24V system batteries sucking

[Diesel42]

I have the same system as Eric but use a "Battery Minder"(Automotive Battery Chargers | Battery Chargers by BatteryMINDers.com).

Supposed to be a charger/desulfater. Sulfation is what is what kills a battery. I have permanent quick connect leads on my low side battery that extends through my grill. The solar converter keeps both balanced. Since I completed this system(solar converter,12v battery minder,two red tops) I have never had problems since.

 

[Eric Winkworth]

Does the battery minder you have do the 3 stage smart charging process? I was looking at those some nice units but $$$...

I failed to mention also my batteries seem to be much more happy now then prior to my installation of the solar setup... Still though I found so many sketchy connections and really rough electrical work (some of it I know for a fact was done by toyota mechanics).

I think 5 years is a fair time to get out of batteries in a 24v setup though, much longer then my experience without the solar setup, although I had evil taps...

cheers

 

[markthemenace]

I will just move the converter to the switched part of the truck harness. A 12V zener diode on the radio memory terminal will be plenty to keep it alive.

I still don't grasp why a small constant load will cause one battery to drain... but I suppose thats just an old battery phenomenon.

Could you elaborate on this zenier diode thing? I've got my converter on switched mode only, so the radio presets are never saved. This is a constant irritation for the wife, and I can't figure out how to fix it.

 

[amaurer]

Could you elaborate on this zenier diode thing? I've got my converter on switched mode only, so the radio presets are never saved. This is a constant irritation for the wife, and I can't figure out how to fix it.

1N4742A 12V Zener Diode - RadioShack.com

$2

You'll need a 1k resistor, run it from +24V to your radio's memory line (the one the instruction say to hook to a constant power source). Then run the zener between the same memory line and ground - the zener will have a stripe on it, orient the diode so the stripe points at the memory terminal and the unstriped end goes to ground.

The zener will leak about 25mA which will drain your battery in ~4000 hours or so. Should be fine.

Or...

RadioShack® +12V Fixed-Voltage Regulator 7812 - RadioShack.com

Also $2

That guy will do the same thing - hook one pin to +24V, one pin to Gnd, and the middle pin to the radio terminal. Done.

That'll only suck about 5mA, I guess its the better option.

 

[amaurer]

Oh, also, batteries dead again this morning.

I'll buy new ones at lunch, had to drive the 42 today.

 

[markthemenace]

Sorry to hear about your batteries! Thanks for the tip on the RS regulator. Seems like a real simple fix to a (literally) nagging problem

 

[FF LC FREAK]

had to drive the 42 today.

C'mon, rephrase that! You GOT to drive the 42 today! What an opportunity!!

By the way, that's good info for the radio. I was wondering how I was going to hook up the radio in my 42 to keep the presets. I have a coverter, but it is switched, so it only comes on when I turn the key. Thanks for that!

 

[Diesel42]

Does the battery minder you have do the 3 stage smart charging process? I was looking at those some nice units but $$$...

I failed to mention also my batteries seem to be much more happy now then prior to my installation of the solar setup... Still though I found so many sketchy connections and really rough electrical work (some of it I know for a fact was done by toyota mechanics).

I think 5 years is a fair time to get out of batteries in a 24v setup though, much longer then my experience without the solar setup, although I had evil taps...

cheers

Yes it's the 3-stage smart charger that puts a pulse based on charging algorithms that's supposed to break that sulfation up on the plates?????? All foreign to me but it solved all my battery issues so I guess it works. You are right, the small charger was about $40.. and the larger was $120.00 or so.

 

[Freewheel]

I think I would be careful about the 1 amp regulator or the zener diode idea. In most of the car stereos that I have seen, the "memory wire" that gets hooked up to constant current also runs the main power for the stereo. The thin wire that goes to the ignition switched current is just a control wire. That means that when you crank the stereo up and it draws 10 amps, that little regulator turns red hot and goes pop.

This is the main pita of the 24 volt truck and stereo thing. I was looking today online at the Jensen 3620B Heavy Duty stereo which has a 30 day memory with an internal battery. I'm actually thinking of replacing my Alpine deck with the Jensen, mainly for that one feature...

 

[amaurer]

I think I would be careful about the 1 amp regulator or the zener diode idea. In most of the car stereos that I have seen, the "memory wire" that gets hooked up to constant current also runs the main power for the stereo. The thin wire that goes to the ignition switched current is just a control wire. That means that when you crank the stereo up and it draws 10 amps, that little regulator turns red hot and goes pop.

This is the main pita of the 24 volt truck and stereo thing. I was looking today online at the Jensen 3620B Heavy Duty stereo which has a 30 day memory with an internal battery. I'm actually thinking of replacing my Alpine deck with the Jensen, mainly for that one feature...

