Best way to charge and maintain a battery?

After further thought, with a small panel of a watt or two, a zener diode across the panel along with a blocking diode would limit voltage rise.
Super simple!
 
Last edited:
Originally Posted by circuitsmith
After further thought, with a small panel of a few watts, a zener diode across the panel along with a blocking diode would limit voltage rise.
Super simple!

That is a great idea!
 
Originally Posted by Avery4
Originally Posted by circuitsmith
After further thought, with a small panel of a few watts, a zener diode across the panel along with a blocking diode would limit voltage rise.
Super simple!

That is a great idea!

A little figuring:
1. A 1N5351B 5W 14V zener with a schottky blocking diode would top out at ~13.7V.
2. Or put a 1N400x diode in series with the zener (raise the voltage by 0.6V) and a 1n400x blocker for ~14V.
3. To handle more power 1N5341B & 1N5342B in series for 14.3V and a 1n5822 schottky blocker.
Should top out at ~14V. I can trim up or down ~0.3V by adding a forward biased schottky diode to the zeners or the blocker.

That third option I plan to try. Ebay here I come...
 
Last edited:
Originally Posted by Avery4
Hello everyone, I am wondering what the best way to charge and maintain a battery is. I have a couple of questions:

1. There are a bunch of high end chargers like my Noco G7200 that analyzes the battery and charges it in pulses rather than with a steady current and I am wondering if there is actually a benefit to this. They say it helps reduce sulfation and a bunch of other wonderful things and I am wondering if anyone has an opinion on this.

2. What is the best way to maintain a battery and keep it charged? Some chargers like my Battery Tender Plus (which I love by the way) go into a float mode and hold the battery's voltage at 13.2 volts or so to keep the battery topped off while others completely shut off when fully charged and turn back on and recharge the battery when the voltage drops below a certain level and then turns back off once recharged. Which method is better for the battery's longevity? I would think the more proactive approach of consistently float charging the battery at a low voltage would be a better method than the reactive approach of waiting for the battery to run down to recharge it, but any opinions on this would be appreciated.

All opinions are appreciated as always
smile.gif




Interesting timing. I just hooked my vehicle up to a CTEK MULTI US 7002 yesterday. It has two different charge profiles (Normal vs Cold Weather/AGM) along with a supply and re-condition mode. Basically set it and forget.
 
Last edited:
Originally Posted by BMWTurboDzl

Interesting timing. I just hooked my vehicle up to a CTEK MULTI US 7002 yesterday. It has two different charge profiles (Normal vs Cold Weather/AGM) along with a supply and re-condition mode. Basically set it and forget.



Excellent charger. I trust Ctek way more than noco.

I have two of them the 7002, and the big 2500.

My 7002 got dragged down the street and is still kicking and working perfectly.

Ctek is my second favorite charger brand.


UD

[Linked Image]
 
Originally Posted by UncleDave
Originally Posted by BMWTurboDzl

Interesting timing. I just hooked my vehicle up to a CTEK MULTI US 7002 yesterday. It has two different charge profiles (Normal vs Cold Weather/AGM) along with a supply and re-condition mode. Basically set it and forget.



Excellent charger. I trust Ctek way more than noco.

I have two of them the 7002, and the big 2500.

My 7002 got dragged down the street and is still kicking and working perfectly.

Ctek is my second favorite charger brand.


UD

[Linked Image]


I have heard good things about those Ctek chargers. What makes it better than Noco and what is your first favorite charger brand?
 
Last edited:
Originally Posted by Avery4

I have heard good things about those Ctek chargers. What makes it better than Noco and what is your first favorite charger brand?


Noco has had some quality control issues and had some failures as did my battery/ charger vendor, and some of their earlier units left the reservation with their voltages and algorithms. Too be fair I know they worked on that have made some changes. I haven't put on on a scope in a while. I hear from trusted sources they are pretty good now.

Even so I think Ctek and Optimate have better specs, build quality and algorithms and offerings

Between Ctek and Optimate, It's close.

The Optimate has a wider range AH it will smart charge, a more comprehensive display of charging and results and is built using thicker higher quality plastic

Also to be fair I had an optimate 7 die after being pressed into commercial daily service in an enclosed environment - my dealer instantly replaced it for me
but I have bought over a dozen optimate 6's from the same guy and use them EVERYWHERE.

UD

Heres a grip of my favs on a bench..

IMG_0234.jpeg
 
Originally Posted by UncleDave
Originally Posted by BMWTurboDzl

Interesting timing. I just hooked my vehicle up to a CTEK MULTI US 7002 yesterday. It has two different charge profiles (Normal vs Cold Weather/AGM) along with a supply and re-condition mode. Basically set it and forget.



Excellent charger. I trust Ctek way more than noco.

I have two of them the 7002, and the big 2500.

My 7002 got dragged down the street and is still kicking and working perfectly.

Ctek is my second favorite charger brand.


