Charging Batteries

[GreatWhite]

Finally found my 6 V batteries at Costco. Long story I started elsewhere.

My question is.. How do I charge them??? Seems pretty simple.. but after reading THIS I'm not sure I'm understanding this tonight.. must be lack of sleep.

Installed the batteries. Checked out the bank and I was at 12.35V and down $350. According to this article.. 12.35 V is about a 70+% state of charge.

At this voltage, or at any safe voltage below that, does it really make any difference if I charge at a HI amp rate or a Battery Tender rate.. ~1.5- 2 amps? Outside of time.. I know the lower rate will take MUCH longer than my supposed Schumachar Automatic Charger which has a 12A setting and a 2 Amp setting.

Help educate me. I don't want to boil the batteries and overheat them. Not sure how Automatic this Automatic charger is...

[bob109]

Here's the info you need on batteries A lot of info to digest but you'll have all the answers to your questions

The 12volt Side of Life (Part 1)

http://www.marxrv.com/12volt/12volta.htm

[GreatWhite]

No disrespect her Bob.. but, that is the article I had referenced in my post. Probably you didn't see it as a hyperlink. Thanks for taking the time to post tho. I need help clarifying this article with regards to the charging part. Guess my brain is pretty foggy tonight..

[autofish]

Does your rig have a good 3 stage inverter charger if so hook new bats up and plug in to shore power or start the gen set and let the charger go to work. If you don't have a 3 stage charger use your 12amp till you see 14.6 volt for an hr or so then switch to the 2amp setting for 24 hr. hope this helps

[garym114]

If you want to check out the Schumachar on auto put it on 12 amps and connect it to your car battery. It should decrease in just a litle while. Now that your trust it put it on the 6v's
Batteries have a date code too and if they have been sitting they will not be at a full charge.

[BryanL]

I don't know what it is but nearly every thread like this gets someone popping in with the '12v side of life' as if it solves every question. Too much is just as bad as too little, IMHO, and tends to ignore context and user starting point.

Since most RV's only come with a fixed voltage converter, the best thing you can do for your batteries is to upgrade your RV converter to one that knows about multiple stage charging and knows about battery maintenance to keep a top charge and inhibit sulfation. - a good converter is one that doesn't need your attention to either what it is doing or what it is doing to your batteries.

When you measure battery state of charge, always allow at least a half hour between any significant charging or discharging and the measurement. Avoid getting too precise. Start thinking about getting it charged when the voltage gets towards 12.2v and avoid letting it get below 12.0v. Recharge promptly and fully as a battery left sitting partially charged ages more quickly than a fully charged one.

When your battery is charging, the charging voltage should start at about 14.4v or so and drop down to 13.6v as the battery gets charged. When fully charged, which can take 12 hours, the voltage should drop down to the 13.2v to 13.4 volt range as a 'float' charge. When you disconnect the charger, the voltage will gradually settle down to 12.8v or so.

Voltages that are too high will cause electrolyte loss so if you find you need to add water to your battery more than once or twice a year, you know they are being overcharged.

Maximum charge rate for wet cell batteries is usually specified as the C/5 rate. What this means is 40 amps for a 200 AH battery (40 = 200/5) - It is very unlikely you could get this much for a typical RV situation unless the battery was drained way more than it should have been or the charging voltage was much higher than is good for the other stuff in your RV.

A good charge rate of C/20 amps or more for the first part of charging can be good to help keep the electrolyte stirred and avoid the buildup of the sulfation that ages a battery.

What usually kills RV batteries is poor storage maintenance. This means not getting a full and complete charge after an outing and then not maintaining them properly during non use. Proper storage maintenance will keep the full charge without overcharging and will also apply a sulfation inhibiting technique.

[Dave78Chief]

Greatwhite,
I have watched your battery evolution over a few threads (battery replacement, charger purchase, and now here) and here is my feedback:

1) The first thing I would do is clearly establish what charging capability your 2006 HR has. Many rigs after 2000 have either a 3 stage converter or 3 stage inverter/charger installed in them. If yours does, and it is working properly then that is all you need. The 3 stage charging algorithm in these type of units automatically and efficiently recharge "and" maintain the battery when the rig is plugged in to shore power (battery disconnect typically has to be ON for the these devices to maintain the battery).

