want to add a second battery.

[marcus220]

hello folks,finally got my no 12 volt problem fixed,it was a fuse.thnx for all your help.now,i currently have 1 battery in my 16' rockwood pop-up.i want to add a second one.is it ok to just run a jumperwire from each battery terminal?can i charge both by connecting my generator to one battery?i have 2 seleltor switches on my boat,do i need the same hookup?thnx marcus

[Jjs2000z]

I would suggesting adding two 6 volt batteries

[Witch Doctor]

Originally Posted by marcus220

hello folks,finally got my no 12 volt problem fixed,it was a fuse.thnx for all your help.now,i currently have 1 battery in my 16' rockwood pop-up.i want to add a second one.is it ok to just run a jumperwire from each battery terminal?can i charge both by connecting my generator to one battery?i have 2 seleltor switches on my boat,do i need the same hookup?thnx marcus

The real answer is yes if they are the same. The best way is to have 2 of the exact battery's and age. Just go plus to plus and minus to minus. The other way you mention would be a selector switch A&B or both. That way you could use it to charge either one. But if they are the same age and AH there is really no use doing that. I have 2 12 volt on one disconnect. They are both either off, on or charging. Make sure your wire is big enough so you don't have a voltage loss. Bigger is better less resistance. But I been wrong before so be warned. We got some good batteries guru's on line Barry is one of them, also wiretim......

[BigTJohn]

2 =- 6 vdc batts will cost you more than adding the 1 - 12 vdc. How old is the batt you currently have? If it is more than 6-9 months older than your new (or to be purchased batt) then the 2 - 6 vdc golf cart type batts would make sense. You can charge 2 - 12 vdc from a single input, the selector type sw as on your boat does have its advantages. Try not to mix old and new batt, as the old one will keep trying to "charge itself" via the new, stronger one. Search this forum for more detailed info and hookup tips.

[Triguy]

Originally Posted by marcus220

hello folks,finally got my no 12 volt problem fixed,it was a fuse.thnx for all your help.now,i currently have 1 battery in my 16' rockwood pop-up.i want to add a second one.is it ok to just run a jumperwire from each battery terminal?can i charge both by connecting my generator to one battery?i have 2 seleltor switches on my boat,do i need the same hookup?thnx marcus

You have lots of option.

You can add a new 12 volt in parallel with your original IF the two batteries are the same type (flooded, AGM, etc), same size, and same age. You cannot mix batteries of different types and its not recommended you mix batteries of different sizes or age.

If you have two different 12 volt batteries, you can use them separately (not connected in parallel) and various battery disconnects will allow you to switch manually between them.

If you want to perfectly match them, you will need to buy two new batteries and can then connect appropriately (two 12-volts in parallel or two 6 volt batteries in series).

[bikendan]

this website should be required reading for any new RV owner:

The 12volt Side of Life (Part 1)

there are Part I and II.

[marcus220]

Originally Posted by bikendan

this website should be required reading for any new RV owner:

The 12volt Side of Life (Part 1)

there are Part I and II.

yhnx bike for that link,that was very informative.

[marcus220]

i decided to go with 1 deep cycle group 27.did'nt really have room for 2 batteries.i do carry a new spare however.i have a 200 eu honda generator with a battery charger.am i better off charging the battery using the generator and charger?or use the alligator clips from my generator to the battery?also,should i disconnect the trailer leads off the battery before i charge the battery? thnx again. marcus

[bikendan]

use the trailer's converter. just plug the shore cord, with a 30-20 amp adapter, into the outlet on the Honda.
way easier than using a separate battery charger and WAY more efficient than using the 12v battery charging cables supplied with the Honda.

[marcus220]

Originally Posted by bikendan

use the trailer's converter. just plug the shore cord, with a 30-20 amp adapter, into the outlet on the Honda.
way easier than using a separate battery charger and WAY more efficient than using the 12v battery charging cables supplied with the Honda.

what rate of charge is that?i just read the converters rate of charge does'nt compete with the charging input of a charger.PLEASE READ THIS.As stated above, the converter in your RV really isn't designed to be a decent battery charger. It's main purpose in life is to provide 12 volt power for your rig while you are plugged in to an A/C outlet. Since the converter is designed to not exceed a voltage of about 13.5 volts, it will never fully charge your batteries. Also, after it has succeeded in partially charging your batteries, it will then commence to boil off electrolyte, as the "float" voltage is too high (should be about 13.2 volts max.). If you plug your rig into A/C power for months at a time, you MUST keep a close eye on your battery's electrolyte level. It is very common for a converter to boil a battery dry in a month or two. Don't let it happen to you! If you must live with your converter, it is a big help if you unplug it or switch it off when the rig is in storage and attached to A/C power. Just run the converter overnight once a month or so and it will be much easier on your batteries. Another significant disadvantage to the converter is that most units aren't capable of delivering their rated amperage to the batteries to charge them. Older converters will only manage about 10 or 15 amps and will put out significantly less when powered by a generator.

[raspivey]

This mainly relates to older converters. Most newer converters are 2 and 3 stage chargers as well. Having said that, I leave mine disconnected and on a "smart" charger when not in use.

[marcus220]

do you then reccomend charging thru the converter?the trailer is a 2007,probably has the 3 stage converter.

