TAB400 battery options

greenjacket

Put it down to newbie ignorance! On our first off grid trip the battery went flat in 10 hrs with only the fridge and occasional water pump and light use. I did let the trailer stand for 3 months before our first  winter and then I hooked it up to a battery tender, but it had been flat for some time. I fear that I have ruined the battery and would like to get some advice about options. Would a lithium battery be better for off grid camping?

N7SHG_Ham

That use shouldn't have killed the battery, so it must be toast from the winter? If you have the two 6v set up, BattleBorn sells a litiuim in a GC2 size, two of those and cables to parellel them would give you 200 ah of usable battery. Of course you will need to maybe upgrade charging, but temporarily probably can get by with stock converter, next up would be swapping the guts for a progressive dynamics drop in litiuim charger section.

greenjacket

We have an extremely heavy 12v AGM battery. NuCamp switched to 2x6v soon after we bought our trailer. We want a set up that will give us 3-4 days off grid with modest battery use. Maybe 2 x 6v plus a solar panel would work? I believe lithium are much more  expensive.

Verna

@greenjacket, I’ve spoken with another 400 owner whose single 12v AGM Battery went bad in his 400. He replaced it with two 6V Golf Cart AGM batteries from an Interstate Battery dealer. The model number he used from Interstate was #PV06V27, AGM batteries with 220aH.

His original battery did not come with s plastic box like my dual 6V has, so he was able to have the Interstate dealer attach the batteries to the floor. He has solar and has not told me if there has any problems since he had the new batteries installed. 

I have 200 watts of flexible solar panel on my 400’s roof that work wonderfully during overcast weather. 

DenisP

Our 2018 400 has the two 6v AGM batteries and 200 watts of solar and have the same experience as Verna. We have no problems with moderate power usage dry camping for days with the 2 6v AGMs. I love the flexibility that solar gives. 

pthomas745

@greenjacket we need more info on how you monitor your battery state of charge, and what you mean type of "battery tender" you used to charge it before leaving.   Was the battery switch off while the trailer was in storage?   What do you mean by "flat" and what are you using to determine that?

Not every tow vehicle charges while driving, so do you know if yours does?

I'm finally seeing reviews on lithiums that point out that they would only seem to be cost effective for people who live in or use their trailers quite a lot.  I don't know what the tipping point would be (60 days? 90?) to get your money's worth for lithium's many cycles compared to how long the trailer will last or will be kept by the owner. 

greenjacket

@pthomas those are some good questions, which highlight how little we know about trailer life and especially battery life !
The only battery monitoring we did was via the panel, making sure more than half the lights were on. We had only used the trailer a couple of times last year and each time we were connected to shore power. In the 3 months prior to winter the trailer was standing and I can't be sure that the battery disconnect switch was off. A neighbour who owns a trailer said she took the battery out and hooked it to a battery tender for the winter months.
I heard that plugging the trailer into shore power for the winter would keep the battery charged but we were unable to park close enough to our house to do that. So we removed the battery - very heavy! - and connected it to a charger,  a CTEK multi US 3300 in the garage. The green light stayed on all winter but I fear the damage has been done. How can I check if the battery is useable or not? I checked today and there is no power, even to the panel.
Good question about charging while towing. I really have no idea or how to find out the answer. We tow the TAB 400 with a Toyota FJ Cruiser.
From what I have read, I think Lithium is more than we need. Maybe, if our battery is fried, 2 new 6v batteries and a portable solar panel may give us what we need. Thoughts?

Sharon_is_SAM

@greenjacket, I know you are still on the learning curve regarding your TaB and battery.  Several things you need to know about the AGM battery/batteries that are used in the 400.  The benefits include:  very decent capacity of 225 amps, once fully charged they maintain their charge with the battery switch turned off for multiple months, they don’t need to be kept on a battery tender, (they do not need to be removed from the TaB), they do not freeze, they are almost maintenance free.

You also need to know that you need a good battery monitor as the installed KIB monitor can reflect “fully charged” when only actually 60% charged (another member’s recent experience), you need a smart charger compatible with your chosen battery.  You should try to limit discharge to 50% for maximum cycle life/duration of the battery, but AGM are much more resilient than typical wet cell batteries.

Lastly, only after you know how you camp and determine your actual amp needs then you will know your battery/power needs.

Those single, huge AGMs had problems related to blown fuses and inability to recharge from the converter when heavily discharged, so just as well that 6 volts are in your future.  I would follow Verna’s lead and start your solar with a 100 watt Renogy suitcase until you further define your needs.

greenjacket

@verna That sounds like a good combination. We bought our TAB 400 just before NuCamp switched from 1 x 12v to 2 x 6v batteries and it did not come with any solar panels on the roof. Which brand of portable 200w solar panels do you think is best?

greenjacket

@Cbusguy I'm pretty sure it's done, doesn't hold a charge for long 

greenjacket

@Sharon_is_SAM Thanks that is very helpful. You make the 12v AGM that came with the TAB 400 a solid choice, despite the fact that it's hard to get at and weighs a ton!
It looks as though I need to go to a battery shop to get the monitor and charger. If I get 2 x 6v batteries could I connect them to the CTEK tender in the winter ?

Sharon_is_SAM

@greenjacket (there must be a story behind that user name - are you a Master’s winner?)

You can’t beat the capacity of the two 6 volts.  We have the regular tub on a clamshell, so space and tongue weight were a concern.  Even the two 6 volts will maintain their charge without a tender.  You just charge them up and retrieve them in the spring.  You can check on them once in a while via the monitor if you want.  You need a 12 volt smart charger that can handle AGMs as they have specific charging parameters.  Many good brands of chargers  (Nocco, Deltran, CTEK) and for AGMs a lower amp (slower charge) is better than a higher amp.  2-4 amp is fine.  You need to read your battery literature as it will define your charging parameters as well as help you set up a battery monitor.  

Regarding the battery monitor, lots of us have Victron, but there are others as well.  A shunted monitor is best - gives you the most accurate state of charge.  I don’t think a battery shop sells these types of monitors.  They are available online or a dealer would be able to access and install.