Trojan batteries

[JohnnieB]

No need to disconnect them. But don't do it while the 36V charger is also connected.

I don't know which batteries are tapped for 12V, but it should be one of the three sets shown in attached drawing.

Let the pair charge until the on-charge voltage reaches 14.8V.

[Rangerdaniel]

Thanks a lot for all the help.
I will connect a charger to them later (while the others are being charged). Good advice. I didnt know I could do that.

I know which 2 are hooked up to the lights so it will be very easy.

Now regarding the electrolyte levels,,, I read your link and believe mine to be a tad bit high. I didnt realize the 1/8" trick. I have them barely touching the bottom of the plastic (as I was told, and always with distilled water).

Will that make a big difference?

[JohnnieB]

Originally Posted by Rangerdaniel

Thanks a lot for all the help.
I will connect a charger to them later (while the others are being charged). Good advice. I didnt know I could do that.

I know which 2 are hooked up to the lights so it will be very easy.

Now regarding the electrolyte levels,,, I read your link and believe mine to be a tad bit high. I didnt realize the 1/8" trick. I have them barely touching the bottom of the plastic (as I was told, and always with distilled water).

Will that make a big difference?

Do Not connect the 12V charger while the 36V charger is connected.

It might destroy one or both chargers!!!!!!!!!!!!!!!!!

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Over filling causes the cells to overflow while charging and the liquid acid mixture gets on the battery tops.

If overfilled repeatedly, the acid concentration in the electrolyte is reduced, because only water is replaced, but other than that, it is just a mess to clean up.

Each cell in a T-105 holds about a gallon of electrolyte, so it will take a lot of spillage to adversely effect the acid concentration.

[Rangerdaniel]

Oops!!!! Thanks.
They are 605, sorry
Thank u

[JohnnieB]

That does change things a bit, but the voltages will still be the same.

Run-time will be about 10% less and they won't last quite as long before needing to be replaced, but with proper care they should last at least 3 years or more.

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The volume of electrolyte will be about the same. The boxes are the same size, the number of plates is different.

[Rangerdaniel]

Ok, I plugged a 12 volt charger up to the 2 batteries where the lights are plugged up.

After only a little time the Scottyb's digital meter read 38.1. After charging it for about 8 hours the voltage never got about 14.3 (that I saw) on the 12V charger.

After unhooking the 12V charger I hooked it up to the cart charger and it only charged for about 1 minute. Now it is reading 38.0!!! Very good to see. Not really sure where to go from here? After driving it a bit should i hook the 12V charger up again? or just the cart charger?

Advice going forward?

[scottyb]

Just a general note here for everybody the T605 has a reduced capacity when compared to the T105 and I have in the past seen where this reduced capacity has led to over taxing of the battery pack under what we consider normal use. The T605 is not the OEM battery. This heavy taxing has reduced the useful life of these packs.

Charge em up again and again and keep em charged up

[JohnnieB]

Originally Posted by Rangerdaniel

Ok, I plugged a 12 volt charger up to the 2 batteries where the lights are plugged up.

After only a little time the Scottyb's digital meter read 38.1. After charging it for about 8 hours the voltage never got about 14.3 (that I saw) on the 12V charger.

After unhooking the 12V charger I hooked it up to the cart charger and it only charged for about 1 minute. Now it is reading 38.0!!! Very good to see. Not really sure where to go from here? After driving it a bit should i hook the 12V charger up again? or just the cart charger?

Advice going forward?

I'm speculating, but you might have some charger/charging issues.
The 36V charger only staying on for 1 minute is waving a red flag at me.

What 36V charger do you have?
What is the pack voltage immediate before or after the charger shuts off? (It should be in the 44-46 volt range)

Unwanted resistance in the cables the charging current flows will make a good charger see an erroneously high On-Charge voltage and the charger will shut off prematurely, not full charging otherwise good batteries and the good batteries will soon become bad when they are not being fully charged.

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Measuring battery voltage is a bit tricky because there are three sets of conditions.
The On-Charge voltage is much high than the At-Rest voltage and then there is the surface charge voltage that is in between those two.

The voltages listed on State of Charge vs Voltage charts are At-Rest voltages, meaning that the batteries have neither been charged or discharged (rested) for approximately 12 hours after the charger turns off automatically.

The On-Charge voltage is whatever the pack voltage is when the charger is first turned on up to the 44V-46V range (for a 36V pack - Higher for higher voltage battery packs - Roughly 7.5V per 6V battery)

When a battery is charged, the Sulfuric Acid concentration (aka Specific Gravity) of the electrolyte in intimate contact with the plates is higher than it is in the electrolyte further away from the plates. This is called a surface charge and it causes a higher voltage at the the battery terminal and reflects a State of Charge that is higher than the amount of energy that is actually stored in the battery.

To get an accurate SoC estimate based on battery voltage, the surface charge must be depleted. It typically takes about 12 hours for the uneven acid concentrations in the electrolyte to even out after being charged.

The reverse of surface charge occurs when batteries are discharged, so the batteries have to rest a bit before measuring the voltage after they've been used to get an accurate voltage for SoC. How long of a rest needed depends on how hard the were used, but 10-15 minutes will usually suffice.

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As for using a 12V charger.
The goal is to have the At-Rest voltage of all six batteries withing 0.10V (or less) of each other. (My old set were within 0.04 and my new set are within 0.02)

Measure the At-Rest voltage of the individual batteries, pair up the ones with the closest voltages and charge the lower pairs up with the 12V charger until they have the same At-Rest voltage as the highest pair. (If you have a 6V charger, you can do this singly instead of in pairs and won't have to shuffle the batteries in the pack)

Once all six are within 0.1V of each other, use the 36V charger and charge the living daylights out of them.