Adding a second battery....

MotocrossCamper · 03-23-2014, 01:06 PM

The Toyhauler we bought to try this year is an 04. Does anybody now how the older onboard chargers do with adding a second battery? Didn't know if I should be concerned with how it will affect anything. Having one battery just doesn't cut it for what we do.

Thanks

**KyDan** · 03-23-2014, 01:11 PM

You should have no problems with a 2nd battery in parallel with the other
one. Try to get same size and of course same voltage!

Good luck and happy camping!

OldCoot · 03-23-2014, 01:12 PM

Quote:

Originally Posted by KyDan

You should have no problems with a 2nd battery in parallel with the other
one. Try to get same size and of course same voltage!

Good luck and happy camping!

X2!

MotocrossCamper · 03-23-2014, 01:15 PM

Thanks! I just planned on buying 2 new matching ones.

golfmedik · 03-23-2014, 03:41 PM

Just get you a couple of battery cables at your favorite auto store with the eyelets on each end(if you buy deep cycle batteries) and hook 'em up.

showtime0022 · 03-23-2014, 08:59 PM

Make sure you buy deep cycle batteries. Regular batteries wont last as long.

camaraderie · 03-23-2014, 09:18 PM

1. Since you are going to replace 2 batteries...why not make the move to a pair of 6V golf cart batts and get real deep cycle performance cheaply. (Sams/Costco) use a single jumper cable between the + and - of the two batts...and attach your existing cables to the remaining + & - respectively to get a 220AH 12V deep cycle battery.

2. If you have an OLD charger that runs on a FIXED output voltage...you would benefit by changing it out for a 3 stage or 4 stage smart charger which would be more efficient and give you more life from your new batteries.

3. While your existing charger can charge double the capacity as you plan...it will take twice as long as it does now assuming it was not oversized to begin with. Ideally a charger should provide around 20% of capacity...for a 200ish amp hour dual battery bank this would mean a 40 amp charger would be about ideal. Don't know what you have now...but the IOTA DLS 45/iq4 with the 4 stage smart charger would be a good match FOR EXAMPLE. Amazon.com: IOTA DLS-45/IQ4 12 VOLT 45 AMP 4 STAGE AUTOMATIC SMART BATTERY CHARGER / POWER SUPPLY: Automotive

Hope this helps you make a good decision.

SKnight · 03-23-2014, 10:32 PM

I had three 12v batteries in my 2002 TT with a 35 amp converter and it never had an issue.

But I'll second the dual 6v option. In a few years when my current batteries go south I'll end up with four 6v batteries in a paired series/parallel setup.

camaraderie · 03-23-2014, 10:52 PM

Quote:

Originally Posted by SKnight

I had three 12v batteries in my 2002 TT with a 35 amp converter and it never had an issue.

I agree that your experience is both possible and likely.

My point was NOT that it wouldn't work....but that it would take longer. For example...lets take ONE 100 amp battery depleted to 50%. It would take your 35 amp charger 1.5 hours to replace those amps (in a perfect world... of course in the real world it will take about 3 hours.) Now let;s increase that bank to a 3 battery 300amp hour bank...depleted to 50% so we have to put back 150 amp hours...which means 4.3 hours of charging in a perfect world.
If yer boondocking that is a real pain in terms of the real world hours extra needed to get to 100%.
So...his existing converter amps will work...but 45 would be better in time listening to noisey generators, cost of gas, wear on the generator...and battery life since he would be getting a smart charger along with more amps. For around $150 bucks...well worth considering.

SKnight · 03-23-2014, 11:51 PM

I didn't say it was fast, but it worked. Actually I never timed it on the converter, what I did was carry a separate battery charger, had a multi position switch so I could run off one, two in parallel, or tie all three together. During the day I'd turn the switch to the single battery, then put the charger on the other two paralleled batteries at a 12 amp rate. Never took more than a few hours for the charger to auto off. Not sure how deep I discharged them percentage wise, but it worked for me.

Few hours of tv, overnight running an inverter powering my cpap. The panel would show 2/3 in the morning, however accurate that was.

bitNine · 03-25-2014, 02:57 PM

I will eventually be converting my trailer to a double golf cart battery setup. That was recommended by the dealer. I also purchased a 100W solar panel that should help recover the lost power without use of the generator when boondocking. Also switched all lights in the trailer to LED, as they are the #1 drain.

