Chinese made 12v 6 amp lead acid battery charger info

[dalek1967]

I posted another thread like this for a TV power supply. This is for information purposes for anyone who has a bad one and wants to repair instead of replace. There is no model number on these but internally they appear to be the same, fan being the only difference I can find. If a component is damaged and can't be identified, this may help. One I have has the brand name XinJieBao on the front above the display. The other isn't marked.

My impressions. I can't say for sure on the chips and such but the HV capacitor is a very low quality one if I think. I tried to google it and also checked the Tom's Hardware tier list. It isn't listed. For me, if it isn't listed there in one of the top tiers, it isn't of good quality. They don't list every brand of low quality capacitor made but they do seem to have a complete list of the high quality ones. Of the three chargers I have , one has a brand, others does not. Inside, the difference is the fan. The one with a brand name has a very quiet fan. The one without has a low quality fan. One was bad out of balance and stopped working within a hours use. If it has a red and black wire for the fan, quiet and works well, so far. If it has a blue and black wires, not good. I've already ordered replacement 50mm fans. Fan seems to kick in when charge amps is above about 2 amps.

These chargers actually function quite well as far as design goes. It has a pulse repair feature that I use quite often. It does work pretty well. I tend to use a desulfator once or twice a year tho to really condition a battery. This charger seems to work well enough for day to day use. It also seems to do a good job of maintaining a charge. I've left these chargers hooked to a battery for months with no damage. So far, these are under $20 on ebay.

The pictures are attached. Hope it helps someone. If nothing else, if someone is planning to buy one of these, you have a idea what you will be getting. In a year or so, I plan to replace the HV cap. At least it may make it last longer, if other components are of reasonable quality.

[CapLeaker]

Re: Chinese made 12v 6 amp lead acid battery charger info

Did you put an oscilloscope and a CT on it to see what this “desulfator” is actually doing? I put desulfator in brackets on purpose, because there are too many gimmicks around that claim do desulfate, but are worth sh*t. I’ve built quite a few desulfators, but mine are much bigger than that and you can hear the battery posts humming. I can’t see this thing doing much besides increasing the charging voltage a little bit. I suppose you get that same effect with an old battery charger and let the battery boil for a bit.
Not that I wanted to dump cold water on this, but I’d say you have more luck desulfating a battery using a small electric fence spiker.

[stj]

Re: Chinese made 12v 6 amp lead acid battery charger info

that actually looks really good inside.

as for trying to get crystals off the plates, i cant see anything there that would do it.
the best devices for that do things like dumping huge inductors into the battery to create current spikes.
you wont do that with a switching psu.

[dalek1967]

Re: Chinese made 12v 6 amp lead acid battery charger info

The circuit I built mine from is open source. I downloaded the gerber files, had the boards made. Then I put the components on it that I got from Newark or somewhere and tested. There is videos where people, including the guy that did the circuit, have put scopes on it and it does produce a spike. The one I built has a diode and capacitor that holds that spike so you can tell if it is finished desulfating or not. If you measure the spike and it is 28 volts and hours later it is still 28 volts, it has likely done all it can. If the voltage is still dropping, it is still working. I've had batteries that were weak start out with spikes around 40 to 50 volts. When done, I've seen it as low as 25 volts or so and holding. Some batteries go lower than others. Difference in way plates are made or something I guess.

I have a battery that is around 20 years old. It was my car battery 2 or 3 batteries ago. I been charging it on occasion since I used it to jump start a old mower but it was weak. When I built my first desulfator, I tested it on that battery. I tested it using a fence charger as a load that was out in the woods. I had a deer food plot out there. At first, it would run about 2 days. It would be really run down tho. The fence charger would just barely do it's thing. After a few cycles and putting the desulfator on it, it got up to where it would last a week and still have a good charge left on it. I'm tempted to see if it would start my car again. It holds a charge very well now.

I did buy some small desulfators off ebay. The coils are really small. I'm not going to say they don't do anything but I suspect it doesn't do a lot. I'm not sure these battery chargers do any better really. No way to really test it. The ones I built tho, I'm sure they work. I just figure the chargers do enough to use in between times of using the desulfators I built. The biggest reason I got these chargers, you can leave them connected all the time and not overcharge the battery.

The coils on the ones I built are about 1.25 inches by .6 inches on a ferrite core. I've thought about making one like I saw on a video that are really large. The larger the coils, the more current the spike pushes into the battery. Supposed to work faster. The guy in the video used it on some really large batteries. That may be to big for my little batteries. Still, I've thought about. Likely have to hand make the coils tho. The ones I got from ebay, the coils are about the size of the tip of my pinky finger. Can't expect much out of that.

