I have a 2006 era Schumacher 12V, 10 amp battery charger "Ship to Shore" model that has a rocker switch that allows for "manual" or "automatic" mode. It seems to work great, fairly heavy compared to the new "smart" chargers. It has an analog needle gauge that moves towards 0 Amps as the battery nears charged, and a green light comes in when charged. Is there any real advantage to battery life and health if I switched to a newer, microprocessor controlled charger? I mainly use it to charge 12V marine group 24 batteries, for my small travel trailer. Reviews seem to be mixed on these newer units?
12V battery charger question
- Thread starter Metolius
- Start date
You mean something like this?
Works so poorly I've kept it around for maybe 25 years. I guess I should have kept the receipt.
Works so poorly I've kept it around for maybe 25 years. I guess I should have kept the receipt.
I had one of those, finally died. I tried several times to repair it, turns out the transformer had an internal short.
They are awesome to have on hand for when 'smart' chargers are too smart for their own good.
Not 110v charger related but have you considered adding a small amount of solar to the trailer? Ours came with a 50 watt panel that worked great as a battery tender when we weren't using it. Of course I've gone super far off the deep end with it, but having the solar and not having to worry about any kind of charging is nice.
I have resuscitated 40 or so batteries in the past 4 months at a new car dealership. Tested at 7 volts or less to start. Haven't lost one yet. Mostly AGM main and stop start batteries. I'm a fan.
Yea, but he's in Oregon and will have to deal with temperature, and charging from the truck when in use, so not just a straight up easy drop in.
But yes, lead chemistry is largely dead for travel trailer/rv use. LifePO4 is pretty much ruling the day now.
Today's small chargers all use a switching supply to reduce production cost. Almost all of them are designed and built as cheap as possable, resulting in units that don't last anywhere near as long as the old heavier chargers that use a big transformer, instead of a switcher type supply.
Those old big units are much more reliable.
Those old big units are much more reliable.
The old school chargers are fine when the goal is to just pump as many electrons as quickly as possible, with the caveat that they ain't that smart, and it's still possible to cook the battery if neglected.
Most smart chargers are more "low and slow" and more suited to be left unattended.
There's a place for both.
Most smart chargers are more "low and slow" and more suited to be left unattended.
There's a place for both.
I have an older transformer based charger and some new smart chargers. I would not leave my old school charger unattended for much time, but when I just want to charge a battery, I always pull out the old one. If I am looking to maintain a battery, I let the smart charger do its thing.
Had one of those for years, before smart chargers. They work well, but, you really gotta watch the battery. Take the caps off, check the cells, top off, etc. GREAT for a dead battery ( not frozen or shorted out, just discharged ) Now I strictly use Noco Genius chargers for maintenance. Can't beat em. I wouldn't chuck it for a dead battery. Smart charger will take forever to charge that up. Had an FLA hooked up to that Schumacher, got so hot I thought it was gonna blow. Old school technology, but still has a purpose for discharged batteries. Just gotta watch it, especially if charging indoors.
f355spider
$50 Site Donor 2025
THIS.
I still have an old school charger with a boost function, but they really cannot be trusted for anything more than a few hours quick charge at 15 or 20 amps. Hell I wouldn't even trust it on the 2 amp setting for more than a day. I have seen it boil electrolyte on smaller batteries, even though the "green" led says fully charged and it is not supposed to be still charging.
For any long term maintenance I have Battery Minders or Pulse Tech.
There's an old thread here on bitog where the thread starter wondered why his very old charger was charging too fast and putting out too high of a Voltage.
I said that many decades ago, common house AC Voltage was 110 V AC RMS, and power companies have been slowly increasing it so now it's usually between 122 V to 129 V AC RMS. And if you put higher AC voltage into a transformer the output ends up being higher. In that case, too high.
So, extremely old chargers may have other problems because common house Voltage has increases significantly since they were designed and built.
Additional note, sometimes increasing input voltage will fry a transformer. It depends on how it was designed and built.
