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After couple hours of research, I am still unclear on this:
I would like to attach my battery charger/maintainer to my truck without disconnecting the battery post. I have a charger with trickle.
Is this safe to do?
Does connecting to one battery keep both charged?
Which battery should I connect to if this is safe to do?
Anyone doing this that can chime in?
Connecting your trickle charger to one will charge both, they are wired in parallel, there is no real right or wrong battery to connect to, some prefer the positive off one and the negative off the other, but it really doesn't make much of a difference.
As far as safe to do it depends on your charger. Your don't want to overcharge the batteries or cause the water in the batteries to boil off, that will just kill your batteries.
I connected my maintenance charger to the passenger side battery terminals. On my '01, with lead cable ends, there was enough threads on the bolts to add the ring terminals of the charger wires and an additional nut. Also, the passenger side was closest to the outlet in my garage.
What charger do you plan on using? The charging rate, thus the charger, needs to be sized to battery ampere capacity. The small 1/4 amp maintainers are OK for a single car battery.
What charger do you plan on using? The charging rate, thus the charger, needs to be sized to battery ampere capacity. The small 1/4 amp maintainers are OK for a single car battery.
It is "15 amp rapid charge" "3 amp maintainer/trickle charger" "automatic smart charge" "reverse polarity protection"
It sits on top of my under-hood fuse box and clips to the driver's-side battery.
Though the photo looks like 15-amp, there's a decimal point that isn't real clear, and it's really only 1-1/2 amps, but "smart", so it drops off to a mere trickle to keep them topped off.
It's plugged in anytime the truck is sitting in the driveway.
It's one of two I use. The other is on my RV's battery.
Pick the right one for your battery. I have the flooded versions of the Battery Minder Model 2012 on our flooded battery vehicles. On the Bronco I have a 15 year old Optima Blue Top D31M AGM which I brought back to life after bulk charging it to 10.5v with a Napa Battery Charger, 80/20 - 10/2 Amp, 12 Volt, NBC 85620 and then running the big Battery Minder 12248 (and putting it on every night when we get home from work to continue to desulfate it) and it is starting and running the vehicle just fine and now being maintained/desulfated every night by a Battery Minder 1200-AGM. I will be making brackets for the Battery Minder for under the hood in the vehicles. They are connected to the batteries by Battery Minder fused ring terminals and I just let the three prong plug hang out the grill like a block heater.
And using the same Napa bulk charger and then following it up with the same Battery Minder we have been running our jet skis 3-4 times a week on 5 year old (purchased in 2010 and sat in the skis NEVER used) 12v flooded cell lead acid batteries. They are now being maintained with Battery Minder Model 1500's.
I have that type of Schumacher, if not that exact model, the plastic "lunchbox" style. The problem with that one, it will not work in cold weather. Below about 35°F, it won't turn on and the digital LCD display horks with gibberish, etc. Have to bring it inside and thaw it out. Pretty sad. I have an old school Schumacher "dumb" charger, and it works great.
With dual batts you want something that will put out some real juice, with adjustable/selectable settings. 15 or 20 amps is basically a trickle charge with parallel batts. The tiny microamp maintainers will never be able to equalize mismatched batts.
Update: The Blue Optima finally died earlier this year after 17 years. But I was plugging it into a Battery Minder most weekday nights for years (just in case you consider that cheating). Rest in Peace.
Most of our vehicles have a plug hanging out of the grill (kinda like the 7.3 engine heater) but it attaches to a Battery Minder paired to that vehicle's type battery.
Others will have to comment on the NOCO and Schumacher, I have no experience with them.
It sits on top of my under-hood fuse box and clips to the driver's-side battery.
Though the photo looks like 15-amp, there's a decimal point that isn't real clear, and it's really only 1-1/2 amps, but "smart", so it drops off to a mere trickle to keep them topped off.
It's plugged in anytime the truck is sitting in the driveway.
It's one of two I use. The other is on my RV's battery.
Got them for about $25 each on eBay.
Pop
This is exactly the same charger I use on my L99, and exactly the same place I have it mounted. I have it secured to the top of the fuse box with HD Industrial Velcro and I have mine hooked up to the battery with ring terminals. I routed the 120v plug down by the block heater plug, its simple & easy to plug in when the truck is not in use now.
