Whats your recommended 12v auto battery charger?

[Gr8ful]

The DC power supply thats coming is 0-30v &0-10a & has both digital readouts, knobs to adjust & all the cables for $45 total. On the forklift which was 36v & came with a huge 3 phase charger & I have 3 hase but don't like it running if I'm nt in the hanger so if you pick the right 3 spots you could charge with one of the ro around as volts.

[TWIH]

Have you checked Craigslist, Offer up, or Let Go for a quality used Charger?  Ive noticed the prices on Facebook Marketplace are very low sometimes.

I look at craigslist for vans but nothing else.

[TWIH]

I have a Stanley 15a /40a engine start charger. I bought at Wallys a few years ago..~$50
Surprisingly , it outputs 14.7 through entire cycle till floating kicks in around 3a.
Seems to self limit to 15.4a if batt is very depleted.
(Checked with external Fluke digital meter)

Not bragging , but reporting what it is...

Thanks. You are addressing the issue which is occasional non-technical usage.  I just want an alternative to the HF Centek which has a 45% one-star rating (worst Ive ever seen) on Amazon.  I’m very aware that HF electronics are normally suspect (sourcing for lowest price point usually isn't a good thing) so I’m trying to take advantage of any possible deals this time of year.  

I have a working charger, (on 2 amp anyway) just no real idea of what the programmed multi-step charging levels or timeframes are. It has been voltmetered as showing 14.42 on a (slightly or whatever SOC) discharged battery so I know thats likely its max output. It also allows at least 12.76 for a resting voltage, as when I checked it after 8 hrs overnight (green light on the whole time) that’s what the battery terminals read and there was no activity on the charger.  Upon unplugging and unclamping then replugging/clamping the unit, it immediately went back to the 14.4 charge rate then within about 2 minutes it clicked off and the fuzzy feelings green light came on.  (So I know it does shut off when it thinks the battery is full).

I read a criticism of the “automatic” smart models as simply being “dumb” programming thats all fixed, no battery voltage checking, just going through their program no matter what.  Solar charge controllers are much the same it seems. 

SW’s wacked out Schumaker with its 16+ volts charge rate is scary as you could easily ruin an expensive AGM (or any sealed battery) that way.  Pretty much what I’m trying to avoid is charging over 14.8 and a real 3 stage thats based on battery sensing. I will probably end up just keeping this one until I make the change (if ever), but a 2 amp charge rate just wont work on a 220 amp house system, me thinks...

sigh, why is all this so f’ing complicated?

[tx2sturgis]

My 12 amp Schumacher has the options of Standard, AGM, and GEL battery selections. The GEL setting is the least aggressive and I have used that setting with small sealed motorcycle batteries....no issues there. The 'Standard' setting is more aggressive and will cause some bubbling with flooded batteries...only a little, and not enough to damage the battery...this is the situation with my 12A unit.

Yeah the fan is getting noisy but its been about 10 years or so....I guess I need to open the case and drop some oil in the fan bushing.

[TWIH]

Another question. I’ve read on some of the automotive chargers Q&A’s that rv’ers with the 2 golf cart batteries series-wired together are not getting both batteries to the same charge (by putting the positive clamp on one and the negative on the 2nd battery). Any thoughts on this?

I couldnt add this quote from a manufacturer of the Ampeak 12v charger to my post above, but heres an example of the programming:
Begin quote:

“Reconditioning Function:
It adopts high voltage up to 15.8V to stimulation battery, mainly for the bad battery caused by short circuit or low-softening plate.

The working cycle is 5 cycles, each cycle is 4 hours. If the charger test concludes that the battery (using the object) is still less than 12V after the repair cycle, the dead battery is determined.”

End of (chinglish) quote.

[sternwake]

When paralleling 2 12v batteries, it is best to take all loads from, and place charging sources on, the - of one battery and the + of the other.
When putting 6v batteries in series, to form a 12v battery, one HAS no other option to put one - cable on one battery1 and the + on the battery2, as if one put both clamps on the same 6v battery, they are hooking a 12v charger to a 6 v battery.

