advice for maintaining batteries off grid..

[jjwelly]

Hello Everyone. I have been trying to figure out the best way I can keep my 12V batteries from pooping out so fast on equipment that sits. Seems like I have to replace every battery every year. Some of my equipment is stored at my house, where I have power, then I have other equipment that is stored at a piece of property without juice. There are three batteries at the offsite location that I'm wanting to maintain. 1st is a bobcat battery, 12V group 24 600 CCA, 2nd is a John Deere lawn mower, 12V U1R 230 CCA, and 3rd is a Kawasaki 650 quad, 12V AGM 220 CCA. First question I have is...When a battery has sat so long to get down to 9.29V, is it ever possible to get it back, or is it toast? Seems like they won't hold a charge and I just get new ones like every year, or two at the most. Second question, and more important, what options do you all feel would make most sense to maintain these offsite batteries? I've been looking at the 5-6 Watt solar trickle chargers selling for $40-50 bucks thinking I could just buy 3 of them if they work to maintain, or I've also seen the BatteryMinder scc 015 that claims to be able to maintain up to 4 batteries in one unit, but it runs $150. Before I went any further, I ran into this forum and wanted to get some real knowledge from you all with hopes of you pointing me in the right direction. Any info is greatly appreciated. Thank you...

[solar pete]

Howdy jjwelly and welcome to Solar Panel Talk. I am no expert on batteries but for memory 9.29 v = toast. I think you are on the right track looking into battery maintainers, some of the more knowledgeable folks will hopefully chime in, cheers.

[jjwelly]

thank you for your response. I figured my batteries are all bad and need replacing. Getting pretty expensive replacing them all every year/other year, so I need to change something I'm doing. My boat batteries are always plugged into my onboard charger/tender, and they last many years, so I'm sure I need to get all of my batteries on some sort of similar setup or at least some schedule where they are hooked up. And I'm sure getting the batteries out of freezing temps in the winter would be ideal, but hard to do especially with the ones that are offgrid and off site.

[bcroe]

Hello Everyone. I have been trying to figure out the best way I can keep my 12V batteries from pooping out so fast on equipment that sits. Seems like I have to replace every battery every year. Some of my equipment is stored at my house, where I have power, then I have other equipment that is stored at a piece of property without juice. There are three batteries at the offsite location that I'm wanting to maintain. 1st is a bobcat battery, 12V group 24 600 CCA, 2nd is a John Deere lawn mower, 12V U1R 230 CCA, and 3rd is a Kawasaki 650 quad, 12V AGM 220 CCA. First question I have is...When a battery has sat so long to get down to 9.29V, is it ever possible to get it back, or is it toast? Seems like they won't hold a charge and I just get new ones like every year, or two at the most. Second question, and more important, what options do you all feel would make most sense to maintain these offsite batteries? I've been looking at the 5-6 Watt solar trickle chargers selling for $40-50 bucks thinking I could just buy 3 of them if they work to maintain, or I've also seen the BatteryMinder scc 015 that claims to be able to maintain up to 4 batteries in one unit, but it runs $150.

I used to have that problem for half a dozen 12V batteries esp over winter. I connected a $5 Horrible Fright maintainer to each
battery and cured the problem. Just don't knock the plug out, or it will run the battery down. Without AC, solar is possible,
but it will likely take a much larger panel than those tiny lighter plug ins. Bruce Roe

[Mike90250]

The 5-10W solar battery maintainer panels will usually do a good job of keeping batteries topped off. Some brands use lighter plugs, some have hippo clips for battery posts.

[PNjunction]

Hi jjwelly - funny you should mention this since I was about to review the Noco 2.5/5w solar trickle chargers later on. For your purposes, don't even think of using these at this point! (lurkers - don't EVEN think of using these without the optional GCC-027 inline regulator - or wait for the review!)

Just know up front that if you are serious about keeping your batteries in shape, it is going to cost a bit up front - which might be paid off later by not having to buy batteries so often, so keep that in mind.

There are three batteries at the offsite location that I'm wanting to maintain. 1st is a bobcat battery, 12V group 24 600 CCA, 2nd is a John Deere lawn mower, 12V U1R 230 CCA, and 3rd is a Kawasaki 650 quad, 12V AGM 220 CCA.

Let's break this up into TWO things necessary. CHARGING TO FULL, and THEN maintaining. If you don't charge to full first, a maintainer will only keep the battery in the state it found it - and if that state is only half-charged, then eventually even with a maintainer, it will die. Many don't realize this mistake of not charging to full first.

WARNING!! Putting even one of those little units like the NoCo's 2.5/5w tricklers without any sort of charge controller will KILL good batteries! That's the trick - most people don't have a full charge so the maintainers won't actually harm the battery. BUT for the 1% of people that DO start out with a full charge, and then put these unregulated panels on them - bad times!

