Optima Red Top vs. Yellow top
- Thread starter CLynn85
- Start date
njtaco
Explorer
Sorta Hijack...
As to not start a new thread...
I just got a Odyssey PC1200MJT for the 03 Tacoma. :victory: I intend this to "do it all" until a second battery comes around. The battery I am replacing came with the truck, and is cranking noticeably slower below 30 deg in the mornings.
We use a Peltier effect 12V cooler, about 4 continuous amps, when camping. I unplug at night, or adapt to 110V when available (infrequently). At 44AH, the battery should last 10+ hours if I am away from the truck/not driving. We usually drive somewhere each day. :truck:
Question is this...I know I should not use the AGM in conjunction with an old wet cell, and can't afford a second AGM right now. In keeping with the 'spend money once' theme, considering a jump-pack as a stop-gap seems wrong, and I feel I should just wait and get a second battery. Can I use an Optima (Spiral cell) Red Top up front, and the Odyssey (AGM) as an aux battery, or are they incompatible? I think I can save $ with the Red Top. Or will the single AGM suit me? I don't go so far away that help is impossible to find, and my very life will not be at risk over a dead battery. Along the same lines, will mixing an Odyssey 1200 and an Odyssey 680 be a problem? I could afford the 680 more easily, but could wait for the 1200 if I have to...I would probably use the 680 as an emergency start battery only.
A permanent winch is not in the near future, but if it were, the 1200 would be the battery it will be wired to, regardless of the other decisions.
Another thought...when installing a new wet cell battery, it should be topped off with a slow charge before use. Is this the case with an AGM battery? I'm doing it anyways, but I am curious if it is needed.
Just throwing it all out there, if this post should be elsewhere, please feel free to move it...
Thanks,
Bob
As to not start a new thread...
I just got a Odyssey PC1200MJT for the 03 Tacoma. :victory: I intend this to "do it all" until a second battery comes around. The battery I am replacing came with the truck, and is cranking noticeably slower below 30 deg in the mornings.
We use a Peltier effect 12V cooler, about 4 continuous amps, when camping. I unplug at night, or adapt to 110V when available (infrequently). At 44AH, the battery should last 10+ hours if I am away from the truck/not driving. We usually drive somewhere each day. :truck:
Question is this...I know I should not use the AGM in conjunction with an old wet cell, and can't afford a second AGM right now. In keeping with the 'spend money once' theme, considering a jump-pack as a stop-gap seems wrong, and I feel I should just wait and get a second battery. Can I use an Optima (Spiral cell) Red Top up front, and the Odyssey (AGM) as an aux battery, or are they incompatible? I think I can save $ with the Red Top. Or will the single AGM suit me? I don't go so far away that help is impossible to find, and my very life will not be at risk over a dead battery. Along the same lines, will mixing an Odyssey 1200 and an Odyssey 680 be a problem? I could afford the 680 more easily, but could wait for the 1200 if I have to...I would probably use the 680 as an emergency start battery only.
A permanent winch is not in the near future, but if it were, the 1200 would be the battery it will be wired to, regardless of the other decisions.
Another thought...when installing a new wet cell battery, it should be topped off with a slow charge before use. Is this the case with an AGM battery? I'm doing it anyways, but I am curious if it is needed.
Just throwing it all out there, if this post should be elsewhere, please feel free to
move it...Thanks,
Bob
njtaco
Explorer
asteffes said:
I intend to use either a controller like Scott has in the Ex-West Tacoma, or it's simpler brother, an ignition-on signaled continuous duty "dumb" solenoid. Either would have a diode-protected just-in-case jump-start button. Either way, they would work "as one" when the truck is running.
Amp-Hour vs draw calculations
Hello Bob:
In one of your previous posts you mention planning on getting 10 hours of a 4 amp draw from a 44 AH battery. While that may work, it might not be a good idea. I'm not an expert on batteries, but I'm pretty sure that the relationships between depth-of-discharge and number-of-cycles-before-failure is curvilinear, suggesting that you can get lots of charge cycles out of a battery if it is only moderately discharged before recharging but very few cycles if the battery is deeply discharged.
