If I get a float charger for a 12V battery, can I use it on two 6V GC batteries hooked in serial?


https://www.harborfreight.com/automatic ... 42292.html

Should be fine. as long as the two six volt batts are the same capacity.

I think the bigger problem here is if the batteries are gel cells if that is what the GC stands for ---- they need a specific charger - IF you want them to work for any length of time....

Although pricey, I was going to recommend this....
https://www.batteryminders.com/6-volt-d ... ldwide-use
Until I saw that it specifically states 'NOT for use with gel cells'.

I have two 12v batteries in series (24V) that run my mills vertical winch and I keep them charged with an old medical wheelchair charger that I got at a church rummage sale for $5 ($300 charger when new). It blinks fast when its charging in high, then adjusts down to a slow blink when they are pretty good, then it lights solid when they are charged. It gets powered up any day I run the mill and I flip the power on for that area.

Both batteries are similar in size but not exactly the same size, brand or exact style. They have been working FINE for 5 years. They were used wrecking yard batteries.

You can bend rules a bit, just don't push it way to much.

I think you will be fine. What are the 6v batts for/purpose/use/loads?

GC= Golf Cart lead-acid wet batteries.
The one at HF is on sale for $5.

Gels dont really need a special charger unless they are very dead. Even then there are ways around that. It all has to do with internal resistance of the two types.

The charger is a NO-NO because its a cooker/desulfator. It pulses high frequency in hopes of cooking off sulfated plates. They don't work either. They are just a gimmick.

If you have a sulphated LEAD ACID battery the best way to desulfate it is with an old big box style jump box on HIGH. COOK it until its sizzling with the caps cracked so it can vent. Monitor is a few times and hour and NEVER let the top of the plates become exposed. Keep adding sulfuric acid to it as needed. Ive brought back ten year old batteries this way.

Despite what the "youtube wizards" tell you NEVER put epsom salt in a lead plate battery either. It will work great again, then go to shit rapidly.

Batteries are a simple yet very misunderstood device.

My bad --- it didn't register 'Golf Cart' when I saw GC.... I immediately thought gel cell.....

I'd spend a little more to get a better charger, but yea it'd work.

I am with PMB. I can't tell you how many batteries I've left on a trickle/float charger for winter and they're toast by spring. I've had FAR greater success by rotating a standard charger around every month or so to different batteries.

The small watercraft batteries in Jet Skis seem like the worst for this. They last a couple years then die over winter despite being trickle charged. It seems like trickle chargers are overhyped, but I still use em occasionally.

Just my opinion,

I would NEVER leave a charger on 24hours a day. I would never leave a charger on unattended. Even if its meant to be, I would not trust it. I would not leave a seasonal battery IN the vehicle to be maintained.

A lawn mower or quad or jetski or MC I would remove the battery and hook it to a "float or trickle" charger that was on a circuit like my shop lights so it charged when I flipped the lights on and was present but not after I leave.

Good advice. I usually pull them out, but the key seems to be cycling the power on and off rather than leaving on 24/7.

Couple years ago I had my boat on the built in charger/maintainer outside with 2 Cabelas deep cycles. Something happened at some point - when I opened it up the charger was fried, both batteries had cracked/swollen/busted open, my stereo was shot and it took out the Smartcraft multifunction gauge (Many hundreds and discontinued, of course - so at least I got to upgrade to a fancy new gauge!) despite the battery switch being off (stereo memory and Smartcraft both require direct wiring)

All in that one cost me about $1500 between 2 batteries, Smartcraft gauge, charger & Stereo.

Learned that lesson the hard way!!

I don't really trust HF for electronics like that

I picked up another charger at Costco a few months ago. This is the same one but Costco has them for ~$35:

https://www.amazon.com/Duracell-DRMC4A-Lithium-Battery-Maintainer/dp/B07MW39STH/ref=asc_df_B07MW39STH/?tag=hyprod-20&linkCode=df0&hvadid=366338088421&hvpos=1o1&hvnetw=g&hvrand=2925869752415822186&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=1027773&hvtargid=pla-783997336059&psc=1&tag=&ref=&adgrpid=79954179487&hvpone=&hvptwo=&hvadid=366338088421&hvpos=1o1&hvnetw=g&hvrand=2925869752415822186&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=1027773&hvtargid=pla-783997336059

It will switch between 12V/6V

Right now I have it on my car (that I don't drive) but I bought it to mount in the tool box of my dump trailer. So far so good, it hasn't cooked the battery

The batteries should be the same type, capacity, and purchased at the same time. Any variance in internal resistance can cause one battery to be slightly more charged and the second battery to be slightly discharged. Over time, as those differences increase, you end up with one battery being under charged in the other battery being severely overcharged. As cheap as battery chargers are these days, you'd be better off getting a multi-bank 6-volt charger.

Also, while SLA deep cycle batteries like GC2s are designed for deeper discharge, they are still generally only rated for maximum life at 50% depth of discharge.

A true deep cycle like the gc-2 is designed to withstand some of the negative effects of a deep discharge. But can still be damaged.

A starter battery will have multiple thin plates, whereas a deep cycle battery will have few thick plates.

You will also need to balance any loads that are pulled off of the 6-volt side, if you have any. It's just easier to get a 6 volt charger.

Anyone else want to stop and question what the newlywed is doing with 6V golf cart batteries?

Just throwing it out there...

Please respect the policy on spoilers

backup plan. AEDs are too expensive.

I was guessing nipple clamps