Battery question

[OldCoot]

Originally Posted by Deemar

If you want extra power, and are concerned about using two batteries, consider two IDENTICAL 6 volt batteries in series. Being identical and in series, they will see the same charging and discharging current for most of their useful life. One will eventually deteriorate before the other, but by that time you'd be looking at new batteries anyway. And being in series, you don't need to be concerned with them interacting or discharging each other. Beyond that, follow all the advice about deep cycle not cranking batteries etc. And most often you get what you pay for, premium performance usually comes at a premium price.

Only problem is using 6v batteries is if one goes bad, you are SOL. No so if using 2 12v. One goes bad, you still have one.

[Blackhat6mike]

Originally Posted by OldCoot

Only problem is using 6v batteries is if one goes bad, you are SOL. No so if using 2 12v. One goes bad, you still have one.

OldCoot X2.
Also, two 6volt batteries take up more space and weigh much more than 1 12volt.
I have 10 6volt batteries in my sailboat for the house bank and 1 12volt for a cranking battery. If there was any way to replace those 6 volt units with 12 volt batteries, I would do it tomorrow, but it seems the boat was built around using the 6 volt EV batteries. EVs [electric vehicle] are taller than regular golf cart bats and cost big time, but seem to last forever. Per the same footprint, I could get a lot more amp hrs using 12 volt bats.

[Deemar]

Originally Posted by OldCoot

Only problem is using 6v batteries is if one goes bad, you are SOL. No so if using 2 12v. One goes bad, you still have one.

OldCoot, you are absolutely correct. Even the best battery manufacturer has a non-zero defect rate, and all sorts of things can happen in the bush.

There are many solutions that fit different situations and comfort levels. If those batteries were needed to start a motor home and drive it away, then two 12's would be a good safety net for sure. Same for winter camping where a functional electrical system may mean avoiding hypothermia. In my case, I have a camper and a tow vehicle with an oversize battery. Both have solar panels and the camper has 2 auxiliary 12 volt 66 AH gel cell batteries for running amateur radio equipment. I would be comfortable with two good quality 6 volt batteries running the camper because I have so many options to work around a failure, including going without power in the trailer. But again, you are quite correct, most people don't have those options so two 12's provide the possibility of getting by with one if the other fails.

[Garrette]

Originally Posted by mud yapster

Here's what you can do to supply power to your RV for a long long long time or forever until the batteries are dead or worn out.
Here's my battery bank.

3/12volt AGM 435ah battery bank. The 8 gauge smaller black and red wires are from my 520 watts of solar panels Morningstar MPPT 60 amp charge controller system charging the battery bank. The 2 light blue wires feed over to the Cummins Onan Generator to start it, and the big ones 2/0 gauge feeding the 300 amp fuse feed to my 2000 watt inverter/transfer switch to supply my microwave, coffee maker, 3 flat screen TV's, and anything else on my RV that needs 120v. The 2 2gauge medium size red and black wires feed the 12volts to the 12 volt side of my 5er.

Hope this gives you an idea how easy you can supply unlimited power to your rig. Money and weight of the system will be your only limitations.

I have but yet to install a progressive 9160 charger for my Sunseeker. Is this ok for the vmax batteries? I want AGM's What charger do you have installed? I just want a good system for the long haul. I do not boondock longer than 2 nights. Any advice on my simple needs


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[pgandw]

Originally Posted by OldCoot

Only problem is using 6v batteries is if one goes bad, you are SOL. No so if using 2 12v. One goes bad, you still have one.

On the other hand, using 12V batteries in parallel can lead to nasty problems, too (as I found out).

Unbeknowst to me, the 30 amp fuse for the battery charging had been blown in my converter. So my two 12V batteries had been discharged to 11.5 volts (I didn't realize this) when I disconnected both the trailer and 2nd battery positive leads from batt #1 (my standard practice during storage).

Hooked up my reliable 10 amp Sears/Schumacher 10 amp charger 2 weeks ago in our new house. Circuit breaker on the charger kept tripping due to overload. Disconnected the batteries from each other, and commenced charging #1 battery.

Without thinking (a major problem of mine), decided to link up batt #2 a couple of days ago. The 6 gauge link wires turned cherry red and ignited the boiling off-gassing at the vent from batt #2. Managed to get the plug pulled on the charger and cut the link wires with wire cutters before fire spread. Link wires (and probably batteries) destroyed.

After the fact analysis: if two normally paralleled batteries get to dissimilar charge states independently, there will be incredible (fire-starting) current and off-gassing if any attempt is made to parallel them prior to getting charge states equalized. In other words, moving one of those 2 battery selector switches between the both and individual battery positions without knowing the battery voltages are the same is an invitation to a similar event.

PS: The good news about the new house is that I can actually fully setup the A-frame inside the garage. Bad news is spending the $$ on new batteries.

tired of my own SPUT (Stupid PopUp Tricks) - I want to learn from others
Fred W
2014 Rockwood A122
2008 Hyundai Entourage
camping Colorado and adjacent states one weekend at a time
next trip Lincoln, NE for Cornhusker football

[Deemar]

pgandw, sorry to hear about your experience with cherry red cables. I'm very glad to hear that it didn't turn out any worse!

[Blackhat6mike]

Doesn't anyone fuse their battery systems? I have a ANL fuses into and out of my inverter wiring, battery cables, converter system, etc. Cheap insurance and you won't be starting fires or blowing things up. Even the fans for venting the battery compartment are fused.

[Bluepill]

Originally Posted by Blackhat6mike

Doesn't anyone fuse their battery systems? I have a ANL fuses into and out of my inverter wiring, battery cables, converter system, etc. Cheap insurance and you won't be starting fires or blowing things up. Even the fans for venting the battery compartment are fused.

Yes, proper fusing is always a good idea. However, I have never seen fusing in cables between parallel-connected batteries. Not that it couldn't or shouldn't be done.

In the unusual case above it would have helped.

[Blackhat6mike]

Not between each battery, but between the inverter and battery bank and between the batteries and house. I'm on solar and that system is fused [breakers] coming in and going out. My entire bank runs the house and the inverter since the solar system keeps it up. One battery can be switched out just for house if need be.
Being an electronics tech, fuses are part of my DNA.