[raspivey]

You'll get different opinions on it. Without knowing the model of converter you have, it's hard to say what it's capability is. I would say it wouldn't hurt it at all in the short term...long term could be another story, but all that would be required is to keep an eye on the water levels in the battery (a good habit to be in anyway). When it's just sitting at the house, I use a separate charger that's designed to be left connected for extended periods just leave it plugged in all the time. When I'm plugged into hookups at a campsite, I let the converter do it's thing.

Reading back on your posts, though...I was assuming you were talking about charging in general. If you were asking about strictly charging from a generator, I'd say just run through the converter.

[bikendan]

the converter on my '07 Roo is a WFCO 3-stage converter and i've been using it to recharge my two 12v deep cycle batteries for 7 years now.

i've never had to use anything else.

[marcus220]

Originally Posted by bikendan

the converter on my '07 Roo is a WFCO 3-stage converter and i've been using it to recharge my two 12v deep cycle batteries for 7 years now.

i've never had to use anything else.

i will do that.thnx all.

[marcus220]

Originally Posted by raspivey

You'll get different opinions on it. Without knowing the model of converter you have, it's hard to say what it's capability is. I would say it wouldn't hurt it at all in the short term...long term could be another story, but all that would be required is to keep an eye on the water levels in the battery (a good habit to be in anyway). When it's just sitting at the house, I use a separate charger that's designed to be left connected for extended periods just leave it plugged in all the time. When I'm plugged into hookups at a campsite, I let the converter do it's thing.

Reading back on your posts, though...I was assuming you were talking about charging in general. If you were asking about strictly charging from a generator, I'd say just run through the converter.

just one more thing.the single new{fully charged} deep cycle battery will be running the blower on the furnance on the camper all night.its probably going to be around freezing,or under,at nite.will a recharge{thru the converter} say 2 hr.s recharge it for the next nite?can i wait till the next nite to recharge?thnx

[raspivey]

You only have about 95 Ah of capacity, maybe less as cold as it will be. You don't want to run them less than half full or you'll drastically shorten their life. That would mean approx. 40 Ah usable for one battery. That furnace is going to kill you. Without looking, I think it'll probably draw around 7A (7 Ah for each hour running). As an example, I always left ours on the bare minimum temp just to knock the chill off and bundled up really well. It ran about 20 min. every hour. If your situation was the same, you'd end up using about 21 Ah of battery in 9 hours with absolutely nothing else running our of your possible 40 Ah. Not enough to make it a second night.

Someone else will have to chime in on converter charging efficiency, because I'm not really up to speed...I believe that they put out around 3A charging and, if that's the case, it would take 7 hours to replace the 21 Ah you used.

If it weren't for the furnace, I'd say a two hour charge every day off of the generator through the converter would be fine to extend you a few days if you were careful. I had said that I would just use the converter before, but that was just to save you from packing another charger. Knowing more about what you're about to do makes me want to say you'd be better off with a higher amp battery charger plugged into the generator 110 in order to get a faster charge.

[marcus220]

Originally Posted by raspivey

You only have about 95 Ah of capacity, maybe less as cold as it will be. You don't want to run them less than half full or you'll drastically shorten their life. That would mean approx. 40 Ah usable for one battery. That furnace is going to kill you. Without looking, I think it'll probably draw around 7A (7 Ah for each hour running). As an example, I always left ours on the bare minimum temp just to knock the chill off and bundled up really well. It ran about 20 min. every hour. If your situation was the same, you'd end up using about 21 Ah of battery in 9 hours with absolutely nothing else running our of your possible 40 Ah. Not enough to make it a second night.

Someone else will have to chime in on converter charging efficiency, because I'm not really up to speed...I believe that they put out around 3A charging and, if that's the case, it would take 7 hours to replace the 21 Ah you used.

If it weren't for the furnace, I'd say a two hour charge every day off of the generator through the converter would be fine to extend you a few days if you were careful. I had said that I would just use the converter before, but that was just to save you from packing another charger. Knowing more about what you're about to do makes me want to say you'd be better off with a higher amp battery charger plugged into the generator 110 in order to get a faster charge.

thats what i thought.i don't have room on the trailer to install a second battery,but,i can however,when set-up,set in on the ground then hook up the jumper wires.what you say?

[raspivey]

That would work fine provided:

1. Both batteries are the same size, type, and age.
2. Connected in parallel (+ to +, - to - ).

If they're not the same size and what not, you can always just swap them out as needed and use them one at a time.

If you do end up connecting them together, I'd make sure they were protected from the elements (covered / water tight). Also, get a multi meter and periodically check the voltage on them after they've been sitting a little while with no load on them. Full should be around 12.7 - 12.9 and you don't want them to get below about 12.1 - 12.2 V. As soon as you get home, get them fully charged up. Going too low too often and leaving them partially discharged will have you replacing them after a year instead of five or more.

[BarryD0706]

You need to find out what model of converter you have. They are not low-amp chargers. My Progressive Dynamics can be from 30 to 80 amps (but the battery probably isn't going to pull that much). They state that a discharged battery will be recharged to 90% within 2-3 hours. (It can take up to 12 hours to get the last 10%.)