2) If you do not already have one of those 3 stage devices, then rather than using that small, but actually way overpriced, 4 amp device you bought you should get something like one of these



Sears: Online department store featuring appliances, tools, fitness equipment and more

Manual: http://servicenet.blackanddecker.com...VEC1089ABD.pdf

or,

Amazon.com: Black & Decker BC40EWB 40 Amp High Frequency Battery Charger with Smart Interface: Automotive

Manual: http://servicenet.blackanddecker.com...12,BC40EWB.pdf

Both of those chargers provide automatic 3 stage charging and can function as a battery maintainer. Those features are the primary key components you want to have in stand alone charging system. You can find either unit in the $50 - $90 range. I have had the 40 amp model for a few years now and have been very happy with it. Before migrating to the larger 40 amp model, I had the one at the top when it was produced under the Brand name Vectra. It lasted 10 years before I finally had to replace it. It came out before 3 stage charging became the sort of defecto standard.

Again, determine what converter or inverter/charger is already in your rig and it's capabilities. Almost all new RV's already have these qualities and many since 2000 or so have had them. While write ups like the 12 Volt side of life provide you with the principles behind battery care, devices like these smart chargers and the components installed in modern RV's have many of the features built into them in order to make life easier for all concerned.

For reference, that 4 amp model you purchased is only really good for battery maintaining. Any serious recharging needs the amperage rate of these type of chargers in bulk mode. The B&D chargers also perform battery condition analysis as well as battery reconditioning.

Dave

[Francesca]

I hope nobody minds if I ask what's probably a really dumb question:
If I buy one of the smart chargers listed above, can I use the 12v lights in my trailer while the battery is charging?
(Lights are the only 12v fixtures in trailer)

Thanks!

Francesca

[RJay]

That is a really good question Francesca! The 12 power you use in you RV is subtracted from the charge current going to your batteries, which should be taken into account when determining how long it should take to charge your batteries as well as the current setting of the charger/converter/inverter.

[Francesca]

Thanks, Rjay!

I'm thinking of tossing my old converter out and replacing it with a smart charger.
I was hesitating due to being unsure about using the lights while charging.
Now I think I understand the way it all works!

Francesca

[GreatWhite]

Thanks all. Maybe I don't need a charger at all. At Dave's suggestion, I checked the converter and found it should be perfectly sufficient. It's an Inteli Power PD9160A. I'd guess the only thing I might want to purchase would be an inexpensive Charge Genie. It has a smart 3 step process.

Some of the things I "think I should know" are being well clarified by these discussions. The batteries I got from Costco, as mentioned have a Mfg Date of 06/11. I opened them and the fluid was covering the plates but was not up to the fill mark. I filled with distilled water, installed and connected. They were at, I believe, 12.4 v. After having the Battery Minder charger on all night at < 2A.. they were up to about 12.9V. We'll see what happens now that I have them hooked up to the charger/converter.

Thanks again for the input(s)

Bill

[Dave78Chief]

GreatWhite,
Now that I know what you have, I can better advise you. The PD9160A (RV Power Converter/Chargers) is a very good converter but does require the additional PD9105 Charge Wizard option in order to function as a full featured 3 stage converter/charger (PD9105, PD9105G Charge Wizard). Shop around and you can find them for less than $30. Without the Charge Wizard option, the unit only puts out 13.8 volts which is really to low for charging but would be to high for battery maintaining. In fact, a constant 13.8VDC applied to a fully charged battery can evaporate the water fairly quick if no other loads are drawing off the ecess amperage. The battery maintain mode (float) only puts out around 13.2VDC because of that.

Dave

[GreatWhite]

Yes, Dave.. I said Charge Genie.. buy you were correct in calling it the Charge Wizard. I'm going to order one when I get back from my trip this weekend. In the meantime, I'm going to put my Battery Tender back on the 4 pack.. that should keep them topped off without any over charge.

Next step... pull the rear wheels.. get a hernia.. and install the airbags.

[wa8yxm]

Quote:

Originally Posted by Francesca Thanks, Rjay! I'm thinking of tossing my old converter out and replacing it with a smart charger. I was hesitating due to being unsure about using the lights while charging. Now I think I understand the way it all works! Francesca

If you have an older "Single Stage" converter.... Upgrading is a very very good idea, and what's more it does not (long term) cost any thing because where as say a Magnetek can fry your batteries in just a season or two a PDI 9200 line may well take 5-10 years to do the same damage.