RV starting battery maintainer?

[PNW_Steve]

Hello All,

I am hunting for a solar battery maintainer for the 12 volt starting/coach batteries on my RV.

I have 3 - Group 31 batteries and currently disconnect the battery cable when not in use and then periodically charge the batteries and connect the cable and start the bus.

I would like to have a solar float charger that will treat my batteries well and allow me to leave them connected between uses.

Can you all recommend a particular brand or model? I have been looking online and cannot discern between the gold and the garbage.

What do you all recommend?

Thanks.

S.

[PNW_Steve]

Any thoughts on this one: http://products.batterytender.com/So...ontroller.html

[Sunking]

Steve your best bet is to use an AC powered float charger. Using solar will just age your batteries faster and cut cycle life. Every stinking day the solar controller will cycle and go through a full Abbsorb charge cycle on a fully charged batteries over charging them and burning up water and the plates. Is that what you had in mind?

[littleharbor]

If you can eliminate any parasitic loads your batteries will be better off for it. The Smoke ,Carbon Monoxide and/or propane detectors as well as any clocks will cause your battery to cycle. I found the fuses in the power center and pulled them. I leave the Power center door open to remind me to replace these fuses before hitting the road.

[Mike90250]

Maybe the 10w maintainer panel that sits on dashboard and plugs into cigar lighter to keep the battery alive would work. 10W is not too much for 300ah of battery

[PNW_Steve]

Steve your best bet is to use an AC powered float charger. Using solar will just age your batteries faster and cut cycle life. Every stinking day the solar controller will cycle and go through a full Abbsorb charge cycle on a fully charged batteries over charging them and burning up water and the plates. Is that what you had in mind?

No. I want to care for my batteries.

Unfortunately, there is not full time utility power in the location that it is parked.

The only parasitic load is the ECM. To keep it from discharging the batteries I have to disconnect the coach batteries. That is what I have been doing.

Is there any solar float charging solution that you would recommend?

[PNjunction]

Yes - the BatteryMinder SCC-180.

One of the few manufacturers that have information teaching users how to use hydrometers with floodies, or with agm, do limited voltage measurements, and waiting the appropriate amount of time for testing. While not as good as the info you find here, it is FAR more valuable to the average consumer that wants to know just a little bit more.

Also, one of the few manufacturers that *specify* that while yes, this will charge, it is primarily a maintainer, and not a full fledge charger, which you already have. They suggest that one maintains the batteries after you have properly charged them first with an AC supply.

That kind of honesty is hard to find.

The SCC-180 controller can be had with their own panels as kits, or you can use your own panel if the SCC-180 is bought individually. Although they say it can handle up to 180w of solar input, in reality, I wouldn't push it past 150. Of course, smaller panels can be used, just be mindful that super small panels won't have enough oomph to really maintain big banks.

It comes with an "led monitor", which I threw away, since I like to use my own voltmeters instead of a limited dummy-gauge. But it comes with it for the uneducated consumer. And oh yeah, a temp sensor, which you can remote with an accessory if you want more than just ambient temp-comp. These guys are serious.

If you need to maintain more than just this set, they also have various *fused* splitter accessories and so forth. Perhaps read their manuals online to get a feeling for it.

You may ignore the "pulse" desulfation if you like. The fact is, that underneath is a damn fine *maintainer* for those who know that a PROPER charge from an AC unit is how you start off on the right foot. It is conservative enough not to overcharge most batteries - which is the reason they emphasize starting off on the right foot initially.

That being said, I have recommended it to a few RV friends that weren't really interested in battery maintenance, and it has worked to save a lot of frustration on their part. With a bit more knowledge, they'd be even further ahead, which sounds like your category.

Highly recommended for what you want to do - but be mindful that the panel input connectors are kind of small, but workable with most small to medium gauge wire.

The main reason I recommend it, is that it works well enough, albeit slightly conservative in nature (unless you want to get into the pulse stuff, which I'll leave out), and has NO adjustments to get right or wrong. Thus you can use it on all your lead-acids and not worry if you read the right material in the forums here with more DIY componentry.

I'm assuming you have all your group 31's in parallel, but perhaps not. Depending on what you are doing, you may be able to get by with a smaller panel for *maintenance* - although yes, the SCC-180 will also charge - but as BM says, use of an ac-powered charger made specifically for your battery type is what one should start out with and use once in a while. Honesty made me buy one, and I'm happy with mine for it's intended purpose.

[Sunking]

Is there any solar float charging solution that you would recommend?

Actually there are a few solar solutions, you just have to think outside the box. Many charge controllers allow you to set Bulk,Absorb, and Float voltages via software. Bulk, Absorb, and Float are just words without any real meaning, and in fact, are just voltage set points and nothing more or less. Float like Absorb is just a voltage set point, and Float Voltage on a 12 volt battery is between 13.2 and 13.8 volts depending on battery manufacture. So if you have a CC that you can set the voltages you simply set Bulk = Absorb = Float = 13.2 to 13.8 volts.

[PNW_Steve]

Thank you!