I have a friend that has a real expensive fishing boat. It has like 3 or 4 batteries on it. It has a expensive charger on it and it has a desulfator built into it. He says his deep cycle batteries last at least a decade or so before he replaces them. On his previous boat with just a old transformer type charger, he'd replace the battery every 3 to 4 years tops. Some claim desulfators don't do anything. At first, I was skeptical myself. After using it on several batteries over the years, it's hard to argue they don't work. As you say, there are some that are just junk. It's why I made the ones I use.

Thinking about posting pics of the boards in another TV I have. Might help someone if a cap literally blows up.

[redwire]

Re: Chinese made 12v 6 amp lead acid battery charger info

Helps to see pics of the underside of the board, where the IC's are.

The SMPS runs steady to power the front panel, fan etc. and there is a rectifier - the SSP7509 extra mosfet must do the pulse generation.

It looks the same build as another chinese charger I bought. Fair quality, oddball semiconductors and built for very low cost.
One problem is the inrush current is very high, loud ca-bang when you plug it in as there is no NTC or resistor for the primary cap. The two caps run hot, they are stressed. 6A output is a bit optimistic. It should have second fuse F2 populated so a short does not burn it up. There is no Y-cap to prevent a little zap when you touch the car, no EMI filter CM choke, X-cap etc.

Out of the 10 reasons lead-acid batteries fail, sulphation is but one of them. This has been is known for over 100 years, everything tried.
I looked at research papers using electron microscopes to look at the crystals because they are also the cause of lead-acid battery charge lifetime being like 500 cycles. Every discharge cycle, sulphate crystals form until the plates are pretty much covered.

The crystals can be different sizes and shapes, stuck in the pores of the plates. I did not see really solid proof desulfators work unless they are crazy high in pulse power, kW level. Knocking the crystals off the plates is unheard of, they get stuck there and I think you can only hope to dissolve them a little.

I've built my own desulfators but did not see anything spectacular for results, so I am now a non-believer.

[CapLeaker]

Re: Chinese made 12v 6 amp lead acid battery charger info

I don’t see anything that suggests that there is big pulsing power inside. I only had luck desulfating car batteries with huge power. And even at that it takes a few days in order to desulfate a heavily sulfated battery. Desulfating does work, but like I said, it’s not going to happen with these self powered circuits, or these small chargers. Maybe it will get a battery done in a year or 2. Minimum gotta be a voltage doubler with 4 large caps almost the size of a small coffee cup, 2 caps in series for each side.

[dalek1967]

Re: Chinese made 12v 6 amp lead acid battery charger info

Yes, batteries fail for several reasons. Usually mine fails due to a shorted cell, often in something that gives it a bouncy ride. Sulfation is a common one tho. I didn't think they worked either until I used it on several batteries. The example in post above was only one of many I've done this on. I have seen this work but it does take time. The example battery above was over a two month or so period of time. It did improve pretty fast at first but it took a while to get to where it is now. Despite it being about 20 years old, I believe it would work in my car even tho I replaced it because it tested weak.

There is another board in the charger I didn't take a picture of. I was going to add it to the original post but the edit button is gone or I'm not seeing it. I'll add it here. I guess that is where the brains are but I don't see anything that would create a pulse of any kind either. I read somewhere that it claims it is a 'pulse charger' because it hits 18 to 20 volts for a brief time when it is in repair mode, That may help some but I don't have a battery to test it with. I've already repaired the old batteries I had.

I'm also attaching a couple pics of the desulfators I mentioned. The small one is one I bought off ebay. I don't expect much from it but I've had some success on small SLA batteries, over many months. The larger one is the open source version that has been tested by a lot of people. I've seen people talk about it on forums, youtube etc. It's also the one I used on the battery in previous post. I made ten of these. One doesn't work and I put it in the junk drawer. May repair it one day but I never needed more than a couple at a time anyway. Heck, 3 or 4 would have been enough but ten boards was a good price point.

[CapLeaker]

Re: Chinese made 12v 6 amp lead acid battery charger info

That desulfator with the 2 large inductors, are not good. You can put that on a fresh battery and it will keep it clean, but that is about it.

I think your desulfator in post 1 isn’t a desulfator. I think it is a charger that has a desulfate mode. Probably all it does is ramping up and down the output voltage. Let’s say from 14V to 20V DC. While this mode helps, it does not really desulfate. In order to get the white stuff dissolved from the buss and and the plates, you need power and yet it still takes days, plus I have to water the battery too.

