Giant Suede Battery Charging Problem

[rickhoover]

Hello all! I'm a noob, and this is my first post. Has anybody had experience with the Tenergy 3A 36V Ni-Mh charger. It receives 2.5 out of 5 stars from the selling site all-battery.com and can be purchased cheaper at Amazon.com ...I bought a used Giant Suede with its 2 original batteries and the charger. It rode fine during the test ride, but when I got it home the charger started its blinking lights ordeal indicating it was charging correctly, and thus not charging. I thought the batteries were bad. So I soldered up a new series of D-cells, soldered the old terminals up to them with [including the two resistors and the temp sensor (not sure if either of those are good, and if they may in fact be part of the problem)], but the charger still indicates with its blinking light that there is a problem charging. Any help or advice is appreciated...TIA!

[ambroseliao]

I'm confused by your statement, "the charger started its blinking lights ordeal indicating it was charging correctly, and thus not charging."

Does it charge or not? Is this true for both batteries? What exactly happens? Do you have a voltmeter to test the batteries and the charger?

Ambrose

[rickhoover]

I'm confused by your statement, "the charger started its blinking lights ordeal indicating it was charging correctly, and thus not charging."

Does it charge or not? Is this true for both batteries? What exactly happens? Do you have a voltmeter to test the batteries and the charger?

Ambrose

Both original batteries don't charge (including the new battery I made, thus all 3 batteries don't charge). There is a little reset button on the charger that I have to press in order for it to kick start its cooling fan, and it will only run with the fan while trying to charge one of the batteries. The other battery it doesn't respond at all to. Nevertheless, the light that blinks and is supposed to remain steady after 5 seconds never quits blinking; thus indicating an error. It says to refer to the [owner's] manual if blinking exceeds 5 seconds. The bike didn't come w/ a manual, but I was able to get a pdf version e-mailed to me from the friendly folks at Giant Bicycles. The manual says to bring the bike into your dealer, HA! I have tested the batteries and they all have a charge of approximately 37-38V, but I read on another forum that they need to bee at least over 39V preferable 40-41to get the bikes SOC indicator to give a healthy read out and for the bike to function properly. I haven't tested the chargers volts, as I'm unsure how to. I can't help but wonder if there isn't a problem w/ the little resistors, or temp sensor, hooked up to the battery, and thus causing the error w/ the charger. I disconnected them from the pack I made (soldered) after initially connecting them to it, to see if that might appease the charger, but still no dice. Again TIA for any help.

[dnmun]

how many cells in series? can you measure the individual cell voltages when it is on the charger? 1.41V is fully charged, voltage drops after that and the cells heat up instead of taking charge.

[rickhoover]

30 D Cells all measuring around 1.2V dormant, but I haven't tested them while on charge (not even sure if it is charging, but this will be helpful to see if it is). I want to believe the charger thinks the cells are overheating, and thus doesn't put out a charge. Or it could be that the charger is problematic.

[ambroseliao]

Not knowing anything else about your setup, I would suspect the charger since your batteries are measuring fine.

[Hillhater]

do you have a MMeter to check the charger output & connections ?
does the charger have a 3 pin connector for the battery ?
I would suspect a bad connection in the charge lead/charger.

[amberwolf]

I have an old pack from one of those bikes; it had a thermistor connection problem at one point, and that would (should) cause a charger to not start a charge. There are also two thermal fuses in series with the charging wires, and either of those blowing means it will read correctly at the output pins but not at the charging port, if those are different.

Measure the thermistor pin on the charging port to battery negative, and see if you get a few k-ohms resistance. If it's way less than that or way more, you probably have a connection failure in the thermistor.

If it all reads correctly, then there is probably a connection problem in the charger itself, from it's board to the end of the output cable.

[rickhoover]

Just checked inside the connector for the charger to the battery and the 3 prong on the charger end has had it's skinny white wire come undone inside the connector. The heavier gauge red and black are fine. I'll report back after soldering the white wire back to the connector to see if that resolves my issue. I hope it does. Thank you all for such great feedback!