Automatic EQualization charges are not something I would want an automatic charger to decide to initiate on its own. 15.8v, is too high for some electronics which might still be hooked to the battery. these EQ voltaegs can indeed remove some sulfation, and in fact are more effective than the 'pulse desulfation' chargers which people seem to believe are magical battery restorers.

Pulse desulfation is a marketing buzzword. Its been proven to have o more benefit on sulfated batteries than a chrging source holding them at equal voltage for the same duration. the US navy tried this way back when on diesel electric submarines and found the pulses damaged the plates faster. YOu will not find a lack of glowing testimonials though on Amazon or on forums.

Trojan and Rolls Surrette spec 16.2v for EQ charges but Trojan a few years ago spec'd 15.5v.

A few years back people were wanting the harbor fright manual charger as nothing else was easily obtainable that could push a single 12v battery to 16v if left on long enough.

https://www.ebay.com/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=pd+9245&_sacat=0

The link above will be able to take much better care of a pair of gc-2s so much better than any garage style charger. It is worth the price. Dont let the lack of DC cables put you off, Cut an older set of 6awg or thicker jumper cables in half and you will have an incredibly powerful an capable portable charger that will smoke anything deisgned for the garage and the occasional flat
starting battery on a neglected vehicle which sat too long or had its dome lights left on overnight.

Remember the charger you are getting is not going to be on a small capacity starting battery, it is going on a pair of GC-2's with 3x or more capacity, and which if depleted enough can demand the charger to run flat out 3x longer, or more, which the designers never intended. Well they might have but the bean counters neutered them and cut fractions of pennies off of everywhere.

Yes any charging source can work, and can get batteries towards full, perhaps nearly full and rarely truly full, but a garage charger on a pair of GC-2's is like taking an Econobox with 14 inch rims and 4 inches of ground clearance offroading and wondering why you got stuck and broke something.. You seem to be trying to find the best econobox to take offroading, and unless somehere has tried to take that specific econobox offroading, they/we can only guess how well it will do and how far it can get.

Once stuck and miserable, one will wish they paid more and bought the 4x4 instead.

That said my Schumacher sc2500A, rated at 25 amps is providing 29.62 amps/394 watts as I type and only has the battery upto 13.6v so far. In another 60 minutes or so I have to be careful of voltage exceeding 14.8v. Even on the AGM setting. It can't be trusted. nor left alone. My Meanwell, can. it will never go above the voltage I have chosen. The PD can, it will never go above absorption voltage, either 14.4 or 14.8 depending on the version bought.

Any random garage charger with chingrish instructions, well you will have to tell us what it actually does, but seeing as how you have not bothered to check the max voltage or ampergae used to get there of the Cen Tech which you have, yet don't trustt.....well good luck on that offroad trail in a lowered prius with bald tires.

Seeking 'best cheapest' will be regretted, its just a matter of time and delusion for that duration.

[TWIH]

SW I appreciate the info. I have monitored the Centek and as high as its ever got for voltage is 14.7x. It hasn't ever gone above that. As far as amperage, I don't have a DC clamp meter or anything but I do all the charging on the low 2 amp setting at present. (I found out that the 10 amp swings the dial back and forth and the unit "clicks", so my confidence in that amperage is non-existent and there's YT videos about the same thing happening with other Centex chargers on 10 and 2 amps. Thus the wondering about other popular and 4 star Amazon rated brands. I can get any of three brands of 2/10/25 amp chargers for less than $50 right now off Amazon.

I get your econobox vs 4x4 comparison, just trying to find a way to have some acceptable charging when the occasional stopover at a relatives house occurs and there's a free ac plug-in. For that it seems that the occasional use of a 10/25 Schumaker, Stanley or Ampeak 12v charger, while far from ideal, would suffice. Mind you, I have to drive hours (from 2 hours for visiting one relative to 16 hrs for another) so if I had a CD solenoid or a B2B system, there'd be a lot of bulk charge done that way. It's the finish charge up to 100% that's hard to get.

