Upgraded to 48v, charging dilemna

[imaeyeguy]

Recently upgraded my EZGO TXT series cart from 36v to 48v. My new setup is 8x6V. All batteries are less than 3 months old. I am thinking of using the existing 36v charger for the original 6 batteries and using a marine charger (minn Kota, etc.) to charge the 2 new batteries in series separately. I’ve been reading about final phase cycle and not sure if the marine charger does something similar. Would this arrangement work out for the long term or am I going to find problems with reduced battery life with the 2 new 6V batteries charged separately?

[Sir Nuke]

Originally Posted by imaeyeguy

Recently upgraded my EZGO TXT series cart from 36v to 48v. My new setup is 8x6V. All batteries are less than 3 months old. I am thinking of using the existing 36v charger for the original 6 batteries and using a marine charger (minn Kota, etc.) to charge the 2 new batteries in series separately. I’ve been reading about final phase cycle and not sure if the marine charger does something similar. Would this arrangement work out for the long term or am I going to find problems with reduced battery life with the 2 new 6V batteries charged separately?

Do the right thing and buy a 48V DPI charger from ScottyB at cartsunlimited.net you pick/select the proper plug (TXT D plug #1 on the charger page) during the checkout phase.

[mutant]

duplicate post

[mutant]

Originally Posted by Sir Nuke

Do the right thing and buy a 48V DPI charger from ScottyB at cartsunlimited.net you pick/select the proper plug (TXT D plug #1 on the charger page) during the checkout phase.

X2 what he said-unless you dont value the investment you just made in your pack

[imaeyeguy]

Thanks for the replies. Of course the easiest way is to buy a 48v charger and problem solved. I was actually looking for technical advice as to why this would not work and not just an opinion. Why would a separate 12v charger not be adequate to maintain the two new batteries? Does it not use the correct charging protocol? Would it not bring the voltage back up to the same as the ezgo 36v charger? I searched extensively for prior post about this subject but was not successful in finding an answer. I apologize if this was addressed in another post before. If it was, please direct me to it.

[NCPW]

A 12V charger will not give a bulk charge to satisfactorily charge the 2 deep cell golf cart batteries. These aren't car batteries. Plus, using a separate charger will not balance the pack efficiently.

Jerry rigging the pack as your describing will ultimately decrease the life of the pack you just dropped a pretty coin on. Invest in a 48V DPI charger and you'll thank us later.

[NCPW]

Since you have new batteries I wanted to point you towards this sticky so you can follow the proper break-in for a new pack as well as battery maintenance.

http://www.buggiesgonewild.com/elect...batteries.html

[scottyb]

Hi Doc. To understand the differences you have know the charge requirements for the golf cart battery are unique. There are 3 basic charge phases.
These 3 phases of a golf cart battery charger are :
Bulk
Absorbtion
Float
Each phase operates at a different current to achieve the complete replenishment and equalization of each cell. This operation is called a charge algorithm. The charger has a specific cut off voltage, where the charge is complete & the DPI and other smart chargers go to and hold a float charge keeping the batteries at a slightly elevated state until you are ready to use.

A car or deep cycle charge on the other 2/6v will not do the same charge algorithm and the result maybe slightly diminished performance from these 2 batteries as the elements may permanently adhere to the plates without proper current and finish.

I have a friend who did what you propose for a season before getting the DPI. He has not mentioned any permanent damage effects.

For more information read my charge tutorial here > http://www.cartsunlimited.net/charging-tutorial.html
And see the smart chargers here > http://www.cartsunlimited.net/chargers-36-48v.html

[mutant]

Originally Posted by imaeyeguy

Thanks for the replies. Of course the easiest way is to buy a 48v charger and problem solved. I was actually looking for technical advice as to why this would not work and not just an opinion. Why would a separate 12v charger not be adequate to maintain the two new batteries? Does it not use the correct charging protocol? Would it not bring the voltage back up to the same as the ezgo 36v charger? I searched extensively for prior post about this subject but was not successful in finding an answer. I apologize if this was addressed in another post before. If it was, please direct me to it.

ah-i see your interest now...
i am no expert-just here reading and learning like you...

the death of ALL lead acid golf cart batteries is sulfation,a buildup on the lead plates that disables the from charging-discharging of the batteries as they are intended to do...
charging profiles are designed to minimize this process...the only reason not to do what you have proposed is it probably will damage your 2 batteries-and eventually the good batteries will be damaged also...this is why it is ill advisable to replace a bad battery in an old pack-the new battery will be damaged to the level of the old-poor performing batteries...

i have a G20 yamaha that had a battery dead short internally-the pack was 4 years old-so i replaced the bad battery and i have gotten 3 more years from the pack... it can be a bad idea to do what i did-but i got away with it for now-probably will be putting a new pack in soon but i got away with a sloppy fix...not something i recommend.

[JohnnieB]

Originally Posted by imaeyeguy

Recently upgraded my EZGO TXT series cart from 36v to 48v. My new setup is 8x6V. All batteries are less than 3 months old. I am thinking of using the existing 36v charger for the original 6 batteries and using a marine charger (minn Kota, etc.) to charge the 2 new batteries in series separately. I’ve been reading about final phase cycle and not sure if the marine charger does something similar. Would this arrangement work out for the long term or am I going to find problems with reduced battery life with the 2 new 6V batteries charged separately?

Charging a 48V pack with a 36V and a 12V charger can be done, but it takes some doing to keep the pack balanced and imbalances reduces the usable lifespan of the batteries.

The batteries are discharged in series, so the same amount of energy is removed for each battery. When charged in series, each battery has the same amount of energy returned to it. If the batteries are identical sextuplets, they will all be charged to the same SoC. Unfortunately, no two batteries are identical, so equalization charges are needed occasionally even when the batteries are charged in series.

If the existing 36V charger is a ferroresonant transformer type, the SoC of the batteries it charges won't be the same as the SoC of the batteries charged with a more modern charger design, so keeping the pack balanced is going to be a challenge.

Basically, you'll have to monitor the at-rest voltages of the individual batteries and give the low ones a boost charge as needed.

Getting a 48V charger make life a lot easier.