应该是电池反冲了 BATTERY RECOIL, BATTERY BACKLASH

[Texas-Mark]

Sure whatever floats your boat.

I guess you have not read all of the horror stories here of receiving damaged batteries, etc. <shrug>
Besides, I can just zip over to Houston and see what I am buying in person.

 

[ArkCabinMan]

Because there are some good deals to be had if you don't mind waiting, and most likely the majority of people have no issues. I've made about a dozen purchases and never had any problems. That said, there are certain things I won't buy there. Batteries, and anything over $100 or so.

Fair enough..!

 

[Goboatingnow]

I have a 10 amp Wanptek PSU.
Before I connect to a battery, I usually turn the output on for a few seconds, and then connect. The reason is because I think these have capacitors on the output. If you just connect a battery, it may charge the capacitor too fast. By turning on the output first, the capacitors are pre-charged.

You should always have a diode in the bench psu feed to the battery

 

[Bob B]

I guess you have not read all of the horror stories here of receiving damaged batteries, etc. <shrug>
Besides, I can just zip over to Houston and see what I am buying in person.

From what I have seen so far ..... most of @Goboatingnow 's experiences are absolutely the opposite of most other people.

 

[Goboatingnow]

From what I have seen so far ..... most of @Goboatingnow 's experiences are absolutely the opposite of most other people.

Yup, how many people had their mast get hit three times in 4 minutes by lightening ! ( or 500 plus orders with AliExpress , over 5-6 years )

 

[Vigo]

So i read up to this point and my main reaction is 'most psu specifically swear off battery charging because bad things are likely to take place without special precaution and if you have to ask please just dont buy this product from me'. Not that i'm not sympathetic. I learned most of what i know the hard way. But THATS WHY I BUY CHEAP STUFF!

But i also noticed noone challenged the concept of 'battery recoil/backlash'. My gut reaction is it's complete BS but i decided to google the terms and see if someone had a plausible explanation for this scapegoat concept. All i found in a minute was this pretty decent article about people catching their boats on fire, which is vaguely relevant because it has to do with not being aware of all the variables leading to equipment failure, which could lead to fire.

Battery Backlash: Nigel Calder Weighs In on LI Technology

'We Are Not Seeing a Rash of Lithium-Ion Catastrophes'

loosecannon.substack.com

 

[Texas-Mark]

But i also noticed noone challenged the concept of 'battery recoil/backlash'

In my 40+ years of electronics, I had never heard the term before. Even that article you linked to only uses it in the title.

 

[Vigo]

Yeah, it's ironic that the search was technically failing to match anything, yet still took me to something which was relevant in terms of mismatching equipment and settings leading to damage.

Glad to hear this wasn't a huge blind spot in my case. Sounds like it's pretty much made up as an excuse, or at least a translation issue.

 

[Goboatingnow]

There are good electrical reasons why cheap PSU s shouldn’t be used to charge batteries , the ouout circuitry is not protected against the battery terminal voltage as a psu expects a load only. Some bench supplies have specific protection ( usually called OVP, over voltage protection ) which facilitates battery charging , some don’t

If the Waptek one didn’t have OVP , charging batteries would kill it. I wouldn’t place much store in the Chingish “ blacklash” term

Ask them in the psu had OVP. , that’s the issue.

 

[Ampster]

Some bench supplies have specific protection ( usually called OVP, over voltage protection ) which facilitates battery charging , some don’t

Some PSU s also do not have current limits and that can be a problem when connected to a battery as well since the PSU will attempt to respond to the load of the battery and go over current.

 

[dweick]

...

Secondly running the supply continuously at max rated output and it blew up. Funny that , did this not cross your mind , what do you expect for the money , Tektronik !

Yep, for the money I would expect Tektronik.

For a lot more money I'd expect Textronix.

 

[Goboatingnow]

Yep, for the money I would expect Tektronik.

For a lot more money I'd expect

Great engineers can’t spell didn’t u know that , we’re numbers people ?

 

[cods4]

I'm only up to 52 purchases from Aliexpress, some of them have been many 100s of dollars, but I would have to agree with Goboatingnow. My experiences have generally been very good.

I have a wanptek 60V 5A power supply and I find if I connect it to the battery while the unit is off, it creates a bit of a short circuit (luckily mine survived though). So I always turn it on and set it to the correct voltage before connecting the battery.

 

[cods4]

Yep, for the money I would expect Tektronik.

For a lot more money I'd expect Textronix.

Almost got it. *Tektronix

 

[Vigo]

I have used a good half dozen ‘meanwell knockoff bench psus’ to ‘charge’ batteries and ive found them to be acceptably durable as long as current spends most of the time under max limit and you arent constantly making and breaking connections. Much like an inverter, its not much of an issue if its ALWAYS connected to the battery.

I say ‘charging’ because about half the time im feeding in less current to a battery circuit than what is coming out as load, so its more like transferring power from one source to another but not always actually ‘charging’ the batts in question. Anyway it works well enough for me that i continue to do it. If you use them cautiously i think they are good value.

 

[Goboatingnow]

I'm only up to 52 purchases from Aliexpress, some of them have been many 100s of dollars, but I would have to agree with Goboatingnow. My experiences have generally been very good.

I have a wanptek 60V 5A power supply and I find if I connect it to the battery while the unit is off, it creates a bit of a short circuit (luckily mine survived though). So I always turn it on and set it to the correct voltage before connecting the battery.

Preferably set it to a slightly higher voltage.

I don’t think these psu have good OVP that’s the issue. Many cheap bench psus don’t have good OVP. The OP didn’t understand this distinction and blew his as a result. Moral , unless you understand , don’t charge batteries with a bench psu.

( it’s all to do with the mosfets in the psu output circuit, never reverse bias mosfets !! )

 

[gonmag8]

Does this mean one shouldn't just unplug the psu from the mains once charging is finished? I was thinking of using a mains timer but reading this it might not be the best idea?

 

[Goboatingnow]

Does this mean one shouldn't just unplug the psu from the mains once charging is finished? I was thinking of using a mains timer but reading this it might not be the best idea?

Some psus cannot handle a voltage being impressed on their terminals end of story. As a minimum ensure the psu is never reverse biased , by ensuring it’s set voltage is at or above the battery voltage, the trouble is as the charge proceeds the battery terminal voltage rises and a psu without OVP will fault.

 

[gonmag8]

Thank you, would it be an idea to use a Diode in series to the positive line ?

 

[cods4]

Thank you, would it be an idea to use a Diode in series to the positive line ?

Yes, although it would probably make more sense to use a fuse instead. Then you don't end up with a 0.7V drop.