2S-300mah packs weird parallel charge issue

[VFRLuke]

Hello

I have a 308 duo charger that I have been using for a little while and I have noticed something that I think might be odd.

I'm using one of these: http://www.hobbyking.com/hobbyking/store/__39652__micro_paraboard_jst_ph_e_flite_umx_6_x_2s _balance_board.html to charge 6 2S-300mah packs for my MCPX-BL and it's being REALLY slow balancing.

I think last night it took about 1.5 hours just to put a storage charge on them.

Here's where the weird starts. When I plug in the little paraboard without batteries plugged into it, the 308 duo reports Cell 1 as having a voltage of 1.470V. I'm going to go ahead and assume that this is due to the LED that's on the paraboard that lights up when you plug in a battery. Now I don't have any other cables or anything to try a method of charging without the paraboard, but it makes the IR readings not at all the same no matter which of my batteries I'm charging. I assume that this is causing balancing issues also. When I plug in a battery the cell voltages seem realistic.

I'm really tempted to just unsolder the LED from the paraboard and see what happens, but I figured I would ask and see if anyone else has had similar experiences.

I know I'm not the first person with an MXPX-BL that uses one of these little paraboards with a 308 or 4010 duo.

[RedOctobyr]

Strange. Does this happen on both channels of the charger?

I have a different fused parallel board, which I use with my 308Duo. It also has an LED. With no packs connected, it doesn't show any voltage for the first cell.

What do you see for cell voltages with just one pack connected, and with several of them?

I had a bad fused parallel board, it would sporadically show a high cell voltage for one cell. I think typically once multiple packs were attached. My suspicion is that one of the self-resetting fuses for the balance leads was bad, and was tripping, throwing things off. I got a replacement board, and it's been fine.

Granted, I'm charging larger 6S packs, but the LED hasn't done anything noticeable to me. Even for little packs, an LED draws so little current I'd be surprised if it could mess things up.

I'd go around with a single pack and connect it to each location, checking the displayed cell voltages each time. Then add more packs and check them again. Also while it's balancing, what do they show?

Something is clearly wrong, a Duo should be able to storage charge them very quickly, there is no reason it should take an hour and a half

[VFRLuke]

this little paraboard doesn't have any fuses. This problem happens on either channel. I have a bigger EC3 paraboard and it's fine.

I really don't think it's a problem with the charger, but with the paraboard itself.

next time I can get the mcpx out and run some batteries I'll collect some better data, either that or I'll just cut the LED off the board and see if it helps.

[RedOctobyr]

Indeed it does have fuses. They're self-resetting polyfuses, they're the chips on the board, towards the middle, in from the actual plugs. They just don't look like traditional fuses.

Also:

The circuit is protected with self-resetting fuses to prevent damage in the event of an accidental short of any battery whilst in parallel charge.

[VFRLuke]

Originally Posted by RedOctobyr

Indeed it does have fuses. They're self-resetting polyfuses, they're the chips on the board, towards the middle, in from the actual plugs. They just don't look like traditional fuses.
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I stand corrected now that I actually look at the board before I make assumptions.

after storage charging the 6 batteries in parallel, 3 of them are really balanced, and 3 of them are a little off. I'm separating them and seeing if one set of them charges a little faster than the others and am going to measure to see how balanced they are after a charge.

I might have a problem with one or more of my batteries, I just wanted to see if anyone else has the same symptoms with this little board.

[thanasi]

My paraboard for my 130 does the same thing
I'm also using a 308 duo

[VFRLuke]

Originally Posted by thanasi

My paraboard for my 130 does the same thing
I'm also using a 308 duo

good to know.

It also makes my IR readings way off balance as well.

I separated my batteries in groups of 3 so I was sure that I didn't have a bad battery in the mix.

first group of 3 ended up with IR 30.6, and 96.2
second group was IR 25.9, and 90.5

I know IR is not something that can be looked at when charging in groups, but being this far off balance indicated that something is askew. I still blame the LED. I think I'm going to cut it off or unsolder it and see what happens. Not like it's an expensive board or anything.

[VFRLuke]

for anyone interested, I unsoldered the LED and resistor that's in series with it and it didn't change a thing. I still show voltage as soon as I plug the board in without any batteries connected.

I suppose it is something with the fuses

then I went to charge a few packs, and when you plug them in everything seems normal, but upon the start of the charge cell 2 goes way high.

I guess I should have left it alone

[RedOctobyr]

I still think you have (and perhaps *had*, even before the LED surgery) a bad board.

Fuses, when not being activated, should basically be transparent to the user. My fully-fused board does not show cell voltages when no packs are attached.

But as mentioned before, a defective fused board *did* show a high voltage on one cell. Which was shown to be a false reading, when checking with another board:

Originally Posted by RedOctobyr

I had a bad fused parallel board, it would sporadically show a high cell voltage for one cell. I think typically once multiple packs were attached. My suspicion is that one of the self-resetting fuses for the balance leads was bad, and was tripping, throwing things off. I got a replacement board, and it's been fine.

[VFRLuke]

http://www.buddyrc.com/paraboard-par...3-reviews.html

found this too. There is a single review with 1 star that pretty much describes mine exactly. the reply said that they have designed a new board to take care of the problem.

I agree that the fuse really shouldn't matter, but because it's a self resetting fuse, there must be something that causes weird readings on the 308 charger.

[RedOctobyr]

FWIW, my board, which is this type (just different connectors):
http://www.buddyrc.com/paraboard-v3-xh-ec3.html

also has self-resetting fuses for the balance leads.

Now, it does have traditional big fuses for the main connectors. So that's definitely one difference from yours. Main current doesn't flow through the self-resetting fuses, on my board.

[VFRLuke]

Originally Posted by RedOctobyr

FWIW, my board, which is this type (just different connectors):
http://www.buddyrc.com/paraboard-v3-xh-ec3.html

also has self-resetting fuses for the balance leads.

Now, it does have traditional big fuses for the main connectors. So that's definitely one difference from yours. Main current doesn't flow through the self-resetting fuses, on my board.

I have that exact same board for charging my 3s-2200's and it works flawlessly.