Question for the Battery Guru's

[joesam]

The Battery Minder/maintainer I have installed (I installed the Marinco twist plug and receptacle last nite - it looks and works great); will trickle charge IF the batteries fall below their device's recommended float level (about 55.2v). Otherwise it just sits there waiting for a voltage drop below that - then pumps it back up. So its not quite "constant" just doggedly persistent in keeping battery voltage at an optimum level.

[55BigBlock]

Originally Posted by joesam

The Battery Minder/maintainer I have installed (I installed the Marinco twist plug and receptacle last nite - it looks and works great); will trickle charge IF the batteries fall below their device's recommended float level (about 55.2v). Otherwise it just sits there waiting for a voltage drop below that - then pumps it back up. So its not quite "constant" just doggedly persistent in keeping battery voltage at an optimum level.

Did you parallel the Marine receptacle with the existing charger receptacle or did you wire it direct to the pack?

[Stevegrmich]

. . . a working, plugged in OBC/Powerdrive charger combination IS a battery maintainer . . just saying . .

[Sergio]

From what I read using a trickle or constant charger with FLA batteries is not a good idea if they are left unattended. The reason is that they will slowly gas away leaving the plates exposed. Most of the gasing is caused by electrolysis once the cells are at full voltage, not by heat.
Maybe I am not understanding the voltage you posted correctly, but a 48v pack will never have 55.2v at rest, so it will always be charging after a few hours of rest.

[joesam]

Wired direct to pack, with a 15A fuse (recommended by the Minder folks). Mostly because I'm a neat freak, all of my accessory wires are connected using a second (top) nut (1/2" not 9/16" like original) and fused. That helps to "lock" the OEM nuts and makes it easy to monitor the condition and cleaning of the original cart connections below them. The receptacle is about 1" below the Powerdrive receptacle, so I don't ever goof-up and plug them both in.

[joesam]

Oops - told you I have brain fades - the 55.2v is the charge voltage, the float voltage is supposed to be about 52.2v. I agree that over a long period of time there will be gassing-off. But how long would that be if the batteries are properly filled? In my case, the cart will be sitting at about -10 degrees or lower. Gotta be less heat/gassing under those conditions, nothwithstanding electrolysis. My buddy has used one of these for his Piper 235 aircraft for years, and leaves it on for 3 months (sometimes more) with no apparent ill effects.

As to the Powerdrive charger - I agree, it is supposed to come on by itself. And my batteries (barely) lasted 11 years using just that over winter. But like Sergio, I was always wondering about a charger capable of 12-15Amps of energy being left unattended.

[55BigBlock]

Originally Posted by joesam

Wired direct to pack, with a 15A fuse (recommended by the Minder folks). Mostly because I'm a neat freak, all of my accessory wires are connected using a second (top) nut (1/2" not 9/16" like original) and fused. That helps to "lock" the OEM nuts and makes it easy to monitor the condition and cleaning of the original cart connections below them. The receptacle is about 1" below the Powerdrive receptacle, so I don't ever goof-up and plug them both in.

Maybe I am over thinking this but if maintainer is hooked to the pack as you described, is it still parallel to the existing circuit and the OBC? If so, how will the OBC react to a maintainer? Should the cart be placed in the tow position before the maintainer is plugged in? Will that isolate the pack from the OBC?

[Sergio]

I think 11 years out of a pack must put you in the top 2% on how to maintain batteries

[joesam]

OK - this is me just guessing - but if the big-rubber OEM plug is out - the OBC is completely-out-of-circuit as far as my logic dictates. Actually I used the battery minder "manually" for a week or two - but then went back to the Powerdrive I again because of the hassle of lifting the seat and connecting the posts. The Powerdrive worked normally for a week or two afterward, so I'm thinking my logic is correct.

Being a Regen I, my cart doesn't even have a tow switch - it uses a timed relay to default to "tow" after a few seconds. However, if I had one, I would definitely put the cart in tow for long term storage.

But hey guys...I don't sell these things and definitely would not feel comfortable recommending one to anybody that wasn't willing to take what I think is a very small "risk" on "unproven" technology. Plus, my batteries are ancient and due for replacement anyway. I should be so lucky to wake up next spring and find they still work for a 12th year! I was just letting folks know what I was trying for this winter.

[55BigBlock]

Originally Posted by joesam

OK - this is me just guessing - but if the big-rubber OEM plug is out - the OBC is completely-out-of-circuit as far as my logic dictates. Actually I used the battery minder "manually" for a week or two - but then went back to the Powerdrive I again because of the hassle of lifting the seat and connecting the posts. The Powerdrive worked normally for a week or two afterward, so I'm thinking my logic is correct.

Being a Regen I, my cart doesn't even have a tow switch - it uses a timed relay to default to "tow" after a few seconds. However, if I had one, I would definitely put the cart in tow for long term storage.

But hey guys...I don't sell these things and definitely would not feel comfortable recommending one to anybody that wasn't willing to take what I think is a very small "risk" on "unproven" technology. Plus, my batteries are ancient and due for replacement anyway. I should be so lucky to wake up next spring and find they still work for a 12th year! I was just letting folks know what I was trying for this winter.

As I said in an earlier post, I had been thinking about using some type of battery maintainer because of prolonged storage when I read your post. I don't think it is a matter of unproven technology, I just want to make sure all potential problems are considered before hooking something up. You know one of those 40db brain fades you referred to in post #8. Anyway, I appreciate your insight and help. I had no intention of offending or second guessing you. I just wanted to educate myself.