2002 E825 Charging after sitting up 3months

Just bought my first cart, 2002 e825, so I’m a newbie here trying to consume as much info as possible.
I am getting the constant steady red blink with beep when plugging in to charge. The cart has not been charged for 3 months. When charging individually to bring them back to where they might take a charge, should they be disconnected from the series to do so?

Also, the battery disconnect is slightly corroded so I was looking to replace it, but cannot find the proper replacement. Is there a recommended replacement?

Thank you in advance, I’m sure I will have many more questions lol

Jimmy

Is this what you’re looking for?

https://www.nevaccessories.com/GEM-MASTER-DISCONNECT-SWITCH-BATTERY/productinfo/GEM-MDS/

That’s exactly it, but they are out of stock and don’t know if it will ever be restocked.
I’ve found other ”heavy duty” disconnects, but they are only rated for up to 48v.

As you deduced, a steady red blink sounds like your batteries may be under the charge threshold for your charger or perhaps your battery switch is in the off position?

What batteries are installed in your car and how old are they?

If you want to boost each battery you do not need to disconnect any cables, but it is better to shut off the batteries via the disconnect switch. Charge each one, then switch the battery disconnect back on and plug in the car charger to see if it will kick in. If not, you may have a bad battery in the pack.

If you don’t already have one, get a digital volt meter of reasonable quality for your tool bag. Make sure it will do at least 200vdc.

The lights and beeps only tell you part of the story.
You really get a better picture of what is going on if you use a meter to check the condition of your batteries.

If what you are looking at on the switch is surface corrosion is probably only external. If the switch still functions then just hit it with a light wire brush and some WD-40. Maybe even some paint if you really want to protect it(hopefully before you shot it with WD-40).

If the corrosion os on the terminals clean them as best as you can. Bright and tight is the rule.

Discussion-
I agree about the rating of some of these components. It is possible they might have been leftover from previous designs and somebody never upped the specs for the component or maybe the components today have been de-rated?

Thanks so much for taking the time!
My main concern with the disconnect is that it is does not feel like there is a defined on and off and it is also missing the little handle, so I’m currently using channel locks to turn it.

Do what they do on forklifts. Install an anderson disconnect plug.
Then you will have a positive disconnect and proper ratings.
Black for 80v.