I presumed that there may be others in a similar situation who don't have an ac plug handy 95% or more of the time. For them its either a genset, lots of solar or a B2B. The other 5% of the time would/could be the cheapo 12v charger, I thought.

Whatever, if it's not meant to be then its isn't. The number of boating and fishing forum posts I've read suggest that the norm is to recharge the marine or AGM trolling motor batteries overnight/all day before the trip on a std automotive battery charger. If it works for them, why not for us? Now they likely don't have two six volt GC's linked together but maybe they have two smaller 12v AGM's in parallel. Dunno', just seeing what this forum thinks about it.

[Trebor English]

The number of boating and fishing forum posts I've read suggest that the norm is to recharge the marine or AGM trolling motor batteries overnight/all day before the trip on a std automotive battery charger. If it works for them, why not for us? 

They go fishing on Saturday.  That makes it one cycle per week during the time when fishing happens.  If the battery lasts a year that might be 12 cycles.  My cheap flooded trolling motor battery has lasted 3 years because it gets fully charged regularly and I seriously avoid discharging it more after a partial charge.

Give a man a fish and he'll eat for a day.  Teach a man to fish and he'll sit in a boat and drink beer all day.

[TWIH]

The number of boating and fishing forum posts I've read suggest that the norm is to recharge the marine or AGM trolling motor batteries overnight/all day before the trip on a std automotive battery charger. If it works for them, why not for us? 

They go fishing on Saturday.  That makes it one cycle per week during the time when fishing happens.  If the battery lasts a year that might be 12 cycles.  My cheap flooded trolling motor battery has lasted 3 years because it gets fully charged regularly and I seriously avoid discharging it more after a partial charge.

Give a man a fish and he'll eat for a day.  Teach a man to fish and he'll sit in a boat and drink beer all day.

Than you for your reply. I can't go the complicated instrument or hobbyist route, this is only for what, 3-4x a year charging needs. I might not even need to buy a charger since all relatives have their own versions for their own vehicles. Trouble is, the SIL's little Honda Civic has a 2 amp maintainer, so I'd need something bigger while there.

Do you only recharge your marine 12v from the alternator, use alternator and solar or what? 

I understand that shallow cycling gives longevity, and if an individual does not run a powered roof fan or a 12v compressor fridg, (and doesn't constantly stream movies or use a gaming device), then their electrical loads are reduced such that a minimal house battery is needed (like your setup). 

I've even considered one of those "solar generator" misnomer Li Ion devices around the 240 watts size (don't have the coin for the new 500 watt ones). They are small enough to be taken into a coffee shop, bookstore or library and plugged in while I loiter there. Trouble is they usually charge so slowly that if depleted can take 8-10 hrs. Guess the trick is to not fully deplete them!

The WM cheapo marine battery might handle basic loads but I don't believe that I could make it work given a roof fan (in the summer) and a compressor fridg. Thus the question for occasionally charging the two GC's.

Despite the electrical gurus best advice, I'm just not that deep into electronics or making up my own equipment. I simply want a basic recharge option that's cost-effective, simple to use and has some protection circuitry built in.  Currently for my PT goings in and out, the craptastic Centex 2/10 plus driving seem to work fine, but that's only PT use with a starting battery as my only source (yeah I know, risky but I have two 17 ah lead acid jump boxes besides). 

Thanks all, maybe this is frustrating for those of you with access to ac but I don't plan on having that luxury.

[Roadtripp]

https://frederick.craigslist.org/bpo/d/f...05431.html
https://stjoseph.craigslist.org/for/d/be...50907.html
 Here’s a couple used Marine chargers. I have loads of chargers. If your in NW WA I’d give you one of my 10 amp chargers.