MotocrossCamper · 03-26-2014, 06:57 PM

Thanks everybody! I was considering the dual 6 volt route.

showtime0022 · 03-31-2014, 04:34 AM

6v batteries are a better option.

Witch Doctor · 03-31-2014, 05:02 AM

Quote:

Originally Posted by MotocrossCamper

Thanks everybody! I was considering the dual 6 volt route.

If I was to buy new batteries, I to would go with the 6 volt route, But if I was also to do that I would also think of installing a higher amp converter charger like the Progressive 4 stage. With the wizard you can force the charger to bulk charge and keep it there at 14.4V til 90% recharged then it will drop down to 13.6 absorption mode automatically. Your charging time would be cut way down. I would think that would be a must for anyone doing boondocking. At Least then you have control not the unit. I would at least get the 55 amp if not the 70 amp units. I'm a great fan of the progressive unit Fr has now changed convertors is my understanding. They tried them with FR3 unit first and now as of today will start to put them in all there units. They seemed to have said goodbye to WFCO brand. Plus there is a very good reason they did this. It is just a superior convertor. 2 fans, a larger heat dissipator and of course the wizard and will allow you to drop down to 13.2V. WFCO will not drop down to 13.2v out put and just will boil your water out, major reason of battery failures. Trust me the factory and reps read this forum.

Grateful · 03-31-2014, 05:34 AM

We have a residential fridge so was considering using 4 6v golf cart batteries in series and parallel to get amped up 12v. Would any changes be necessary to the electrical system with such increased amps? Thanks

camaraderie · 03-31-2014, 08:23 AM

Grateful... A couple of suggestions:
1. With a larger bank...access to each battery may be an issue. Consider getting one of the watering systems that let you keep everything topped up easily.
2. No changes to the electrical system are necessary...but if you boondock a lot...you might want to consider a way to more quickly charge your 450 amp hours of battery bank. You can easily and safely charge at 90 - 100 amps and if you don't already have a smart charger...now would be the time to get a large one. (Assuming you charge from a generator). If you don't boondock and stay plugged in most of the time, then you don't need a big charger...just a smart one but there is no rush on that...just un plug and disconnect the negative wire when the coach is fully charged and not in use so you aren't over cooking the batteries on an old system.

SKnight · 03-31-2014, 09:33 AM

I'll add to that, get a dual battery switch. Mine, which is out of an old ambulance but is still available, has off, battery 1, battery 2, both. So, two 6V in series with positive going to leg one, two more 6V in series with positive going to leg 2.

You can just turn them off, or be on battery set one while you run an independent charger on set two, or vice versa. Or tie them together to charge but it will take a typical house converter a good while to top them up.

Plus, when it's time to go home you can turn on one set and not overtax your vehicle charging system.

My switch is a Cole-Hersee Marine switch. Here's the modern version of what I have, you can go much lighter though since this isn't likely to see starting loads.

Battery-Related Products | Battery Selector/Master Disconnect SwitchesM-750 | Cole Hersee - Littelfuse

MotocrossCamper · 03-31-2014, 10:53 AM

I wouldn't call what we do boondocking technically.

Being at the race track we more often then not have the genny running 12 hours out of the day, if it's hot we never shut it off. So charging time isn't a main concern, they get plenty of that. Its just on nights we don't need the genny I like to be able to shut it off and make it through the night. We run an inverter and I have 12 volt plugs at both tvs and at the dinette. 2 12 volts have always got us through 4 hours of tv watching, phone charging, xbox running and keeping the fridge and furnace running all night.

I would think if the 2 cheap 12 volt energizer deep cells did it, 2 good 6 volts should be more then adequate.

Grateful · 03-31-2014, 05:11 PM

I appreciate your insight very much. We have only been trailering a few years and this is our first fifth wheel. Nice to draw on your experience and knowledge.

Grateful

glen1971 · 04-03-2014, 11:44 PM

If one 6 volt dies, you are packing up and heading home.. If one 12 volt dies, unhook it and you can still stay out, just being a little more cautious with power..
My trailer came with 1 12 volt when I picked it up.. I happen to have 2 - 12 volt 100 Ah Gel cells sitting around, so that is what 's in there now..

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