See this for reference about the perils of even small unregulated panels:

https://www.youtube.com/watch?v=z5RtZe9AW2E

For charging to full, and with your needs, I can heartily recommend the Tecmate-Optimate 6 Model TM-181. This will actually charge, and might possibly revive your low-voltage battery. Maybe, depending on how bad it is. There are many other great chargers out there, and Battery Minder has some of the most exacting, but if you aren't well up on what your various battery needs are (like absorb voltage, float voltage etc), then choosing the wrong model of Battery Minder (or any other charger) could lead to wasted money on a battery that doesn't get fully charged.

The Tecmate-Optimate 6 uses a different way of determining when a battery is fully charged, and thus there are no buttons or decisions for the end user to figure out. It is not your bog-standard cc/cv charger.

This charger should be taken to all of your batteries. Note that the Optimate 6 will also do a great job of maintaining after a full charge has finished, but with so many batteries on hand you may want to free it up for regular charging maintenance, and pick up a dedicated maintainer.

For that purpose of maintaining after a full charge has been achieved, then the smaller Tecmate-Optimate 2 Model TM-421 could be purchased for each battery you have sitting around - aside from the Optimate 6 which if you aren't rotating it around for charging purposes, will do just fine as a maintainer too....

Told ya' it was going to cost you. But if you want to do it right, this is how you do it. OH, and about maintaining multiple batteries at the same time - they ALL have to be charged to full, and quite frankly, is a trick pony better served by using individual maintainer units on each battery.

SOLAR charging. The Battery Minder SCC-015 is actually a good unit for maintenance purposes - and this one has no adjustments to make either, unlike their extensive ac charger line. Comes with a 15 watt panel which would be about the minimum I'd recommend. They have a smaller "5 watt" 005 version - skip that version - too small. If you have your own panel, you can buy just the regulator if you like.

STILL, each of those batteries in the field needs to be brought home, and given a full charge on the Optimate 6 at least once, before attaching the Battery Minder SCC-015. Even BM's own documentation warns about just plopping one of their maintainers on a battery that has not been fully charged first for best results.

I know this seems like a lot - but if you are serious about your batteries, it will cost a bit up front.

[jjwelly]

thanks everyone for the input. I guess I should consider the difference between charging and maintaining. I suppose I was thinking, apparently incorrectly, that my equipment would be charging them while running via their alternators and thus would for the most part be full after running, and thus would only need maintaining. I admit I don't really know if this is or is not the case. I know my boat trolling motor receives no charging while running, but my boat has an onboard charger/maintainer for both starting and trolling batteries. I also have a battery tender which I rotate around my various batteries at home. I also have an awesome battery charger (Revolectrix Cellpro powerlab 6) that I use for RC Lipo batteries, but it can charge Pb and other various battery types, so I might look into its capabilities some, but I doubt it would do as good as a job as the Tecmate Optimate 6, which I am ok with buying it if it does truly charge to optimal condition. As for maintaining, I will focus on each battery having its own trickler and not worry about multi units. For the remote items, sure don't want to spend the bucks for a SCC-015 for each battery. At that point, I'd almost rather bring home the batteries with me every time and have cheaper AC units maintain at home, with either my existing tender or the Tecmate 2's suggested. But really don't want to remove the batteries each time!

[jjwelly]

I was thinking about my existing charger, which has a few nice features. Mainly it operates on DC, so I can actually take it to my remote batteries, power it with my truck (while running of course), and charge them all up easily. It just does basic charging, but the current is adjustable. Just no 'desulphating' or special rejuvinating settings. So it may have it's place. I am seriously considering buying the Tecmate 6 now, and praying it can possibly 'save' some of my batteries from replacement. Two of my batteries are in trouble, and not looking good. Wish I knew how effective this unit is with 'fixing' neglected batteries.

[PNjunction]

Ok, if you are comfortable with programming the PL6, then that makes an OK dc-dc charger. Thing is, does it properly drop to float afterwards for at least 8 hours? Are you running the correct absorb and float voltages for your various batteries? Note too that Optimate has an orange dc-dc charger (Model TM-500), but that is only 2A.

Is the PL6's absorb adjustable - ie, will it be dropping to float too soon? These are the kinds of things that the Optimate 6 takes care of for you. Myself, I have a rockin' iCharger 306B for various duties, yet I still use other chargers for lead acid.

Thing is, with sealed VRLA's like agm's and gels, we need 8-12 hours of float to actually finish a charge. However, the Optimate 6 stops after absorb is finished to do a 12 hour voltage drop test. If it passes, THEN it will proceed to a float charge, and then using a 50% duty cycle (30m on, 30m off). Soooo ... to truly finish with the '6, you are looking at like 48 hours after the charging led turns SOLID green. Something to keep in mind.

Fixing a neglected battery: If you are resting under 10v with a lead-acid, it is questionable if one should even try to revive the battery. The Optimate WILL try, but it can't fix bad physical or chemical problems. Sulfation isn't the only problem. If you don't get to a deeply discharged battery in time, the electrolyte is mostly water at that point, and now you have metallic compounds sitting in water. Grid corrosion takes place, along with possible shorting dendrite growth. Sulfation grows and enlarges and can distort the plates badly.

