Meanwell LSR-350-36 charger question

I just built a new battery pack. Two sections each 12P 7S of used Tesla 18650 cells? The two sections are run in series and connected in parallel for charging. I purchased a new Meanwell LSR-350-36 power supply and adjusted the output down to 29.2 volts. When connected to the battery the output voltage drops to match pack voltage, as expected, but does not increase over time.
I put an amp meter on the battery lead and measured zero amps but saw periodic pulses (too fast to read) of current. Is this the "hiccup mode" that Amberwolf has referred to in several posts?
I assume that the Meanwell is seeing the empty pack as a short circuit and will not charge for this reason. Can I add resistance in series with the output to enable the Meanwell until the pack climbs to a point where it limits the current?
I ordinarily never run my packs this low but since it is a new build I wanted to wanted to find out how much range I could get and check the low voltage cutoff.
Here I am with a new bike and no way to charge it

most of the power supply's (unless they are c.c) will do that. they think its a dead short and will go in to fault or protection mode. "Protection type : Hiccup mode, recovers automatically after fault condition is removed" you can use a current limiting board inline with the power supply to solve this, although I've personally never had any luck with the cheap c.c. circuit boards for sale.

I just went to the shop and dug out two 1 ohm 100 W resistors and put one in each of the positive leads from the half packs. The Meanwell is now charging but only at 7 amps (3.5 Amp to each half pack).
Any ideas about how high the battery voltage needs to be before the it limits it's own current and I can remove the resistors?

Yes, sounds like hiccup mode.

You could use a resistor in series to limit the current but the resistor will get really, really hot. It would need to be a very large one.

Another approach would be to lower the voltage setting on the Meanwell until it can stay on, then increase the voltage later as the charge comes up.

As soon as the pack voltage gets up to whatever the supply voltage reads with no load, the current will start to drop off. For 12s, around 50.4v if you are charging to 4.2v/cell.

You might consider getting one of those chinese dc-dc converters that will limit the current. Some have built in volt/amp meters. This would probably be the best solution without getting a new power supply.

Here is an example without meters:
https://www.ebay.com/itm/DC-300W-20...m=273212826254&_trksid=p2047675.c100752.m1982

Thanks for the link fechter. It is charging now. The output is split between the two 7S battery halves and I put a 1 ohm 100w resistor in series with each of them. The resistors are warm but not to hot to touch and they are built into their own aluminum heat sink box. This is actually an old dump resistor set up from back when I was building wind turbines. Each resistor is only seeing 3.5 amps.
The question now is how low can I discharge the battery before this becomes a problem, or will I have to always leave the resistors in the circuit.
If I purchased the buck converter you linked, would it not also have to have a resistive load in order to start?

100W resistor is a big honker. Since you have them already, I guess that's a workable solution. You may need to always use the resistor with that model of power supply, but you could experiment to find out.

The dc-dc converters come in all kinds of flavors. The one in the link has CC-CV, so you can set the current limit to something less than the Meanwell's and it will work regardless of the battery level. They also have boost converters that would allow charging the battery as a 14s without splitting it while still using the same Meanwell.

The chinese converters tend to have exaggerated power ratings, so pick one that is about 2x what you really want and it might still need a small fan.

If you can, I'd see about exchanging the LSR for an HLG- or ELG- meanwell LED PSU, in the adustable (-xxA) version. Then there's no workarounds, just set it to the max current you want to see, and the max voltage, connect, and go.

Yeah, they're more expensive, but less trouble, and environmentally sealed so no fans to break (and potted so no parts break from vibration if carried around).

The 350 part of the model number of that Mean Well, means only 350 watt output max ?
Is so you probably want a bigger watt power supply.
I forgot the math right now, but being only 350 watts of , Max , output power is probably the reason you are seeing only 3.5 amps of power going into each battery. ( 7 amps of charge current )
You would think since apx 30 volts x 7 amps is only around 210 watts , but there are other factors involved , which someone else here can explain better than me.
So it's time to get a bigger ( watt ) power supply, and if you have the money a larger wattage charger,
I just a few weeks ago bought the best charger I have ever owned, charges packs up to 8s, so you can easily charge two 7 s packs in parallel.
Since you made your packs 12 p, you would not be able to balance charge, unless you soldered balance wires to each cell then soldered them together to a single JST-XH balance connector.

The iSDT T8 is a great little charger.
It is small in size , but puts out allot of charge power, it's fan works very good as well, fan operation on and off several times during charging to keep it running at such high charge rates.

ScooterMan101, tell me more about your ISDT T8 charger. I had not seen that one before.
I do have 7s balance cables installed on the two half packs so it would be simple enough to parallel the two for balance charging.
edit: what are you using to power it? Do they also offer an AC power supply? If so what are the voltage and curent requirements of the power supply?

I have only had it for about 2 weeks now and have only done about 5 charges with it.

Before that I used a 1-8s charger that only went up to 150 max watts of charging, so I only charged one battery at a time.
Now
I charge two batteries at a time in parallel.

Charging 2 6s packs with a parallel charge board, and
just 2 days ago charged for the first time 2 7s packs using parallel JST-HX balance adaptor cable. (along with my home made parallel red and black main charge/discharge cable )

I am still using my Mean Well SP 240 12 that I have had for the last couple of years,
it puts out about 12 volts DC, adjustable a little , I have it adjusted to just a little over 14 volts. It will not go any higher than that apx 14.3 volts. the 240 is for 240 watts max.