UD

[Linked Image]




Ya. I looked a Noco but I found their product descriptions confusing whereas CTEK seemed much more friendly for the average consumer. It was a "panic buy" since I still run on the original battery (6 yrs old) and the vehicle had essentially been siting since March. Warmer climate does help I guess since it took less than 12 hrs for the charger to reach "Float".
 
Noco doesn't state the low end of the chargers " smart" range where Ctek and Tecmate (optimate) do.
This becomes a problem for me when dealing with small batteries like a genset or motorcycle /ATV

According to Ctek the 7002 goes from 14-225

The Optimate 6 3-240

The noco 10 ?-230

The noco 5 ?-120


Nocos user guides all start with a 20 AH number for both the 5 and the 10 and they dont state how low an amperage they can put out.
Will the noco 5 or 10 try to slam a tiny battery with that kind of amperage?
I dont know because the UI doesn't tell me - nor does the manual.
That will kill a tiny 10 ah genset battery.


UD
 
Originally Posted by circuitsmith
Originally Posted by Avery4
Originally Posted by circuitsmith
After further thought, with a small panel of a few watts, a zener diode across the panel along with a blocking diode would limit voltage rise.
Super simple!

That is a great idea!

A little figuring:
1. A 1N5351B 5W 14V zener with a schottky blocking diode would top out at ~13.7V.
2. Or put a 1N400x diode in series with the zener (raise the voltage by 0.6V) and a 1n400x blocker for ~14V.
3. To handle more power 1N5341B & 1N5342B in series for 14.3V and a 1n5822 schottky blocker.
Should top out at ~14V. I can trim up or down ~0.3V by adding a forward biased schottky diode to the zeners or the blocker.

That third option I plan to try. Ebay here I come...


Update: I wound up building with two 1N5341B in series across the panel and a 1n5822 schottky blocking diode.
On the workbench it starts shunting away panel current (10mA) at 13.7V, 137mA output.
Open circuit voltage tops out at ~14.5V in full sunlight. With a few milliamps load that drops to 14.2V.
 
Originally Posted by circuitsmith
Originally Posted by circuitsmith
Originally Posted by Avery4
Originally Posted by circuitsmith
After further thought, with a small panel of a few watts, a zener diode across the panel along with a blocking diode would limit voltage rise.
Super simple!

That is a great idea!

A little figuring:
1. A 1N5351B 5W 14V zener with a schottky blocking diode would top out at ~13.7V.
2. Or put a 1N400x diode in series with the zener (raise the voltage by 0.6V) and a 1n400x blocker for ~14V.
3. To handle more power 1N5341B & 1N5342B in series for 14.3V and a 1n5822 schottky blocker.
Should top out at ~14V. I can trim up or down ~0.3V by adding a forward biased schottky diode to the zeners or the blocker.

That third option I plan to try. Ebay here I come...


Update: I wound up building with two 1N5341B in series across the panel and a 1n5822 schottky blocking diode.
On the workbench it starts shunting away panel current (10mA) at 13.7V, 137mA output.
Open circuit voltage tops out at ~14.5V in full sunlight. With a few milliamps load that drops to 14.2V.

That sounds like it should work well then
 
I have an update on my Noco G7200 charger. I noticed that the plug in the middle of the 12V cable as well as the inline fuse holder gets decently warm. I just checked the voltage drop from the supply side of the fuse to the positive battery terminal while charging and saw 0.3-0.4+ volts of loss. Not sure how much voltage was lost through the plug since there was way I could have tested it, but as warm as it got it was likely another few tenths of a volt.

Anyways, I cut the crappy plug out and directly soldered the wires together as well as replacing the fuse holder with one without significant voltage drop and it seems to charge way better now. For the first time since I had this charger, I saw it actually charge at 7.6 amps! I do not yet know if the charger will consistently fully charge batteries now that I fixed its crappy connections, but I will be report back when I do know.

In addition to the obvious power loss, I think the voltage drops were causing the charger to not accurately sense the battery's voltage and making the charger think the battery is more charged than it actually is. If the charger thinks the battery's voltage is significantly higher than it actually is, that obviously could cause problems.
 
Fixing the poor connections on the Noco's 12V cables definitely did help with the issue of not charging completely and indicating 100% charge too early, but didn't fix it entirely. But it did drastically reduced the charging time since it now actually produces its rated output until the battery reaches around 13.8 volts, so that's nice.

I'm tempted to replace the stock ~18 gauge cables with 12 gauge to further reduce the voltage drop. 5 feet of 18 gauge copper wire carrying 7.6 amps will lose around 0.5 volts, which is still pretty significant. 3 feet of 12 gauge wire (what I would use) would lose less than 0.1 volts, which is much better.

My only concern is if the charger was intentionally designed to produce extra voltage to compensate for the voltage drop of the stock cables, the charging algorithm could be adversely affected and the battery may receive too much voltage if the wiring didn't drop as much voltage as the charger expects since it only knows the voltage at its end of the cables, not at the battery. Is this something to worry about or is it a non issue?
 
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