[dalek1967]

Re: Chinese made 12v 6 amp lead acid battery charger info

The one with the large inductors worked on that old battery and several more like it. When you have a battery that can't handle a load for any amount of time, put on the desulfator and a trickle charger to keep the battery charged and over time it is able to last longer and longer until it lasts close to a new battery, it is working. It's hard for anyone to convince me what I see with my own eyes work, isn't working. The one battery I used as a example is only one of several that I've done that with. I might add, many others have built that same desulfator and had similar results. It's how I found the thing, reading about others using it in different places and even found a video by the guy who I think originally made it. People that live off grid and have battery banks use these a lot to make batteries last longer. When you have a dozen or so batteries, lasting longer saves a lot of money.

Still, I've thought about using larger inductors for that thing. I'm talking some really large ones. As I mentioned before, I'd have to hand make those inductors tho. That's quite a lot of effort when what I'm using works, even if it does take some time.

You are very likely right about the battery 'pulse' charger. I have a couple that look like a wall transformer that seems to work the same way. Without inductors and such, there just can't be a true pulse. Still, it could help prevent some desulfation, maybe.

All this said, I wish I could afford or make my own nickel iron batteries. I've read they last for decades and decades with only having to change the liquid stuff in it. Thing is, they are very expensive.

[redwire]

Re: Chinese made 12v 6 amp lead acid battery charger info

The 555 desulfators with "big" inductor are useless - it's not the physical size of the inductor- it's the current peak that sets the battery's pulse current. I have built and experimented with those types. A battery has huge capacitance so a several A in an inductor is nothing noticeable.

If you could dump even a 20A impulse into a battery, it appears not enough to dislodge sulphate crystals. They are mineral insulators embedded into the plates and require a major blast to move them.
I think you need at least 50A impulses, whatever you can pump in before causing gassing. Or maybe the gassing is what displaces the crystals?

Note OP's charger has no impulse inductor so I'm not sure what it's doing. The extra small mosfet with no heatsink might be part of it - but still, not enough power.
Beyond a good charge+equalization, I'm not sure a battery would recover much more. Some smaller sulphate crystals do apparently dissolve with a good charge+float for a while. But this is really rare, I've never seen it.

[dalek1967]

Re: Chinese made 12v 6 amp lead acid battery charger info

Thing is, my real experience says it did. I've had several batteries that were weak to the point they were about useless and after a lot of desulfation, they work very well. No battery will return to 100% new but they do get to a point where they can be used as intended. It does take a lot of time tho. A car battery can take months of desulfation to get back to a usable state. One of my biggest uses, preventing sulfation. I do the same as off grid people do. I use these on a regular basis to prevent sulfation from building up to levels that causes a battery to get weak.

The small ones I bought off ebay, they help a little on a small battery, like a SLA battery with a small amp/hour rating. Even that takes a really long time. I don't use them anymore. They just way to slow and for larger batteries, almost pointless. They not much use on small batteries either.

The battery charger, I think their pulse is just a split second increase of output voltage to around 18 to 20 volts. To be honest, I bought these for the smart part since they can be left charging even after being fully charged and not damage the battery. The repair part, I don't really care about. That part we agree on. If it does anything, I don't think it is much. I don't see anything inside that even indicates it could do anything.

Either way, I hope the pictures of the inside will help someone one day. Maybe just the HV cap goes bad. It's likely that anything else would be cheaper to just replace the whole charger. Except maybe the cheap fan.

[stj]

Re: Chinese made 12v 6 amp lead acid battery charger info

has anybody tried ultrasonics?

[dalek1967]

Re: Chinese made 12v 6 amp lead acid battery charger info

I never have but I do have one large enough to put a car battery in even. It has four of the noise makers in it. I call them that for a reason. It is really loud. Cleans my eyeglasses spotlessly clean in seconds. lol I bought it because a carburetor will fit in it easily, even a large 4 barrel one. Cleans firearms in just a few minutes too.

Next time I have a battery in bad shape, I may try that. After all, nothing to lose really. I'd think it would do something but not sure just what. It may be good, may not. May end up with a shorted cell. It's a lot of vibration. I don't think batteries are designed for that sort of thing.

Skeptical but worth a try. Now to find a battery I can play with.

