8878 rechargeable battery question

[Jurgen Krooshoop]

Yesterday I received my new 8878 Rechargeable Battery. In the (very limited) manual it says: "Fully charge when use the first time". I assumed this means fully charge before first use (manual isn't clear about that). And charging should take about 4 hours. My new & unused 8878 has been charging for over 20 hours now, but the red light is still flashing, indicating it's still charging.

Is this normal ? Or am I doing something wrong or is my 8878 bad ?

I'd appreciate to read your experiences, thanx.

Edited June 9, 2010 by Jurgen Krooshoop

[roamingstop]

Yesterday I received my new 8878 Rechargeable Battery. In the (very limited) manual it says: "Fulle charge when use the first time". I assumed this means fully charge before first use (manual isn't clear about that). And charging should take about 4 hours. My new & unused 8878 has been charging for over 20 hours now, but the red light is still flashing, indicating it's still charging.

Is this normal ? Or am I doing something wrong or is my 8878 bad ?

I'd appreciate to read your experiences, thanx.

First charge for me was about 6-8 hours.

[Milan]

My charging time is always 4 hours.

And it remains constantly alight when done.

[Jurgen Krooshoop]

My charging time is always 4 hours.

And it remains constantly alight when done.

I wish mine would do the same, but the red light keeps blinking.

[Milan]

Did you consider using battery until it is completely empty, then charging it again?

[Jurgen Krooshoop]

Did you consider using battery until it is completely empty, then charging it again?

Haven't done that yet, because it was a new battery and the manual says it has to be fully charged the first time. But I will propably try that next.

[Milan]

Ok, but mine battery was already at full, when I received it (new sealed)

So was the Sariel's battery, as he stated in his review.

I simply used the battery until it was empty, charge it until light stopped blinking, and repeat 5 or 6 times so far.

[Blakbird]

Haven't done that yet, because it was a new battery and the manual says it has to be fully charged the first time. But I will propably try that next.

You may as well go ahead and try to use it. Unlike Nickel-Cadmium batteries, Lithium-Polymer batteries have no charge memory so there is no issue with fully depleting them when they have not been fully charged. The lack of a full charge indication is puzzling, but of greater importance is whether or not there is something wrong with the cells preventing you from getting full capacity. I'd use it and make sure it lasts as long as it should. If it doesn't, then return it.

Another thing to do would be to put a voltage tester across it. Lithium cells are nominally 3.6V, so the 2 cell LEGO battery should be slightly greater than 7.2V when charged. If it is significantly less, you have a bad cell.

[Jurgen Krooshoop]

I just got home from work, and the red light was still blinking :-( It had been connected to the transformer for almost 30 hours....

You may as well go ahead and try to use it. Unlike Nickel-Cadmium batteries, Lithium-Polymer batteries have no charge memory so there is no issue with fully depleting them when they have not been fully charged. The lack of a full charge indication is puzzling, but of greater importance is whether or not there is something wrong with the cells preventing you from getting full capacity. I'd use it and make sure it lasts as long as it should. If it doesn't, then return it.

Another thing to do would be to put a voltage tester across it. Lithium cells are nominally 3.6V, so the 2 cell LEGO battery should be slightly greater than 7.2V when charged. If it is significantly less, you have a bad cell.

OK, so I guess it's safe to try and use it. So I did, and the battery performs well. But I don't know how long it should last, cause it's my first 8878. I did buy 2 rechargeable batteries, so I'm charging the second one now with the same (original) transformer. If it also takes long to charge, than maybe the transformer isn't what it should be.1

[DLuders]

That's what I think -- the Transformer may not be correct. Recall This EB Post when somebody noticed that there was confusion about the proper transformer. Is the one that you are using an 8887 10V DC Transformer, or something else? Maybe TLG sent you the wrong one....

[Jurgen Krooshoop]

That's what I think -- the Transformer may not be correct. Recall This EB Post when somebody noticed that there was confusion about the proper transformer. Is the one that you are using an 8887 10V DC Transformer, or something else? Maybe TLG sent you the wrong one....

The description on the transformer is exactly what is should be: 10v, 700 mA, I checked (3 times). So that shouldn't be the problem.

[DLuders]

By coincidence, I got a birthday gift today from my mom -- the same Power Functions 8878 Rechargable Battery and the 8887 10VDC transformer. I did not use it, but plugged it in to see how long it would take to go from "flashing" (charging) mode to "steady light" (charged) mode. It took a little over 2 hours using US 120V AC power.

After you discharge your battery and plug it in to recharge, if it still "blinks" for a day without going to the steady-light "charged" mode, I'd return it. The setup is too expensive to settle for a defective product.

[Jurgen Krooshoop]

By coincidence, I got a birthday gift today from my mom -- the same Power Functions 8878 Rechargable Battery and the 8887 10VDC transformer. I did not use it, but plugged it in to see how long it would take to go from "flashing" (charging) mode to "steady light" (charged) mode. It took a little over 2 hours using US 120V AC power.

After you discharge your battery and plug it in to recharge, if it still "blinks" for a day without going to the steady-light "charged" mode, I'd return it. The setup is too expensive to settle for a defective product.

That's what I'm gonna try next. I chose NOT to charge my second 8878 and use it right away, cause Milan's and Sariel's 8878's were already full when they received them. Both are working now. When they're empty, I'll recharge them both and see what happens then....

Thanx for the help sofar guys !!