Upgraded to 48v, charging dilemna

[imaeyeguy]

Thanks to all for the replies.

Sounds like 48V charger may be in my future for ease of use as well as peace of mind. I am curious though if anyone has done some testing to see if a marine deep cycle charger (not automotive) like those used in bass boats that are designed to maintain trolling motor batteries would perform just as well on a 2x6v high amp hour battery system. The reason I'm interested is because I have one sitting in the garage and it would be a path of least resistance just to hook it up and run with it. I know that these onboard chargers are designed to maintain those batteries over extended times between uses as well as prevent sulfation. Since most boaters are as protective of their gear as the buggie world, they seem to be content as long as the charger is a good one.

I think I will conduct some tests to determine if it's feasible. I use my cart almost daily and will run some tests for a month of two to see if there are differences. Would measuring only voltage be sufficient or some other more precise measurement be recommended? If all batteries are measuring the same voltage over time, would that imply that they are all properly charged?

[mutant]

DPI does that for you as well...

[EZHO]

Originally Posted by imaeyeguy

Thanks to all for the replies.

Sounds like 48V charger may be in my future
.
The reason I'm interested is because I have one sitting in the garage and it would be a path of least resistance .

Especially with the holiday expensive's right now , i hear ya
.
JonnieB / Scottyb /Anyone ?...so if he needs to use the two charger method long term or just for now , is it a good idea to switch the two on the marine charger around to different two batteries, once a month / once a week / every charge cycle , or the benefit would not even be worth it ?

also asking for my own knowledge . (keeping a balanced pack)

[gornoman]

I ran the two charger routine for over a year when I converted my cart to 48v without any issues. As soon as I spotted a used 48v charger in the for sale section of the forum I grabbed it. Sold my old 36v charger for close to what I paid for the used 48v unit. The 12v charger I used was capable of 10 amp output, which worked well. I don’t know the capability of the OP’s 12v Charger so I cant comment on its suitability for the task.

[JohnnieB]

Originally Posted by imaeyeguy

Thanks to all for the replies.

Sounds like 48V charger may be in my future for ease of use as well as peace of mind. I am curious though if anyone has done some testing to see if a marine deep cycle charger (not automotive) like those used in bass boats that are designed to maintain trolling motor batteries would perform just as well on a 2x6v high amp hour battery system. The reason I'm interested is because I have one sitting in the garage and it would be a path of least resistance just to hook it up and run with it. I know that these onboard chargers are designed to maintain those batteries over extended times between uses as well as prevent sulfation. Since most boaters are as protective of their gear as the buggie world, they seem to be content as long as the charger is a good one.

I think I will conduct some tests to determine if it's feasible. I use my cart almost daily and will run some tests for a month of two to see if there are differences. Would measuring only voltage be sufficient or some other more precise measurement be recommended? If all batteries are measuring the same voltage over time, would that imply that they are all properly charged?

Monitoring the SG (Specific Gravity) of the electrolyte in the cells would be better, but At-Rest voltage closely tracks SG and is much easier to measure.

At-Rest means the batteries have been resting (no charge or discharge) for ate least 12 hours. If the marine charger has a float or trickle charge after the regular cycle ends, it will have to be disconnected at about the same time the 36V charger shuts off.

What are the Make & Model of the 36V and the 12V chargers?

[JohnnieB]

Originally Posted by EZHO

Especially with the holiday expensive's right now , i hear ya
.
JonnieB / Scottyb /Anyone ?...so if he needs to use the two charger method long term or just for now , is it a good idea to switch the two on the marine charger around to different two batteries, once a month / once a week / every charge cycle , or the benefit would not even be worth it ?

also asking for my own knowledge . (keeping a balanced pack)

The trick is to keep all the batteries at the same SoC. If the two being charged with the marine charger are not being charged to the same level as the other six, swapping them with two from the ones being charged by the 36V charger would probably be a bad idea.

[handtools]

So if I understand this correctly, wouldn't you have to disconnect the battery cables and reconnect them to a 36v configuration to charge 6 of them with the 36v charger then when they are charged and the other two are charged in series with a 12v charger reconnect the cables to 48v for cart operation? Seems like a pain in the a.. to me! Sell the 36v charger and get a DPI!

[imaeyeguy]

Originally Posted by JohnnieB

Monitoring the SG (Specific Gravity) of the electrolyte in the cells would be better, but At-Rest voltage closely tracks SG and is much easier to measure.

At-Rest means the batteries have been resting (no charge or discharge) for ate least 12 hours. If the marine charger has a float or trickle charge after the regular cycle ends, it will have to be disconnected at about the same time the 36V charger shuts off.

What are the Make & Model of the 36V and the 12V chargers?

The 36V Charger is power wise model G4. The 12V charger is a ProMariner ProSport 12, 12 AMP Dual bank marine battery charger.

[imaeyeguy]

Originally Posted by handtools

So if I understand this correctly, wouldn't you have to disconnect the battery cables and reconnect them to a 36v configuration to charge 6 of them with the 36v charger then when they are charged and the other two are charged in series with a 12v charger reconnect the cables to 48v for cart operation? Seems like a pain in the a.. to me! Sell the 36v charger and get a DPI!

No, not that complicated. The 8 batteries are connected in series to create the 48 volts. The 36V Charger is connected to Positive end of battery 1 and at the negative end of the 6th battery. The 12V Charger is connected to the Positive end of battery 7 and negative end of battery 8. Once set up, there is no further need to disconnect or reconnect.

[cgtech]

I wouldn't even consider putting my $$$.$$ pack at risk any longer than necessary. For a few weeks 'till I get a proper 48v charger, sure. As a "long term plan", absolutely not.