12v acc batt plus voltage reducer

[sigfla45]

Is there any way or advantage to wiring a 48/12v reducer and a 12v accessory battery? I was thinking of something that would charge off the main pack while adding some additional capacity. When the cart is stored I envisioned a 12v trickle charger on the accessory battery and/or having the main charger feed it through the reducer.

Silly question but I have done similar things with my boat and isolating the 12v accessory battery.

[cgtech]

Never seen a converter for carts that's rated to charge a battery. And theres no technical advantage at all unless you have some very power hungry devices that a converter alone couldnt handle (like a winch, or stereo amps).

[sigfla45]

Originally Posted by cgtech

Never seen a converter for carts that's rated to charge a battery. And theres no technical advantage at all unless you have some very power hungry devices that a converter alone couldnt handle (like a winch, or stereo amps).

So then lets assume I install a winch. If I use the voltage reducer to power my buss bar (with all accessories wired to it) and keep my 12v wired to it as well. I shouldn't be pushing anything but 12v to all the accessories with the extra capacity of the 12v battery to add capacity for the winch. If I hook up my 48v charger I wouldn't be feeding anything into the reducer that it wasn't already made to handle and in any care it would only output 12v back into the buss bar anyway so a battery wired in parallel with it would only stay at 12v. I would just have to charge my 12v separately as I am doing now anyway. The only issue being the capacity of the larger bank vs the smaller 12v. Any electronics gurus know if that would cause an issue?

[sigfla45]

Actually now that I think about it the 12v charger will feed into the 48v pack. Plus my 12v is agm and the cart are flooded. Not worth the trouble I think. I am rewiring my stereo and accessories away from the 12v and hate to lose it when it works. I guess I’ll just deal with having an extra battery in the garage. I hate wasting stuff

[sigfla45]

Well I am back to contemplating this. If I install a quick connect between the battery and the buss bar I can just unplug it and use it to hook up to the 12v accessory charger. That would solve the issue of any possible back feed into the 48V pack. I would still be mixing 48v flooded batteries via the voltage reducer and the 12v AGM battery so I don't know if that would hurt anything though. I dunno I may end up getting a larger 12v and install it in the bagwell and avoid the voltage reducer entirely. I suppose I am just anxious about reducing my overall range by drawing off the main pack.

[JohnnieB]

The 12V battery won't back-feed to the 48V battery pack through the 48V to 12V converter. It's a one way street electrically.

However, the converter's output may be less than the at-rest voltage of a fully charged 12V AGM battery, which is 12.84V for Trojan brand.

Also, the absorption charge voltage for a 12V AGM is 14.4V and float is 13.5V, both of which is likely lower the the output voltage of the converter.

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A 16V Super-Capacitor could be used in place of the 12V AGM battery, eliminating the charging voltage issues.

[sigfla45]

I have moved away form the idea of charging off the main pack for the 12v agm. I would just use my trickle charger and unplug it from the buss bar to charge. There should be no direct connection of any kind during charging of the main pack or the AGM. The 12V AGM would simply act like a big capacitor like they use on car stereos supplementing the voltage converters input into the buss bar that all the accessories are hooked to. I have gone back and forth but I can't think of any issue why this would be a problem.

Originally Posted by JohnnieB

The 12V battery won't back-feed to the 48V battery pack through the 48V to 12V converter. It's a one way street electrically.

However, the converter's output may be less than the at-rest voltage of a fully charged 12V AGM battery, which is 12.84V for Trojan brand.

Also, the absorption charge voltage for a 12V AGM is 14.4V and float is 13.5V, both of which is likely lower the the output voltage of the converter.

---------------
A 16V Super-Capacitor could be used in place of the 12V AGM battery, eliminating the charging voltage issues.