, the economics and demand may not scale linearly. I'm holding off until 24A to purchase if I can sit on my hands long enough. I'm in no real hurry to buy since my primary project has been derailed for the time being.

 

[Just John]

In under two years (I think) they have stepped up from 6A to 12A to 18A, with 24A rumored to be the next iteration. at that rate it'll be a few more generations before they get close to your hopes of 40A, but if they keep their current pace, it won't be long . I'm not sure it'll work out that way though, the economics and demand may not scale linearly. I'm holding off until 24A to purchase if I can sit on my hands long enough. I'm in no real hurry to buy since my primary project has been derailed for the time being.

I know he is working on a 24 amp version. The 40 amp version would mean over 2400 watts to get the full 60 volt range. I am really pleased with them except for the cheap fans. There is a tweak to the standard 800 watt supply to make it slightly more efficient and last longer. I will check the 1200W supply, even though truthfully I have no use for 60 volts at 18 amps. Jerry Walker does a bunch of videos on it, including building a linear supply for it.