Correct Charge voltage on 72v accusense Charger BBB

[rockfordpi]

72v bad boy buggy (9 8v batts). When I test the battery voltage at various times during charge, I get anywhere from 89v to 93v. Is that normal?

Owner is complaining about run time and excessive water usage. Also only got 2.5 years out of batteries.

[bronsonj]

For Trojan batteries the Bulk charge is at 2.40vpc and finish charge at 2.55vpc for three hours according to:
https://www.trojanbattery.com/pdf/U....2011-12-13.pdf

An 8 volt battery has 4 cells. So you should be good up to 91.8v if those are Trojan batteries or another battery made by Trojan.

[rockfordpi]

Originally Posted by bronsonj

For Trojan batteries the Bulk charge is at 2.40vpc and finish charge at 2.55vpc for three hours according to:
https://www.trojanbattery.com/pdf/U....2011-12-13.pdf

An 8 volt battery has 4 cells. So you should be good up to 91.8v if those are Trojan batteries or another battery made by Trojan.

they are US Batteries, but I am guessing the should be close to same?

[JohnnieB]

The US Battery spec for the finish charge is 2.55VPC +/-0.05VPC and 2.60VPC times 36 is 93.6V for a 72V pack.

However, the DPI Accusense charger uses dV/dT and US battery specs a change in voltage rate of 0.004V/cell/hour, so the on-charge voltage immediately before the charge is terminated could be slightly over 100V.

Suggest you contact both US Battery and DPI for the most accurate information.

[rockfordpi]

Originally Posted by JohnnieB

The US Battery spec for the finish charge is 2.55VPC +/-0.05VPC and 2.60VPC times 36 is 93.6V for a 72V pack.

However, the DPI Accusense charger uses dV/dT and US battery specs a change in voltage rate of 0.004V/cell/hour, so the on-charge voltage immediately before the charge is terminated could be slightly over 100V.

Suggest you contact both US Battery and DPI for the most accurate information.

Thanks Johnnie, exactly what I needed. These batteries on 48v discharged in 28 minutes at 56 amps, so pretty sure batteries are bad. At least now I (think I) know I do not have a charger issue that was causing the early failure.

[JohnnieB]

Originally Posted by rockfordpi

Thanks Johnnie, exactly what I needed. These batteries on 48v discharged in 28 minutes at 56 amps, so pretty sure batteries are bad. At least now I (think I) know I do not have a charger issue that was causing the early failure.

Dumb question.
Is DPI set to US battery mode?

Also, which of the four USB 8V offerings are they? (155AH, 170AH, 183AH or 205AH)

Plus, cart batteries don't last as long in hotter climates

[rockfordpi]

Originally Posted by JohnnieB

Dumb question.
Is DPI set to US battery mode?

Also, which of the four USB 8V offerings are they? (155AH, 170AH, 183AH or 205AH)

Plus, cart batteries don't last as long in hotter climates

DPI is set to US Battery mode and voltage was dead on the number you gave me for finishing charge. I was concerned because User says they are just drinking water.

They are the 170 AH Battery, which seems small for 4wd BBB, however, they are Nine of them. I have seen BBB with 8 HD s volt, and have seen them with 6-12 volt, this is my first 9-8volt setup, and it appears to be factory setup.

Going to replace them with crown CR-165.