New batteries

[JohnnieB]

Originally Posted by TreeBass

I have no idea about this one: check the On-Charge voltage on the battery sense wires going into the charger's control board.

The red and blue highlighted wires. Looks like you can measure between the heatsink and the terminal on the ammeter.

----------
Be sure to start that charger with the timer set to the "Start" position or it'll time out before it shuts off based on the pack's On-Charge voltage.

(The times tells you how long the batteries charged. Sort of worthless. )

--------
Also, what does the ammeter climb to when first first put on charge.
Should be 18A to 20A. If not, we need to check a couple things.

[TreeBass]

Ok, I'll check the charger. I always turn it to one, then let it go. It climbs to 18-20 then drops as time moves on. The timer knob has never moved, it just shuts off when charge is complete.

I changed the battery in the DVM, old battery shows 9.0

current readings after 12 hours or so:

1- 6.27
2- 6.29
3- 6.33
4- 6.30
5- 6.32
6- 6.30

total-37.8

[TreeBass]

Ok, do I need to measure those points on the charger while it's charging?

[JohnnieB]

Originally Posted by TreeBass

Ok, do I need to measure those points on the charger while it's charging?

Yes, while charging. Preferably when the ammeter is reading in the 18A range.

What I suspect is happening is that there is excessive resistance in the battery sense circuit, so the charger is sensing an On-Charge voltage that is higher than what is being applied to the battery pack.


Another way of checking is monitoring the pack voltage while watching the charger's ammeter. The amps should stay at max until the pack voltage climbs above about 41V. If it start dropping before that, there is too much resistance in the charge loop as well as the battery sensing circuit.

It would be a good idea to clean all the connections between the charge receptacle and main battery pack terminals as well as the male and female terminal in the receptacle and plug.

The charger turns off when the control board sees and On-Charge voltage in the 44V to 46V range and the batteries are charged in series, so any resistance in the charge loop will drop some voltage, so the voltage actually being applied to the batteries is less than it should be and they will be undercharged.

----------
The batteries are within 0.06V of each other, which is good.
However, the At-Rest voltage is at least 0.4V low, which is bad.

-----------

If cleaning the connections doesn't get the batteries charging fully, I'd jumper the relay and give the battery pack a 24 hour charge.

Don't worry about overcharging, the charger you have won't do it even if you left it on for a week.

Undercharging batteries kills them faster.

[TreeBass]

Originally Posted by JohnnieB

Yes, while charging. Preferably when the ammeter is reading in the 18A range.

Another way of checking is monitoring the pack voltage while watching the charger's ammeter. The amps should stay at max until the pack voltage climbs above about 41V. If it start dropping before that, there is too much resistance in the charge loop as well as the battery sensing circuit.

It would be a good idea to clean all the connections between the charge receptacle and main battery pack terminals as well as the male and female terminal in the receptacle and plug.

The charger turns off when the control board sees and On-Charge voltage in the 44V to 46V range and the batteries are charged in series, so any resistance in the charge loop will drop some voltage, so the voltage actually being applied to the batteries is less than it should be and they will be undercharged.

.

Ok, cleaned the snot out of the charge connectors, and fired it up. Only went to 15a on the charger, and started dropping pretty fast after hitting 44.x and now it's up to 45.0 and steady with the charger meter showing 1-2 amps

[TreeBass]

Originally Posted by JohnnieB

The red and blue highlighted wires. Looks like you can measure between the heatsink and the terminal on the ammeter.

----------
Be sure to start that charger with the timer set to the "Start" position or it'll time out before it shuts off based on the pack's On-Charge voltage.

(The times tells you how long the batteries charged. Sort of worthless. )

--------
Also, what does the ammeter climb to when first first put on charge.
Should be 18A to 20A. If not, we need to check a couple things.

Do we still need to do this ^^ check?

Originally Posted by JohnnieB

-----------
I'd jumper the relay and give the battery pack a 24 hour charge.

Don't worry about overcharging, the charger you have won't do it even if you left it on for a week.

And how would I do this?

I'm gonna owe you a lot of beer

[TreeBass]

Ok, ran it about 5 miles, pack voltage was 37.6

Connected the charger and let her go, went to around 20a ran to a pack voltage of 41.3 and dropped to 16a on the charger. It was at 42.5 below 15a and still charging.

According to Trojan, if during the charge the batteries rant at 7v, then I have a failed battery. Each battery showed 6.7 during the charge process.

I don't think that's the case in this instance, but instead a charger issue.

Thoughts? I'm clueless at this point and don't want to damage my new batteries

Thanks

[dahur]

I put in my new Trojans in June this year. After I charge them up, it takes about three days to get down to 38.2 if I don't use it.

[TreeBass]

Still charging, pack is at 45.5 and individual batteries are at 7.4-7.7

[JohnnieB]

Originally Posted by TreeBass

Still charging, pack is at 45.5 and individual batteries are at 7.4-7.7

I watched the NASCAR race and fell asleep in my recliner afterwards.

Appears that you are getting closer to getting your new batteries fully charged.

Are you running the charger with the relay by-passed, or did just cleaning up the connections get the charger staying on longer?