[rkosiorek]

if it is now working, you will have to add a 10K NTC thermistor to your new pack of "D" cells before it will charge properly.

rick

[rickhoover]

How I wish I would have found that little white wire disconnected sooner!

[ambroseliao]

So it's working now?

[rickhoover]

been charging for 'bout an hour now... sure wish I would haven't bought those 30 D cells now, except they are 10Ah instead of the stock 8Ah... sure am glad I didn't buy the other charger

[amberwolf]

Depending on who made those "10Ah" cells, they probably don't hold anywhere near that amount. It's quite possible that the aged and possibly decrepit cells in the Giant packs still have more capacity than the brand new ones. I just see so many NiMH cells that can't even provide their rated capacity when used as low-power LED flashlight batteries (at 10-50mA currents), much less anything an ebike will put them thru.

Do you have a wattmeter you can test them with? I'm very curious as to what they actually can do--capacity, voltage sag under load, temperature after loaded operation, etc., as well as manufacturer.

[rickhoover]

Yeah, I wish I had a wattmeter to determine the batteries condition. The one 8Ah sadly only lasted a range of about 4-5 miles (haven't hooked an odometer up yet). I am going to try and charge the 10Ah pack now to see how it does with hope that it might have been a necessary purchase after all. I do know the new battery pack only weighs 6lb 12oz, while the old 11lb 1oz -- not sure yet if that should be a cause for joy or serious concern; time will tell.

[amberwolf]

If the packs haven't been used in a while, a few charge discharge cycles may be needed to bring them back to normal.

[rickhoover]

Well the new pack charged in about 40 minutes, opposed to the nearly 3 hrs of the old pack. We'll see how she does on a ride.

[dnmun]

i doubt if the pack is balanced, so be careful riding it to exhaustion since you may end up reversing a buncha cells. too bad you can't measure them beforehand.

[docnjoj]

For that new NiMh pack you really need to charge it at a low rate, say C/10 or about one amp or less for a day or two. Half an amp is even better.If the cells are any good they do self balance and then you can charge it with the regular charger. Otherwise, as state by others they will probably be reversed at the end of the miles you travel and damaged.
otherDoc

[rickhoover]

The only charger I have is the Giant's 2 Amp, and I certainly don't want to damage the new pack. Any advice? Don't ride it 'til full discharge?

[dnmun]

you don't seem to understand what we were talking about. imagine that you charge the pack up, adding about 4Ah until the charger detects endpoint. so imagine you have 29 cells that are full and measure 1.4V each because they are full and one cell is at 1.1V and is only holding about 4Ah of charge that you just stored in it.

then you run the battery down to LVC on the controller using about 6Ah of charge.

30.5V is the total voltage. 29 of the cells are measuring 1.05V and have about 4Ah of capacity left 1.05x29=30.4V.

the cell that had the 4Ah stored now has been reversed while large amounts of current flowed through it. after that, it will not take charge, and you no longer have a functional battery. that may be what has already happened to the first pack you said was dead, just no way to know without ever measuring.

[rickhoover]

About a week ago 2 of the cells on the pack I made measured almost nil after I accidentally shorted them (they sparked). I thought they were ruined but later the pack measured about 37V and the cells each measured around 1.2V.

[rickhoover]

I haven't ridden on the new pack yet; just put the 40minute 2Amp charge on it. I charged up the old pack and it took less than an hour this time. i will only ride on the old pack until I know that I won't be hurting the new one.

[dnmun]

ok, with nicad the voltage is related to charge stored so if they are all at the same voltage, then they are as close to balanced as you can get them. but some assume that 36V over 30 cells means that each is at 1.2V, which may not always be the case, but the nicads will tend to balance themselves with multiple charging cycles because the first to fill with charge will just get hot as the others catch up.

[rickhoover]

These are NiMH, does that matter?