When charging the 6s packs together I charge at 12 amps ( 6 amps each ), since the batteries are 5,800 mAh each.
I will be experimenting with the 7 s packs and start riding my e-bike again, once the fires and smoke clear from our California Skies.

The iSDT T 8 can take a DC input of 12 to 40 volts, so if you live out in the country and want to get 3 12 volt Deep Cycle Batteries, or 6 used golf cart batteries and charge them with a solar panel or two you can get up to 1000 watts of charging power !
With a 12 volt power supply you can only use a fraction of that , I forgot the formula, but in simple terms ... the higher the DC output of a power supply that goes into a charger the more of the stated watts of the charger you can charge at.
I was warned to not take 2 Mean Well's and put them together to make 24-28 volt input into a charger because by putting the two P.S.'s together in parallel there is no " Protection " I did not ask what that means since at that point I had been told so much about so many figures that my biological circuits were over loaded , but I regard the advice as being very solid advice.
The place I bought the iSDT from also sells a 24 volt power supply that would be very good to match to the T8, however the T8 is already apx. $ 100 and the 24 volt power supply was another $ 100 , I can only spend so much each month , so I will still use my 240 watt Mean Well, until I get the nerve to solder the circuit board on my new ( refurbished ) 750 watt HP Server Power Supply.

At that point I can then charge 4 batteries at a time.

If I lived in out in the country though I would just get 2 or 3 deep cycle batteries and a solar panel or two instead of a expensive power supply, since you can then use those items for other electrical needs around the home.

I can post links if you want them, however when I post a link to any vendor of any product , there are fans of other vendors that feel their favorite vendor is left out.

Bottom line is you want the largest wattage rating of a charger , and the largest DC imput as well.
and for a Power Supply you want the largest wattage, and if build as a single unit the largest DC output you can get.

Right now with the one Mean Well P.S. that you have I would guess you could charge ( if you get the iSDT T8 charger ) 14 amps easily and perhaps 16 amps to 17/18 amps.

When at home or on the road in my RV I do all my charging via solar panels but I'm getting this new bike set up for cross country touring. The ISDT T8 is appealing in that I could occaisionally balance charge and it has the capacity to charge faster. The down side is that I would still have to carry a Meanwell big enough to feed it.
I googled a link to BangGood (poor choice of names?) is that where you bought yours?
What is your overall impression of the quality and ruggedness of the unit?

I buy my RC charger and other stuff , ( not including batteries which I buy from H.K. ) from
either
Aloft Hobbies
or
Progressive RC
or
Buddy RC


These places will have the latest updated version of the T8, ( the first version did not always balance all cells the same, this has been resolved on the latest 3rd version of it )

I would not buy this charger from Bangood or H.K. as they do not have the customer service that the 3 better , U.S. based business have.

My impression is the Quality is very high, better than the 2 other Lipo/Balance Chargers that I have .
For traveling I would fully put any charger in one or even two layers of foam , on all sides, then take the charger out for when in use.

I have bought a refurbished HP power supply that is probably the same or most likely even smaller than your Mean Well, it is very light weight. You would have to solder to it the Positive and Negative Wires/Plugs into the circut board and solder the far 4 left solder parts on the board, but it is sold at a very low price, since there are Thousands of them lying around.

You can see it here. https://www.itcreations.com/catalog.asp?s_s=511778-001&search=Search

Or for one that has already been modified to use ( but out of stock at this time )

http://lipoconnectionsolutions.com/HP-12v-62A-750w-Power-Supply-4mm-EC5-XT60-XT90-HP12750.htm

Read all the reviews, watched all the videos, I've got to try it. Ordered from Buddy RC.
"I try to make all my impulse purchases right away"

If you do buy the iSDT T8, it uses XT 60 connectors,
so
For plugging in the Batteries to the Charger , if you use the usual male 4mm banana plug from batteries into the female that is on most chargers.
for the T8
Buy the Male XT60 ( into the charger) to Female Banana Plug Charge Adapter. $ 3.99

Then for the wires from the power supply into the T8 another Male XT 60 plug ( which confusingly is really female 4mm gold bullets inside the " Male " outer plastic casing which is then called a Male XT 60 plug , confusing .
XT 60's are called male or female according to the outer plastic part, not the inner 4mm plug .

So it is good to get some 12 awg wire, XT 60 connectors , and the already made $ 4 Male XT60 to Female Banana Charge Adaptor.

Best to call Buddy RC right away then and add to the order the XT 60 connectors, the charge plug adaptor, and some 1-2 meters of 12 awg wire red and black, for when you need that as well.

I can't find how the state of charge was in the the beginning ? Voltage ? Plus at 12p how much can you charge at ? Amps wise ?
What no pics of the home made pack ?

You asked for pictures.
It was the initial test of the battery in the new bike so I ran it down to 49 volts to see how much range I could expect and to test the low voltage cutoff.
Charging as I do with the two 7s sections in parallel the starting point was about 24.5V.
24 cells in parallel at a .5 C charge rate would be around 36 amps. I don't ever expect to be able to charge that fast.