A better alternator delete

[Daox]

Originally Posted by MetroMPG

Question: do the converters have LED's to indicate they're working? Would make monitoring / troubleshooting easier if one fails.

The dc-dc charging converters do not have an LED built into them. The AC power supplies do have an LED.

That being said, I might be able to put together something that would indicate when they are on. That would at least verify things are working as you said. I like that idea.

[MetroMPG]

Can you see the AC supply LED's -- viewports in the case?

[Daox]

You can probably see them through the side vents. However, just because the AC power supply is working doesn't mean the dc-dc is working. I'm much more concerned about them as they're cheap parts.

[Daox]

Before moving on, I decided to test the charging setup since its nearly completed already. I used alligator clips to connect the AC plug to the AC power supplies.






... and if we look closer, yay LEDs on the dc-dc converters. However, I'm not sure how visible those will be once the other panels are on haha.







And the AC power supplies LEDs are quite hidden (that little green bit is the LED and it is lit). I may be able to bend them so they're more viewable which would be a good idea.





I also threw it on my kill-a-watt and was actually pleasantly surprised. The cell voltages were all very close to 3.9V and the converters are set to put out 4A. There are 5 chargers going for each series string. Doing a little math brings that to 78W of actual charging going on. As we can see, this is pulling 100W (actually 98W at time of testing). This gives us a decent charging efficiency of 79.5%. That would mean roughly the AC power supply is about 90% efficient and the dc-dcs are also 90%. I was not expecting it to be quite that high. I was thinking more like 70% total efficiency.

[redneck]

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Looking good...

Maybe you could glue a piece of fiber optic to the led. Then drill a hole in the case, pull the fiber through and glue it in place in a position optimal for your viewing pleasure.



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[redneck]

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Examples of fiber optic cable being utilized early on by automotive makers.

Fiber Optic Lamp Monitors | AUTO BREVITY

It was just a thought.



>

[Daox]

As I let the unit charge up yesterday, I noticed another really nice perk that I hadn't really expected. For some reason, a lot of battery chargers really seem to use a decent amount of power on standby. I know my 48V lawn mower has 4 chargers, and it draws somewhere around 20W+ once the batteries are full. This seems pretty dumb to me. So, I was extremely happy to see that as the pack neared full the power consumption dropped from 100W slowly down down down and finally settled at 3W with all the indicators green on the dc-dc boards. It may have even gotten lower, but I unplugged it. I feel this is a great perk because this thing will be sitting at 'idle'. Its not a super fast charge at 3-4A (still haven't nailed it down yet). So, if you need 7 hours to charge, chances are you aren't going to unplug it before night and it will be sitting idle most of the night. You don't want it sucking up power all night long when its not really doing anything.

[Daox]

Originally Posted by redneck

.

Examples of fiber optic cable being utilized early on by automotive makers.

Fiber Optic Lamp Monitors | AUTO BREVITY

It was just a thought.



>

That would be a really cool idea!

I'm not sure I want to get that into it at this point. I'm debating just leaving it, or possibly adding a window with plexi-glass above the plugs so you can just look into it.

[MetroMPG]

Yay - LED's all around.


You really just need them for easy troubleshooting. Though fiber optics would be cool.

[Daox]

I've been doing some printing!

This is the top plate. Its printed fairly dense, and it is thicker than the other panels because it will have the handle attached to it. This meant it took 16 hours to print.







Next up we have the plug panel. This will be screwed into the end panel that has yet to be printed. Next to that is the switch mounting plate that I talked about a few posts ago.







And here we see how the switch mounts up to the top plate with the switch mount.





Next up are two little button extensions. Since the buttons on the low voltage cutoff are so low, I needed to print extensions so they would stick up and out of the top plate.





Now I can mount the low voltage cutoff circuit board up to the top plate.





And a view from the top. I'm very happy with how this is turning out.