I wonder if what you say is true. I would have expected them to be designed the other way.

I'll experiment and report back.

 

[Ron R]

The radio/cd player I have only has one wire. Has to be powered all the time to keep memory alive.
So I build a simple contraption to solve the "converter is drawing my battery" problem.
I think the solution of just using an Zenerdiode or just a voltage regulator on its own (oscillation might occur) is a thad too simple.
My setup very simple and maybe not a "clever design" but I'm using it for several years now without any problem.
Maybe you can adapt it for your needs. You can find it in THIS thread, posting nr 19. I've posted a diagram there.

 

[bj40green]

The radio/cd player I have only has one wire. Has to be powered all the time to keep memory alive.
So I build a simple contraption to solve the "converter is drawing my battery" problem.
I think the solution of just using an Zenerdiode or just a voltage regulator on its own (oscillation might occur) is a thad too simple.
My setup very simple and maybe not a "clever design" but I'm using it for several years now without any problem.
Maybe you can adapt it for your needs. You can find it in THIS thread, posting nr 19. I've posted a diagram there.

Hi Ron,
I saw your diagram with the LM7812 in your other posting.
I understand the diagram but I have a question:
What happens when the truck/converter is "off" and I switch on the radio? I think the radio is fed by the LM7812 regulator. So if it's a powerfull radio, say 2x 40W what happens?

Rudi

 

[Ron R]

Hi Rudi.
Good question....doesn't do anything and I cannot explain it.
The radio/cd player was a very veryyyyy cheap unit (around 45 euro, say 35 USD - it was discounted) and had no documentation of any importance so I cannot look into a diagram.
All I can come up with is that, because of the diode in the line, the radio senses that the voltage is low (just over 11V) and doesn't switch on. It's sufficient tho to keep the memory alive.
The radio/player also switches off when the converter is switched off (starter switch "off" ) I don't have to switch it off by hand.
I remember at the time I installed the radio (six, eight (?)) years ago I was wondering how this would work.
The converter actually delivers a voltage around 13.8 volt, resulting in a voltage for the radio of more than 13V despite the diode in the line to the radio.
I found out that this diode was necessary to make things work. If this diode was left out, the converter was acting strange due to the voltage provided by the voltage regulator.

Depending on the type of radio there are several possibilities. I know of radios that use a separate line switched to the IGN/ACC circuit to switch ON and OFF and have a main feed to the radio to provide the neccessary current which just feeds the memory when OFF.
But there are also radios that have a constant power line to feed the memory all the time and are switched off and on by the main feed to a switched line.
And there is this strange setup I have.....
Depending on the conditions you can use the 7812 separately to feed the 'memory' line. Just connect the line that runs to the main feed in my diagram to the memory line and not to the main feed. Do not forget to include the diode and capacitors. The capacitors are essential to avoid possible oscillation of the voltageregulator.

 

[eleblanc]

Batteries are 5 years old.

IMO replace them, 5 years fighting each other to get balance, it is a long fight, they are tired

I've changed battery many times and i've settle for good deep charge marine batteries. Been having them for 2 years now. My converter will drain them dead, since i rarely use the truck, but i have a 6 amp marine charger that will bring them back to life from a complete dead state.

 

[bj40green]

Hi Rudi.
Good question....doesn't do anything and I cannot explain it.
......All I can come up with is that, because of the diode in the line, the radio senses that the voltage is low (just over 11V) and doesn't switch on. It's sufficient tho to keep the memory alive.
The radio/player also switches off when the converter is switched off (starter switch "off" ) I don't have to switch it off by hand..............

Hi Ron,
Thanks for the explanation.
So the lucky factor in your case is that the radio has a cut off point under 12V i.e. it won't switch on. Lucky you!

Rudi
(groeten uit een warm en zonnig Costa Rica)

 

[Ron R]

Off topic...sorry gents, we have to talk dutch for a minute

Rudi
(groeten uit een warm en zonnig Costa Rica)

Zit jij er beter bij dan wij. Afgelopen dagen dikke mist en koud, vandaag gaat het wel weer.
Hoe kom je in Costa Rica terecht? Genoeg van het Nederlandse klimaat? (letterlijk en / of figuurlijk )

Groeten, Ron

 

[amaurer]

Got new batteries.

 

[eleblanc]

Got new batteries.

What did you get!

 

[amaurer]

Nothing fancy - Costco batteries. If I have to replace them every 5 years then I'll be happy to do so for free.

 

[Eric Winkworth]

I'm pretty sure they're made by Johnson Control's same company that makes Interstate... They're good batteries and costco is even better then walmart for taking things back. We had a 2 year old BBQ from there that the element rotted out on and couldn't source a replacement, when I went in to talk to them about it, they ended up taking it back with a full refund! I couldn't believe it...