[stj]

Re: Chinese made 12v 6 amp lead acid battery charger info

maybe build one and insert the element into the cell from the top.
if it works, you probably need to flush the battery out and refill it.

a good video for seeing inside a shit battery btw.
these russians to great stuff with cars.
https://www.youtube.com/watch?v=iqGjhYMznLU

[CapLeaker]

Re: Chinese made 12v 6 amp lead acid battery charger info

has anybody tried ultrasonics?

I've got a larger ultrasonic cleaner that could hold a regular car battery. Never had the idea to put a battery in it... right now I don't have a sulfated battery to try, but I'll keep it in mind.

[dalek1967]

Re: Chinese made 12v 6 amp lead acid battery charger info

I have learned something else about these chargers. If you leave a battery hooked up but have a small load on it, the charger will charge until the charge is complete then it cuts off. That's normal and expected. Thing is, if the battery charge drops because of the load or the surface charge moving deeper, it has yet to cut back on and top the battery off. Basically, once it charges and cuts off, it's off. The display is on but that's it. I confirmed this by measuring the voltage on the battery. Most trickle chargers I've ever seen have a low to mid 13 volt standby voltage on them. This 6 amp charger does not.

I have one that looks similar but is a 2 amp model, no fan on it, and it will cut back on if the battery charge drops. It will also trickle charge but if it falls below a certain level, it cuts back on in charge mode and tops it off. Once it tops it off, it returns to trickle mode. It will repeat as needed.

The point of this, if you buy a 6 amp, maybe other larger amp models too, keep in mind that when it is done charging, it ends its job. It doesn't seem to trickle charge or anything. It has yet to cut back on if the battery charge falls. To just charge a battery, the 6 amp model does fine but once it is charged, that's it. The bad thing of this, if a person is charging a battery that has discharged quite a lot, as the charge goes deeper in the battery the voltage will drop, slowly. This charger will not notice that. You have to disconnect the cable or unplug the charger to make it reset and charge again.

I have a PowerTop smart charger, 25 amp model, from Amazon. I love that thing. I've charged tiny batteries and large batteries with it and it has never failed. It notices a shorted cell fast too. It will charge, trickle charge, kick back on if needed and repeat as needed. Plus it gives a really deep charge with the first charge since it charges until the amps is only a 1/4 amps or less. Thing is pretty smart.

I ordered me some Japanese caps to replace the ones in these little Chinese made chargers. That cheap brand makes me worry.

I really hope this info helps someone, either avoid these chargers if they won't serve their purpose or at least know what to expect.

[redwire]

Re: Chinese made 12v 6 amp lead acid battery charger info

It is a big problem for people using them in RV's.
The charger completes its sequence and makes it to float/maintain mode yet (RV) loads get turned on and off, and the charger does not notice, so the battery ends up losing, gets discharged.

It's a common software error with smart chargers. The RV people were having unexplained dead batteries and they only last 1-2 years max.
I would say the chargers need to backstep and re-initiate charging if the voltage falls.

I have this cheap chinese 2A charger and it's super simple in operation, no MCU. It charges to 14.4V then drops to 13.8V when battery current drops off. If charging current goes back up, it seems to reset and push to 14.4V again, then roll back to float 13.8V
It needs new capacitors but I might just build my own charger, I want WiFi to remotely see what's going on.

[dalek1967]

Re: Chinese made 12v 6 amp lead acid battery charger info

That's one reason I wanted to post that. In most situations, that may be fine. Just want to charge a battery right quick and then put it back on a mower or in a car to run it. In a RV, which is a good example where this would be a serious problem, these chargers would not work the way one intends for it too. My PowerTop charger would do the job a lot better, has more amps etc but mostly because it monitors the battery. I might add, this is something I just noticed today.

I wish I could edit the first post and add info as I discover it instead of it being spread all over this thread. Edit button was there at one point but I don't see it on any of my posts anymore. Maybe I made it mad.

[stj]

Re: Chinese made 12v 6 amp lead acid battery charger info

if you have an RV or even a work truck that has a 24/7 device in it like a refrigerator then you should fit a power inlet and a relay+12v psu to switch the load off the battery and onto the mains supply when not on the road.

a friend works at a stupid company where every truck wont work on monday mornings because they are all fitted with 24/7 camera's and tracking that drain the fuck out of the batteries!!

[sam_sam_sam]

Re: Chinese made 12v 6 amp lead acid battery charger info

a friend works at a stupid company where every truck wont work on monday mornings because they are all fitted with 24/7 camera's and tracking that drain the fuck out of the batteries!!

I worked at place that put this crap into their trucks and sometimes had the same issues