Whats your recommended 12v auto battery charger?

[sternwake]

I put an Iota dls-45 in a rig at least 6 years ago. I instructed him to plug in for 3 days after an outing, as he would expect to drain the wally world dual group 27s dead each night . He got 2.5 years from those batteries and, is on his 3rd with some costco interstate golf cart batteries and says he forgot what the inverter alarm sounds like and thinks perhaps it is broken.

Every time I check them yearly with a hydrometer the specific gravity is about 1.260 to 1.265 and not very much time is required at 16.2 to bring them all upto 1.270. A good sign. I unscrew the meanwell p[ower supply from my cabinet tin order to get them to 16.2v.

His Iota only allows 14.8v for 15 minutes, then drops to 14.2v for a period of time then two lower stages. Can't really remember for sure. That voltage is at the output terminals not the battery. The thickness and length of those cables matter much more with an Iota since it only holds 14.8 for 15 minutes
Voltage drop on the cabling at 40 amps is considerable, so 14.8v at the output terminals is not 14.8v reaching the battery

But they have a whole bunch of different iq4 plug in devices which can change the charge profile. I've not really investigated all those options.

I would still prefer the Progressive dynamics pd9245-14.8
http://www.bestconverter.com/PD-9245C-14...fBRn4NKit8

I don't like the proprieter of that site, but it is the only direct link to the 14.8v model. See if you can bypass him and got PD directly

https://www.progressivedyn.com/

Manufactured in Usa ^

While some will say 14.4v will never charge a battery like Trojan which specs 14.82v absorption voltage, that is not true, it will just take longer to fully charge. near the end of the battery's effeetive lifespan 14.8 might will likely stretch out the time it takes for failure, provided one checks water regularly and does not allow it to drop below the plates. Old batteries will require lot of water, and time at absorption.

BOth PD9245's I installed had 14.56v absorption.

The PD allows for a button push and 4 more hours of 14.56v, or hold it a bit longer and force it to 13.6v, or hold it a bit longer and force it to 13.2v. It will automatically seek 14.4v when plugged in and go through those three voltage stages on its own.

If one has 5 hours to plug in and recharge, the PD will likely be able to bring the batteries to a higher state of charge but one might need to be there at hour 4 to press the button an keep it in 14.56v absorption.
If one has 12 hours either Iotadls-45 or PD9245 will both have them at or very near full charge.

Note PD calls their 4th stage equalization. It is not an EQ! it is a 15 minute blast to gassing voltage ( 14.56v) every 18 hours to destratify the electrolyte.

NOte Iota calls bulk 14.8v, and absorption 14.2. I'd think it would be better called a '2 stage absorption.'

BUlk is when the charging source is outputting its maximum rating. constant 45 amps in teh case of the PD or Iota 45 amp models.
Absorption is achieved when the combined voltage of battery and charger at the charger output reaches the maximum allowed. say 14.8v.
Absorption is constant voltage stage, as the amperage required to maintain that voltage tapers.

Float is the voltage esigned to not allow discharge of the battery and keep it fully charged with minimal overcharge. Ideally it would be battery temperature compensated, as would all the above stages. Few converters/ charging sources are.

YOur prospective batteries will be much happier with either the Iota or the PD, than any garage charger, and if it doubles the battery life, it has nearly paid for itself on the first set of batteries.