Battery charger recommendation

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Got in the new Rav4 yesterday only heard weird clicks when I tried to start it. Battery read 7.5 volts across the terminals. Looks like the light in the cargo area was turned on and drained the battery. Pulled out my old Schumacher 10 amp charger and hooked it up. It's a low frills charger. Wife asked how long it takes to charge it. I just shrugged and guessed 2.5 hours. It started after 2.5 hours and we went for a hour long drive. The start/stop feature in the car will only work on a fully charged battery and it wouldn't work until we pulled into the driveway back home. Wife suggested we leave the charger on all night to be sure the battery was fully charged but I explained my charger will cook the battery. It's not smart. What are suggestions for a reasonably priced smart charger that will charge a battery in a few hours without cooking it?

This is a pic of my charger I found online.

148190_7345566.jpg
 
You can charge manually. Check voltage at the battery periodically with the charger still running. When the voltage reaches about 14.6, it is full, so turn it off. That is actually all that a basic automatic charger does.
 
I have two of the Schumacher 2/10/50, starting and deep cycle automatic smart chargers w/ battery condition indicators and I like them. They work well on the various auto/marine/aircraft, flooded and AGM, batteries, but both have had the clamp to cable connections fail after relatively little use. The clamps are crimped onto the copper strands and the jackets but the leads fail at the strands. Frustrating. I wound up crimping ring terminals to the leads and attaching them to the clamps.

I'd still recommend the higher end Schumachers, but, assuming the design hasn't been improved, I'd reattach the leads to the clamps preemptively.
 
Originally Posted by Leo99
Got in the new Rav4 yesterday only heard weird clicks when I tried to start it. Battery read 7.5 volts across the terminals. Looks like the light in the cargo area was turned on and drained the battery.


Most cars made the last 10-20 years have automatic battery drain cutoff that turns off the lights after 10-20 minutes.
 
I'd just buy a BatteryTender or any decent maintainer and this way you can connect it to your battery(permanently if you'd like) and leave it on all night if you want. And still hold on to your old Schumacher for completely dead batteries. Tenders/maintainers won't bring up a battery that is run down too low the way your Schumacher charger will.
 
Originally Posted by atikovi
Originally Posted by Leo99
Got in the new Rav4 yesterday only heard weird clicks when I tried to start it. Battery read 7.5 volts across the terminals. Looks like the light in the cargo area was turned on and drained the battery.


Most cars made the last 10-20 years have automatic battery drain cutoff that turns off the lights after 10-20 minutes.


That's what I thought. I put in aftermarket LED bulbs in the cargo area and cabin. The stock bulbs are way too dim. Maybe that prevented the cutoff?
 
Originally Posted by Kawiguy454
WallyWorld sells Shumacher smarter chargers. Youll pay more for more features. I bought a small CTEK smart charger that Jay Lenno uses and it has not failed me. It doesent charge at 15 amps but is fully automatic with different cell types and a rejuvenate mode.

https://www.amazon.com/dp/B000FRLO9Y/ref=psdc_15707061_t1_B07C8G3BKX


Great little charger, I have a similar one same make and great built quality!
 
Originally Posted by atikovi
Originally Posted by Leo99
Got in the new Rav4 yesterday only heard weird clicks when I tried to start it. Battery read 7.5 volts across the terminals. Looks like the light in the cargo area was turned on and drained the battery.


Most cars made the last 10-20 years have automatic battery drain cutoff that turns off the lights after 10-20 minutes.


My '12 Mazda3 will drain the battery if parked for more than a week. The dealer said this is normal ([censored]). I travel a lot and can be away for a month or more. My Schumacher has a 110 amp starter mode, 15 amp fast charge, and a 2 amp trickle mode. But it is so old that I don't think it is smart enough to power down after the battery charge is full and the loud hum it makes has me convinced that it is sucking a lot of juice all the time. So...

Originally Posted by Char Baby
I'd just buy a BatteryTender or any decent maintainer and this way you can connect it to your battery(permanently if you'd like) and leave it on all night if you want. And still hold on to your old Schumacher for completely dead batteries. Tenders/maintainers won't bring up a battery that is run down too low the way your Schumacher charger will.


This ^^. So I got a Schumacher trickle charger and it lasted ~6 years. The replacement Stanley 1 amp crapped out in 1 year. Now using a BatteryTender Junior. Will see how long it lasts.
 
Originally Posted by whatnext
My '12 Mazda3 will drain the battery if parked for more than a week. The dealer said this is normal ([censored]). I travel a lot and can be away for a month or more. My Schumacher has a 110 amp starter mode, 15 amp fast charge, and a 2 amp trickle mode. But it is so old that I don't think it is smart enough to power down after the battery charge is full and the loud hum it makes has me convinced that it is sucking a lot of juice all the time. So...

The FSM for your Mazda will specify a quiescent current draw for the vehicle. It is an easy test to determine if the vehicle has a parasitic draw above that limit.

My old BMW has a series of step-down values that decrease immediately after shutdown. IIRC the final value after four minutes or so is less than 20mA. The only reason I know this is because it had a diode failure in the alternator which caused a 800mA continuous draw.

There's no way any vehicle should drain a battery in a week unless there is either something wrong with the vehicle or with the battery.
 
Originally Posted by kschachn
The FSM for your Mazda will specify a quiescent current draw for the vehicle. It is an easy test to determine if the vehicle has a parasitic draw above that limit.

My old BMW has a series of step-down values that decrease immediately after shutdown. IIRC the final value after four minutes or so is less than 20mA. The only reason I know this is because it had a diode failure in the alternator which caused a 800mA continuous draw.

There's no way any vehicle should drain a battery in a week unless there is either something wrong with the vehicle or with the battery.


Thanks - FYI the battery dies between 1 and 2 weeks. The dealer said this is normal and didn't even suggest bringing it in. So I wasn't going to chase down the current draw. If I found it I doubt the dealer would lift a finger. So I just went with the trickle charging and has been my routine for 8 years. BTW - its still the original battery from 2012 but I am pushing my luck and will replace it before next winter. Also my other 2 vehicles can sit for more than a month and start fine.
 
I have two schumacher chargers, one small and one big... they both stay in the garage... I always go for my Silver Beauty.. its loud and makes a buzzing noise but its a workhorse. If i find another at a yardsale im buying.

[Linked Image from antiquesnavigator.com]
 
You have an approx 80 amp-hour battery, so four hours with that antique charger will bring it to an adequate level. And this is the "few hours" you were looking for.

Too much more than 10 amps is too fast without careful monitoring.

Your car drive and initial charge probably brought it up halfway or so.
 
For a 10A charger, currently I'd recommend the NoCo genius second gen 10A charger. It will boost flat (0v) batteries, has a power supply mode, and, most importantly, is temperature compensated.

I bought a 1A and 2A for evaluation. Can't endorse the 1A unit, as it doesn't seem to get a 122Ah deep cycle battery, disconnected from any load, to a maintenance float charge that is correct. Their 2A unit does. Ive not tested the 10A, but would assume it works the same.

There are a few others, the solar 20A selectable charger a few of us has works well, and for more $, the 25A ctek is god too. But the NoCo is best right now value-wise.

My perpetual favorite is the battery minder 12248.
 
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