Back Up Charging System

I’m making a back up charging system for my GEM with two 36 volt automatic battery chargers. The GEMmechanic also mentioned using this system. I’ll take more pics of the system on the GEM in a week or two.
About me – I have had a variety of electric golf carts over the years to use at a club we belong to. I have converted my stock 36 volt EZGO to 48 volts which can easily do 22 mph with 4 people on board.
Anyway I thought I would mention the above so when you see me testing part of the system with a six pack of 6 volts you’ll know it’s for the ezgo.
In a previous post I mentioned that I installed 150ah batteries in the GEM. I believe I have to remove the Zivan charger and send it some where to be configured to charge these flooded 150ah batteries. I have read there is a switch for setting the Zivan to gel, agm or flooded but setting the Zivan for 150ah has to be done at a service center. Please correct me if I am wrong.

Look at the label on the front of the Zivan. If it has settings for C, D, E and F then you’ll see that F uses a higher finishing current than E. E is for the regular 150 AH flooded Trojan T1275 batteries and F is for the 8-volt battery option which are, I think, 180 AH. Using E may under-charge them and F over-charge them. On flooded cell batteries, the longer equalization charge will just boil off the water quicker - they’re pretty tough units.

My feeling is that, yes, you’ll need to have the charging profile reprogrammed to match your selection of batteries. But, if your Zivan has positions E and F programmed, you might be OK with one of them. I suggest running the pack down to 50% SOC and then charging on “E”. At the end of charging, check the specific gravity and if it’s fully charged, leave it alone. If under-charged, try position “F” and see what happens.

Thanks for the information Bob, I’ll give it a try.
I was also thinking of hooking up the back up system after the Zivan has completed it’s charge. If the Lestronics show it the batteries still need a charge then the Zivan needs to be adjusted or just sent to Zivan for reprogramming.

Just some follow up information.
After the Zivan shut off I hooked up my 36 volt chargers and they both ran for over 3 hours before they shut off. So the Zivan definitely has to go out for an update and a resetting for 150ah flooded batteries.
I am so glad I kept these extra chargers - I was going to sell them.