sealed lead acid battery charger - mosfet equivalents

Thread Starter

Robononymous

Joined Sep 27, 2017
2
I have 3 identical 28v battery charges that have all been blown because they were wired incorrectly to 2 x 12v sealed lead acid batteries (in a 24v series connection). I suspect a MOSFET is blown, but I'm battling to find the parts.
The specific MOSFETS have the following printed on them:

N6D
KCH30A10

DO1145
W20NM60

The chargers have the following data spec:
Material number: FL-C40417
Input Scope: AC 220V
Input Power: <\ 80 Watts
Output Voltage rated: DC 24V
Equal charging voltage:29.8+-0.2V
Floating Charge Voltage: 27.8+-27.8+=0.2V
Max Output Current: 6.5A
Overall unit productiveness: 80%-90%
 

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phranzdan

Joined Aug 4, 2017
40
I have 3 identical 28v battery charges that have all been blown because they were wired incorrectly to 2 x 12v sealed lead acid batteries (in a 24v series connection). I suspect a MOSFET is blown, but I'm battling to find the parts.
The specific MOSFETS have the following printed on them:

N6D
KCH30A10

DO1145
W20NM60

Hi: The KCH30A10 is a dual diode with common cathode rated at 100 volts and 30 amps. The W20NM60 is a fdmesh power Mosfet with a fast body diode. The fet is rated at 600 volts and 20 amps. You may need to look for some alternative parts. The data was found on Alldata. Hope this helps.

The chargers have the following data spec:
Material number: FL-C40417
Input Scope: AC 220V
Input Power: <\ 80 Watts
Output Voltage rated: DC 24V
Equal charging voltage:29.8+-0.2V
Floating Charge Voltage: 27.8+-27.8+=0.2V
Max Output Current: 6.5A
Overall unit productiveness: 80%-90%
 

Thread Starter

Robononymous

Joined Sep 27, 2017
2
Thank you guys.
When connecting the batteries we got the polarity wrong, as i mentioned which is why the charger blew. I cant think that anything else was blown so to test the mosfets I measured diode junction with the multimeter leads situated one way and then flipped the leads of the multimeter to the reverse position, to switch polarity. i read somewhere that one side of the diode junction should read a very high resistance, above 1MΩ of resistance (the anode-to-cathode side) and the other side should read a much lower resistance, maybe of a few hundred thousand ohms (the cathode-to-anode side). is this how you'd test them? is anything else that was likely to have been damaged besides these transistors?
 

Dodgydave

Joined Jun 22, 2012
8,688
To test diodes or transistors,put your dvm on Diode test, usually picture of a Diode on the range knob, and looking for 0.2 to 0.7V depending if its a schokley type or ordinary silicon, this is the same for fet transistors D/S.

Your blown devices are a Dual diode and N-fet.
 

ian field

Joined Oct 27, 2012
6,539
To test diodes or transistors,put your dvm on Diode test, usually picture of a Diode on the range knob, and looking for 0.2 to 0.7V depending if its a schokley type or ordinary silicon, this is the same for fet transistors D/S.

Your blown devices are a Dual diode and N-fet.
The TS should beware that Shottky barrier rectifiers can show significant leakage and not be faulty.

The 20A 600V MOSFET is in a flyback SMPSU - the switching speed is probably important when selecting a substitute.
 
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