Power wise charging

[JohnnieB]

I'd use something more aggressive than spray cleaner on the Aux contact and radsok. Fine grit sandpaper, or a Scotch-Brite pad, or steel wool, followed by a rinse with spray contact cleaner or alcohol.

The thinner Red and Black wires. You might have a two-piece control board if you have a Powerwise model 28115 as pictured. The other end of the thin red wire attaches to the heatsink (clean that connection also) and the other end of the thin black wire attaches to the third wire in the output cable.

[scottyb]

46.5v divided by 18 cells = 2.59VPC
It's on the high side but it's not a number I would panic at.

[skipsmith521]

I purchased a new board for the charger...it was inexpensive. Waiting on it to ship. In the meantime will try the suggestions.

If the suggestions check out okay...could it be the controller board or did I waste the money?

Thx
Skip

Sent from my Nexus 6 using Tapatalk

[JohnnieB]

You only wasted the money if you don't need a control board, but at this point we don't know if you need a control board or not, so we can't know if the money was wasted.

[skipsmith521]

So here is an update...on my 36 volt charger.

I received the delivery on the new charger board faster than expected... I put in the board and it charges up to 46.1 and turns off.

Is that too high?

I have not tested the voltage at the board or cleaned the contacts just yet as suggested... If cutoff at 46.1 is okay, I will live with it.

Thanks for any feedback...

Sent from my Nexus 6 using Tapatalk

[JohnnieB]

No, 46.1V isn't too high.

The max voltage per cell listed on the attached Trojan recommended charge profile is from 2.45VPC to 2.79VPC. There are 18 cells in a 36V battery pack, so the recommended range is from 44.1v to 50.2V.

However, if that charger used to shut off at about 45.5V, it should still shut off at about 45.5V. Since two different control boards give you about the same results, the problem is in the battery sensing wires.

[skipsmith521]

The charger used to cut off at 45.5 and then would not turn off at all...it ran up to 46.6 and I just unplugged it myself.

I replaced the board and it cuts off at 46.1 now.

Still a little confused...should I still be looking for some other problem?

With the new board it is now turning off again...just not at 45.5.

Thx

Skip

Sent from my Nexus 6 using Tapatalk

[JohnnieB]

You are measuring the pack voltage with a DVM at the battery pack's main positive and negative terminals while the charger is measuring the pack voltage where the red and black wires connect to the control board. There are several feet of wire, several connections and at least one electrical contact between those two places of voltage measurement, so the two separate voltage measurements could be different when they ought to be the same.

Basically, the charger's control board is reading a voltage less than what the pack voltage is, so the charger chargers the battery pack to a higher voltage.

At the moment, the control board is probably seeing a voltage only about 1V less than true pack voltage, so it isn't much of an issue, but as time goes on, whatever the source of the excessive resistance is, will only get worse.

While the charger is pumping about 10A or more into the battery pack, measure the voltage at the battery pack's main terminals (lead posts) and at the red and black wires on the control board.

If those two readings are identical, nothing is wrong. If they aren't the same, you either fix it now or fix it later.

[skipsmith521]

I am following you now on seeing if there is a voltage difference...

I am not that knowledgeable on this... So I will ask a real basic question so I don't mess anything up...

So to check the voltage at the board...

1) take off charger cover
2) with charger cover off, plug AC power to charger...and plug charger into cart..wait for charger to start.
3) take my DVM and touch probe to the red and black wires...that are next to each other on the board?
4) that reading should match the pack charge?

Thx

Skip


Sent from my Nexus 6 using Tapatalk

[JohnnieB]

1.

2. Yes, but let the charger run for a little while before checking the voltages.
During the first few minutes of a charge cycle, the battery pack's on-charge voltage is going to be climbing rapidly and you want to wait until the climbing slows almost to a stop, so it won't change much between measurements at the two separate places.

3. Yes. The thin red and black wire ought to be next to each other, see attachment.

4. Yes