This critter can be found on eBay. It is a switching type power supply.Supposed to have an ultimate amperage potential of 33, voltage adjustment of 10, to 15, and work fine as a long term battery CHARGER as well as a power supply. The unit has good reviews.I read all the time on this forum about folks PARALLELING their switch type "converters" to increase total charging ampacity.But the -supplier- of this switched unit says to not connect more than one to a battery or they will "burn out".I simply do not have the experience with PWM switch controlled power supplies to appreciate -why- car battery chargers yawn at being connected in parallel to a battery or bank and yet this one would "burn out".Would not an appropriate electrolytic capacitor serve to suppress the amplitude of whatever ripple the PWM frequency operates at?Only experience can yield an answer to this. I sure would like to travel with a 66-ampere charge rate in a small toad.

Small Problem.That is exactly the kind of thing that is a bad battery charger. It is a constant and regulated voltage. You want something that can time or sense the battery situation. Trust me please, I did boat work before the depression and I have seen and repaired a lot of this. Another problem is that even if you parallel two and they survive (a good chance actually), you will only get your 66amps for a short time. Even to get that, you will have to set a charge voltage that is dangerously high. As soon as the bank terminal voltage comes up, you will loose charge rate. If bump the supply voltage up, you just over heat and boil the batteries to death. In times of old, a regular converter was just this sort of thing (but the stone age version) and they destroyed more battery banks than I could count. Matt

Matt, you should know Mex by now. He's MORE than familiar with charging batteries with a manual charger which is what this is. You regulate the voltage by changing it by hand.

From Mean Well's website for one of their supplies:B3. If we need a 600W output, can we use two units of S-320 connected in parallel?Ans:No, you can not do this connection because S-320 is not equipped with the parallel function. When two power supplies are connected in parallel, the one with higher output voltage will share more loading and deliver more (even "all") power to the load and cause these two power supplies to be unbalanced. We suggest using PSP-300 or PSP-500 because it is equipped with the current sharing function.I guess it depends on how they handle overcurrent conditions.You'll have to give it a try to see if the current limit works by rolling back the voltage, or latching off until the load is disconnected or the power supply power cycled.I don't see how it would burn out unless the power supply was a '4 quadrant supply' (doesn't just source but can also sink power) which they usually are not.

Mexi knows more about batteries, than I will ever learnHis question really is what he is askingAbout the reliability of two PWM chargers togetherI know I have used various combinations power supplies and converted or chargers together and have never encountered a problemMexi do you have a link to the ebay saleI wonder if they meant to say two would burn up a batteryWhich of course would depend on the battery`s involved

QUESTIONS re: MEGA-WATT 33-AMP POWER SUPPLY | Good Sam Community

MrWizard
Moderator
Apr 27, 2014
Mexi knows more about batteries, than I will ever learn
His question really is what he is asking
About the reliability of two PWM chargers together

I know I have used various combinations power supplies and converted or chargers together and have never encountered a problem

Mexi do you have a link to the ebay sale
I wonder if they meant to say two would burn up a battery

Which of course would depend on the battery`s involved
DSchmidt_2000
Explorer
Apr 27, 2014
From Mean Well's website for one of their supplies:
B3. If we need a 600W output, can we use two units of S-320 connected in parallel?

Ans:
No, you can not do this connection because S-320 is not equipped with the parallel function. When two power supplies are connected in parallel, the one with higher output voltage will share more loading and deliver more (even "all") power to the load and cause these two power supplies to be unbalanced. We suggest using PSP-300 or PSP-500 because it is equipped with the current sharing function.

I guess it depends on how they handle overcurrent conditions.

You'll have to give it a try to see if the current limit works by rolling back the voltage, or latching off until the load is disconnected or the power supply power cycled.

I don't see how it would burn out unless the power supply was a '4 quadrant supply' (doesn't just source but can also sink power) which they usually are not.
mena661
Explorer
Apr 27, 2014
Matt, you should know Mex by now. He's MORE than familiar with charging batteries with a manual charger which is what this is. You regulate the voltage by changing it by hand.
Matt_Colie
Explorer II
Apr 27, 2014
Small Problem.
That is exactly the kind of thing that is a bad battery charger.
It is a constant and regulated voltage. You want something that can time or sense the battery situation. Trust me please, I did boat work before the depression and I have seen and repaired a lot of this.

Another problem is that even if you parallel two and they survive (a good chance actually), you will only get your 66amps for a short time. Even to get that, you will have to set a charge voltage that is dangerously high. As soon as the bank terminal voltage comes up, you will loose charge rate. If bump the supply voltage up, you just over heat and boil the batteries to death.

In times of old, a regular converter was just this sort of thing (but the stone age version) and they destroyed more battery banks than I could count.

Matt
Matt_Colie
Explorer II
Apr 27, 2014
Small Problem.
That is exactly the kind of thing that is a bad battery charger.
It is a constant and regulated voltage. You want something that can time or sense the battery situation. Trust me please, I did boat work before the depression and I have seen and repaired a lot of this.

Another problem is that even if you parallel two and they survive (a good chance actually), you will only get your 66amps for a short time. Even to get that, you will have to set a charge voltage that is dangerously high. As soon as the bank terminal voltage comes up, you will loose charge rate. If bump the supply voltage up, you just over heat and boil the batteries to death.

In times of old, a regular converter was just this sort of thing (but the stone age version) and they destroyed more battery banks than I could count.

Matt

Forum Discussion

QUESTIONS re: MEGA-WATT 33-AMP POWER SUPPLY

About Technical Issues

Related Content

Question?

Battery question

Cleaning Question

Cooking question

Fridge Question