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

mena661
Explorer
Jul 05, 2014
Don't have an iPhone but thanks.
SCVJeff
Explorer
Jul 05, 2014
For the iOS folks:
Since all the forum battery guys are prettymuch following this thread, HERE is a link to the Apple Store's Trojan Battery App (iOS). Way more info than the .pdf they released.

Unfortunately it's big because of all the charts and graphics, but worth a gander.

(Edit: added iOS note.. :( )
NinerBikes
Explorer
Jul 02, 2014
Mexico Wanderer, where are you at in building up your power supply based charge system in an ammo box?
NinerBikes
Explorer
May 03, 2014
MEXICOWANDERER wrote:
Solar. Yeah. Last summer, 37 days of total or partial overcast July - August. The hurricane days. Horizontal power poles.

If I can find a good plastic case I am going to "do" a pair of the smaller chargers. Switches and relays. No more fooling with the insides of a Mosler safe-sized ferroresonant 200 amp charger, doing reconnect. Now, to get the grand daughters peddling a bicycle alternator for 60 amps and I got it knocked.

60 amp hours is going to pull a 4 HP 99cc Honda EU2000i down hard up front. 30 Amps will pull a Honda EU1000i down hard up front, heck even my PD 9240, on a 40% charged Trojan T1275, the Eu1000i better be fully warmed up before I turn it on. No way your grand kids can make that kind of power on a bike.
MEXICOWANDERER
Explorer
May 03, 2014
Solar. Yeah. Last summer, 37 days of total or partial overcast July - August. The hurricane days. Horizontal power poles.

If I can find a good plastic case I am going to "do" a pair of the smaller chargers. Switches and relays. No more fooling with the insides of a Mosler safe-sized ferroresonant 200 amp charger, doing reconnect. Now, to get the grand daughters peddling a bicycle alternator for 60 amps and I got it knocked.
SCVJeff
Explorer
May 03, 2014
Hummmmmm.... They ain't answering the fone. Mebbe we can flank em' .. Me and Niner to the West, and Mena from the East. no escape...
mena661
Explorer
May 03, 2014
NinerBikes wrote:

I thought you had it handled with solar too, for topping off purposes. 450 watts, three 150 watt 22 V panels and a PWM controller of some sort, with temp sensing, on your roof.
Haven't bought the panels yet. I have to change some wiring around and make some temporary stuff permanent first. And that's after the spring yard weed cleanup (that part gets old).
NinerBikes
Explorer
May 03, 2014
mena661 wrote:
MEXICOWANDERER wrote:
Automatic means thermistor. Means warping the control circuitry. Have you determined what "float" means amperage wise to your own battery bank Mena? Are not those battery maintenance gizmos temperature reactive?
Trojan has float specs but I only meet them in the spring and fall for the most part. I do have a HF floater with a diode for the really hot stuff but an auto temp comp float would be awesome. Looking forward to getting some solar so this can be accomplished correctly.

NinerBikes wrote:

Where do you store your batteries that it's 43C in the 661 area code? I thought you go to the beach, with onshore flows in your Class A?
I live in the high desert near Edwards AFB. I camp in the cool weather but charging and stuff is done at home in the heat. I do need to come up with something because the Iota shuts off at much over 100 so floating with it is a no go then. No interest in going that far with adding electronics to my chargers. My tweak gene only goes so far with this RVing stuff. :) I would rather tweak my computer! Besides my next project is solar and I have some things to do first to prep for that.

I thought you had it handled with solar too, for topping off purposes. 450 watts, three 150 watt 22 V panels and a PWM controller of some sort, with temp sensing, on your roof.
mena661
Explorer
May 03, 2014
MEXICOWANDERER wrote:
Automatic means thermistor. Means warping the control circuitry. Have you determined what "float" means amperage wise to your own battery bank Mena? Are not those battery maintenance gizmos temperature reactive?
Trojan has float specs but I only meet them in the spring and fall for the most part. I do have a HF floater with a diode for the really hot stuff but an auto temp comp float would be awesome. Looking forward to getting some solar so this can be accomplished correctly.

NinerBikes wrote:

Where do you store your batteries that it's 43C in the 661 area code? I thought you go to the beach, with onshore flows in your Class A?
I live in the high desert near Edwards AFB. I camp in the cool weather but charging and stuff is done at home in the heat. I do need to come up with something because the Iota shuts off at much over 100 so floating with it is a no go then. No interest in going that far with adding electronics to my chargers. My tweak gene only goes so far with this RVing stuff. :) I would rather tweak my computer! Besides my next project is solar and I have some things to do first to prep for that.
pianotuna
Nomad III
May 03, 2014
Hi Niner,

15.4 is the highest safe voltage.

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