What I'm trying to say here is that merely desulfating a neglected battery is only ONE of the problems that can occur, and in my own case, I've found that reviving a neglected battery usually just results in a poorly performing zombie. IF you get to the battery ASAP, you might be able to recover, but it will never be the same. It merely buys you some time to get your replacement in hand and treat that one right.

Re your remote use and not wanting to remove the batteries to bring home. Understandable. The KEY issue here is to get your batteries fully charged in the first place, and then hope the Bobcat or whatever else you run is run long enough to recharge it. Sulfation will still be taking place, but can be manageable with a higher-powered solar charger (WITH a controller!).

In this case, you just do the best you can do. Every once in a while, say maybe on a weekly basis - Friday night perhaps, drag your dc-dc charger out there with a larger fully charged battery, and let your bobcat's battery charge all weekend. Drag the source battery home on Monday and recharge. At least this way you only have to handle the source battery, and not be taking apart your field gear all the time.

Whew - when all this is taken into account, maybe it IS a break-even point for maintenance and just buying batteries more often is a more practical solution! You'll have to make that decision.

[jjwelly]

Thank you, thank you. Well, first off, I went ahead and ordered a Optimate 6. No matter what I do, having a great charger/conditioner/maintainer is good for me to have. Money well spent. While I love my PL6, it's, as you know, meant for other duties, like your iCharger, which rocks! I really only have two 'at home' batteries that sit. A car battery in my hot rod 88 Mustang, and a battery in my popup, which is one that needs to be revived/replaced. Also have my boat batteries here, but as I mentioned, the onboard charger/maintainer has proven itself to me over the years. So, I guess I'll plan on charging batteries with the Optimate, and then using it as a maintainer on one of the two batteries, and then sticking my battery tender plus on the other one. As far as the 3 batteries in my off site location, I guess I'll have to compromise some. Unfortunately, I can only get out there about 1/month, and sometimes can't stay but a few hours. I really don't want to buy 3 SCC-015 for $150 each to act as maintainers on them. So maybe I'll just plan to run them monthly at minimum, charge them as I can with my PL6, and bring them home during the winter months where I can keep them in 40+ degree temps and treat them with the Optimate and throw something like battery tender juniors on them.

As for trying to revive the bobcat battery which is at 9.29V, and the popup battery which is undetermined at the current moment, I think I may just replace them and plan to try my best with the replacements to keep them going best I can.

Again I REALLY appreciate the input and assistance.

[PNjunction]

Sounds good - just know that Battery Tenders brand float near 13.2v. That will void the warranty on an Odyssey agm being too low in voltage - and they are sticklers about that.

We know that it takes at least 8-12 minimum at 13.6v to actually finish the job, no matter how fast you do absorb, so the best bet is to let your Optimate 6 charge, do it's 12 hour test automatically, and then at least another 12-24 hours of float after the led goes SOLID green, since it has a 50% duty cycle in float. THEN place your BT's on the battery you wish to maintain.

If you place the BT's on too soon, they may not get fully charged, and just maintained in a 99.5% state, which is what Odyssey's beef seems to be about being walked down over time. Plenty of BT vs Odyssey float voltage material out there so I won't bring out the drama here.

[littleharbor]

I noticed you said your popup battery is the one that needs to be revived/replaced. When not in use is your popup indoors or out? There are parasitic systems in RVs like co2 sensors and smoke alarms that are battery killers if you allow the RV to sit unused for any length of time. If the popup is outdoors and in the sun you can mount a solar panel and charge controller in the roof which will keep your battery topped off and happy between camping trips. There is usually a channel in the canvas that carries the wiring for the overhead lights. You can fish the wire from the solar panel through this and on to your charge controller location. I have done this many times on friends popups. If you mount enough solar on the roof you are set for dry camping as well.

[jjwelly]

The popup currently is stored at my house outside. I do know that there's at least a smoke alarm or some sort of alarm that does pull power when the battery is connected. There's a fuse that I just yank when not in use so there's no draw on the battery. Since this is stored with juice available, I'm going to put an optimate 2 on it. I have since bought an optimate 6 as well as 3 optimate 2's as suggested by PNjunction. However I do foresee the popup possibly joining my other equipment offsite where power is not available. (bobcat, 4 wheeler, and lawn tractor). Seems like there's not a good option solar for these items.

[littleharbor]

"Seems like there's not a good option solar for these items"
Not sure what you mean by this? You could use a small 40 watt panel for maintenance charging or go up to a 120 or larger panel for dry camping. I have done many pop up installs with great success.

[jjwelly]

Well, i'm not very knowledgeable on solar panels, charge controllers, etc, but when you say i can use a 40 W panel and charge controller, is that setup good for only 1 battery? I have 4 batteries, and if the cost of this 40 watt panel is where I think it is, and if I would have to have one per/battery, sure doesn't make sense to me. Help me understand the equipment needs and costs associated with setting something like this up.