Also, there are some transformers that are designed to run with a saturated core that will limit and somewhat regulate the output voltage. But those are extra heavy and expensive and you won't see those in a charger. Old professional dark-rooms often used them to maintain a constant voltage to the lightbulb to have consistent brightness for printing photos from film.
I said that many decades ago, common house AC Voltage was 110 V AC RMS, and power companies have been slowly increasing it so now it's usually between 122 V to 129 V AC RMS. And if you put higher AC voltage into a transformer the output ends up being higher. In that case, too high.
So, extremely old chargers may have other problems because common house Voltage has increases significantly since they were designed and built.
Additional note, sometimes increasing input voltage will fry a transformer. It depends on how it was designed and built.
Also, there are some transformers that are designed to run with a saturated core that will limit and somewhat regulate the output voltage. But those are extra heavy and expensive and you won't see those in a charger. Old professional dark-rooms often used them to maintain a constant voltage to the lightbulb to have consistent brightness for printing photos from film.
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Basicly, old transformer type chargers can sit for years and still work when needed. But they are dumb and can ruin a battery if left on too long.
A few rules of thumb when using one is think of most batteries as having about a 50 Amper-hour capacity. If you charge it to about 1/4 charge and it's it's warm out, that's good enough to start a vehicle. In winter try for about 1/2 charge.
So, in summer about 13 Amper-hours is enough. In winter about 25 Amper-hours is enough charge to start a vehicle.
So, if your take the number of Amper-hours you want to put into a battery and devide that by how many amps your charger is putting out, thats how many hours it will need to charge.
Ya never want to over-charge. That will ruin a battery.
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The newer type can have a capacitor go bad in them from age. So even if seldom used, if you go to use it someday when it's a few years or more old, it might not work.
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Some old ones with transformers can be damaged by accidently connecting it up with the wrong polarity. So take your time and double check when using one of those.
A few rules of thumb when using one is think of most batteries as having about a 50 Amper-hour capacity. If you charge it to about 1/4 charge and it's it's warm out, that's good enough to start a vehicle. In winter try for about 1/2 charge.
So, in summer about 13 Amper-hours is enough. In winter about 25 Amper-hours is enough charge to start a vehicle.
So, if your take the number of Amper-hours you want to put into a battery and devide that by how many amps your charger is putting out, thats how many hours it will need to charge.
Ya never want to over-charge. That will ruin a battery.
---------------
The newer type can have a capacitor go bad in them from age. So even if seldom used, if you go to use it someday when it's a few years or more old, it might not work.
---------------
Some old ones with transformers can be damaged by accidently connecting it up with the wrong polarity. So take your time and double check when using one of those.
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I'm not entirely sold on the "smart" chargers either, and have a fresh example to cite.
Needed to recharge a dead Exide 35 that was drained by a dome light from a door ajar.
Could have broken out the Sears (Schuey) 10 amp for a quick-and-dirty, but figured I'd put it on the CTEK 4.3 and let it do its reconditioning thing, which took the better part of a day and half, maybe even more. Six- or seven-step process. Fully automatic, and idiot-proof, right?
When I went to reinstall the battery, noticed the case was bulged. I wish I could, but can't recall if it was already like that before the process, but it definitely is now.
I'd like to think I would have noticed if it was already bulging, but regardless, the seeds of doubt have now been planted.
It's an old battery that will be due for replacement in the not-so-distant future anyway, so no big deal, but now I don't know if I can trust that mode with others.
f355spider
$50 Site Donor 2025
That is unfortunate. I have had zero issues with about 8 different brands. But focused recently on the Battery Minder and Pulse Tech because the desulfate process they both use appears to work much better than anything I have owned previously. The Pulse Tech is a recent addition but the Battery Minders have clearly brought back two batteries that were not fairing well with near daily use on a Granite Digital Save a Battery or older Griots Garage battery tenders. I switched to using Battery Minder and over the course of a couple months both slowly came back to slightly over their rated CCA values
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