In the sailboat world, where I have more experience with batteries, the general rule of thumb is to design a system for discharge of less than 50% before fully recharging the battery banks. This seems to balance things into an effective relationship between battery longevity and battery size. Under that rule you'd be pushing your 44 AH battery about right with 5 hours of a 4 amp draw.
You also mention potential problems with mixing batteries. I think this is a more serious issue when sets of batteries spend most of their life in parallel under both charge and discharge. As asteffes mentioned when your batteries are usually isolated and only occasionally in parallel for charging you'll be basically OK. I think the problem comes from minute differences between the voltage capacity of individual cells across batteries. When in parallel for long periods the cells can't maintain equilibrium voltages due to these minute differences and thus "fight" each other, possibly causing premature battery failure.
Howard L. Snell
Hello Bob:
In one of your previous posts you mention planning on getting 10 hours of a 4 amp draw from a 44 AH battery. While that may work, it might not be a good idea. I'm not an expert on batteries, but I'm pretty sure that the relationships between depth-of-discharge and number-of-cycles-before-failure is curvilinear, suggesting that you can get lots of charge cycles out of a battery if it is only moderately discharged before recharging but very few cycles if the battery is deeply discharged.
In the sailboat world, where I have more experience with batteries, the general rule of thumb is to design a system for discharge of less than 50% before fully recharging the battery banks. This seems to balance things into an effective relationship between battery longevity and battery size. Under that rule you'd be pushing your 44 AH battery about right with 5 hours of a 4 amp draw.
You also mention potential problems with mixing batteries. I think this is a more serious issue when sets of batteries spend most of their life in parallel under both charge and discharge. As asteffes mentioned when your batteries are usually isolated and only occasionally in parallel for charging you'll be basically OK. I think the problem comes from minute differences between the voltage capacity of individual cells across batteries. When in parallel for long periods the cells can't maintain equilibrium voltages due to these minute differences and thus "fight" each other, possibly causing premature battery failure.
Howard L. Snell
njtaco
Explorer
Howard,
I've considered the down side of drawing way down the battery "bank" too. I agree with your concern 100%... I guess when I posted the single battery idea I was thinking two things: worst case scenario (for my intended use) and getting away cheap (not a good idea.) I'm really leaning toward installing a second of the same battery. I need to find a good safe place to put it, though. I have this idea, see... :Mechanic:
The issue between battery types I am not as concerned with now, I had not considered that the batteries would not be asked to "work together", just to be charged at the same time.
I also have to consider I could put the money (about $175 or so, plus solenoid, cables, etc.) toward a "real" 12V Norcold/Engel fridge ($800 or so). This would cut my power consumption nearly in half roughly, as I rarely camp in temps over 90 deg. (Wife can't tolerate the humidity.) The fridge would be in the back of the truck, in a cap, in a blanket, etc. This would give me the added benefit of more stable temps, as the 12V cooler I am using has no thermostat... it is either on or off. Less wasted food in the long run, I think.
:eatchicke
Anybody want a good deal on a 12V cooler?
I've considered the down side of drawing way down the battery "bank" too. I agree with your concern 100%... I guess when I posted the single battery idea I was thinking two things: worst case scenario (for my intended use) and getting away cheap (not a good idea.) I'm really leaning toward installing a second of the same battery. I need to find a good safe place to put it, though. I have this idea, see... :Mechanic:
The issue between battery types I am not as concerned with now, I had not considered that the batteries would not be asked to "work together", just to be charged at the same time.
I also have to consider I could put the money (about $175 or so, plus solenoid, cables, etc.) toward a "real" 12V Norcold/Engel fridge ($800 or so). This would cut my power consumption nearly in half roughly, as I rarely camp in temps over 90 deg. (Wife can't tolerate the humidity.) The fridge would be in the back of the truck, in a cap, in a blanket, etc. This would give me the added benefit of more stable temps, as the 12V cooler I am using has no thermostat... it is either on or off. Less wasted food in the long run, I think.
:eatchicke
Anybody want a good deal on a 12V cooler?
devinsixtyseven
Explorer
thanks, i did not know that...i'll give it a shot.HenryJ said:
there are two kinds of blue tops, are you thinking of the one with the bulge on the short side vs the one that's more or less rectangular? the one with the bulge is not the same as the others, i'll have to check on the difference (if any) between the yellow and blue tops...
-sean