Disconnecting Battery of MEP-002A or MEP-003A While Running: Damage?

[CDR]

Sure, thanks for asking.

Any update

 

[R Racing]

I may need 1 soon myself !!

 

[Triple Jim]

Any update

Yes, I have one in my own 003A and a member here has a Beta unit in his 002A. We're getting quite a few hours on them between the two of us, running both with and without a battery connected, and they're working as planned.

I have parts for two more, and will put them together shortly. Parts have been ordered for ten after that. I don't want to break the rules and appear to be selling them in this thread, so I'll try to get a classified ad put together soon. If someone needs one before that, please send a PM.

 

[rustystud]

When you do decide to sell, I'll take two !

 

[CDR]

Yes, I have one in my own 003A and a member here has a Beta unit in his 002A. We're getting quite a few hours on them between the two of us, running both with and without a battery connected, and they're working as planned.

I have parts for two more, and will put them together shortly. Parts have been ordered for ten after that. I don't want to break the rules and appear to be selling them in this thread, so I'll try to get a classified ad put together soon. If someone needs one before that, please send a PM.

Please let us know in this tread when they are ready I don't think that will break any rules

 

[Triple Jim]

Yes, I do plan to do that. It should be only a few days.

 

[Triple Jim]

I thought I was done, but the temperature compensation came out a bit differently from my 12V version, so I'm going to change a couple things. I hope to have it ready by the end of the week.

 

[Triple Jim]

The 24VDC regulators are now available. I put a lot of time and effort into getting good temperature compensation, and am happy with the way it turned out. The set voltage now follows what lead-acid batteries want to see, with the charge voltage being higher in cold weather and lower in hot weather. At 25°C (77°F) it's set to 28.4 volts. As far as price, I did the best I could. I build them myself, and there's a fair amount of work in putting one together. The components are high quality and come from reputable industrial suppliers. As I mentioned above, I've been making a 12V version of this regulator for several years, and it's proven to be very reliable.

I updated my classified ad to include this regulator. I have parts to build them, so if anyone is interested please let me know. Thanks for the help and advice all of you gave me in this thread.

 

[Jimc]

those look fantastic jim!

 

[Isaac-1]

I agree great improvement over the original, I will be getting one

 

[CDR]

Great can't wait to get one

 

[dangier]

I did the beta testing on Triple Jim's dcvr on one of my 002A's. Needless to say, I am thoroughly impressed. The unit is configured to drop in with 3 nuts, 3 wire screw connections and two solder connections as stated. I had it installed in 15 minutes and running shortly thereafter. I ran the 002A a total of 28.5 hours. 9.75 hours were running without a battery. Just connect booster cables and start. Once running pull cables and everything stays on (insure positive batt connections insulated if no battery installed). I tested various 24 volt battery combinations (275 CCA to 750 CCA), in all states of charge. Each time battery circuit came up to 28.4 to 28.9 depending on ambient temperature. The monitor LED lights up when the regulator is starting to control. The LED status can be seen by opening the cover over the fuel shutoff while in operation. I will be equipping my most used units with this dcvr.
David

 

[steelypip]

Is this a shunt or series design? I'm guessing you went with series and MOSFET?

 

[Triple Jim]

No, it's a shunt design with a HexFET, which is a type of MOSFET. It's not always a good idea to go with a pass type regulator with a permanent magnet alternator, because when the circuit is opened, the stator can see voltages higher than it was designed for. If it's suddenly and repeatedly opened as with a PWM regulator, voltages could get very high.

 

[steelypip]

True. You basically trade off higher heat load on the stator for higher voltage in the windings. If your concern is overheating the stator then (see Ducati) then you want series, if your concern is the quality of the enamel on the windings, then you want shunt.

I was just thinking that, given how often the stock part dies, a series regulator would survive things like jump starting better.

 

[Triple Jim]

I don't expect any problems with this regulator. The HexFET is rated at 64 amps, with an on-state resistance of 0.016 ohm maximum, and the Schottky diodes in the rectifier section are rated at 30 amps. The fuse will blow long before the regulator is damaged.

Permanent magnet alternators don't necessarily get hotter with their output shorted. I haven't done a lot of testing with the one in the 002A and 003A, but the motor driven PM alternator from a motorcycle that I have on my test bench actually requires less power to drive and produces less heat when continuously shorted than it does when producing its rated output current.

 

[Speddmon]

AWESOME! I am ordering two right now!!!

 

[Speddmon]

Received my 2 regulators today in the mail. Man they look great!!!! As soon as I get some free time and the temp gets back above zero I'm going to try to get them put in.