2.7 volts on a 36 volt pack

[azTony]

I have a cart that has never had low water but the voltage is very low on the 36 volt pack at only 2.7 volts. The cart is at a home that is a snow bird home and the tenants are unable to come to the home and asked me to check. The tag on the cart says

E403 Manufacture code
1603508 Serial No.

The batteries are

FVP Volt Edge
V15I4AJ code

They have a Power Wise charger model 28115 G04

If I understand correctly when the voltage is too low these chargers do not detect voltage and will not start charging. Is there a way to bypass that and get the charger to start working and charge the low pack?

Thanks for your help

[JohnnieB]

They have a 2003 TXT-PDS.

Open the charger and bypass the relay on the control board. Then it will power up whenever it is plugged into an AC outlet whether it is plugged into cart or not.

Picture is for a PW-II, but the it is done the same.

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I have my doubts if those batteries will recover if the total pack voltage is only 2.7V.

[Golferdave]

Check water level too

[azTony]

Plenty of water

Thanks for the reply Johnnie B!! Will the charger shut off when fully charged with the jumper on it? If I understand it correctly, bypassing the relay simply allows it to charge without first detecting voltage (what's the min voltage it checks for?) but the rest of the circuit board continues to work properly. Correct me if I am wrong please.

[rib33024]

No it will not turn off with the relay bypassed. The 36 volt pack will get to 45 - 47 volts when the pack is charged. Sounds like time for a new Battery pack. Don't forget about it charging

[JohnnieB]

Originally Posted by azTony

Plenty of water

Thanks for the reply Johnnie B!! Will the charger shut off when fully charged with the jumper on it? If I understand it correctly, bypassing the relay simply allows it to charge without first detecting voltage (what's the min voltage it checks for?) but the rest of the circuit board continues to work properly. Correct me if I am wrong please.

As Rib said, it won't shutoff.

The control board is a semi-smart switch that turns the charger on if the pack voltage is above about 28V and shuts the charger off when the on-charge voltage reaches about 45V, or shuts it off if it doesn't reach about 45V within about 16 hours, but all it actually does is energize or de-energize the relay that you bypass and with that relay bypassed, you have a totally manual charger.

[azTony]

Do you know the time involved to fully charge that pack so I have an idea when to go and shut it off?

[JohnnieB]

Originally Posted by azTony

Do you know the time involved to fully charge that pack so I have an idea when to go and shut it off?

May be 20 hours or more, if ever.

Because the ferroresonant transformer and capacitor arrangement of a PW-28115 starts reducing the output current when the on-charge voltage approaches 42V and tapers off to about 7A or less as it climbs towards 45V, That type charge can be left on a healthy 36V battery pack for a day or more.

However, it is going to pump out about 20A until the on-charge voltage climbs above about 42V and I have no idea how long that will take, or if they will ever reach 42V.

The batteries are completely dead, so if they are model FVPGC2-105WNG, they have a 225AH rating and if they are recoverable, it will take about 10 hours to reach 42V (90% of full charge) at a 20A charge rate. Until then there will be 20A flowing through them and they probably will get mighty hot. I don't know if anything will get hot enough to start a fire, but I'd charge them outside and not close to anything combustible.

Personally, I'd babysit them about two hours at a time on charge to see if they would take a charge at all.

[Golferdave]

If they take a charge, may take enough to to turn on the charger
In an hour or so
Take the jumper off & plug it back in

Left on / too long will dry them out fast

Get an AC timer,
https://www.amazon.com/Intermatic-FD.../dp/B003A1VJYM

[rib33024]

Well it's been 4 days they should be charged