Can I replace 12V AGM battery with 12V deep cycle battery?

[iainmcc]

Due to (my) rookie mistakes, needed to replace Lifeline AGM battery this week. With no power to tongue jack this replacement was time sensitive.
Quick trip to Camping World and I picked up a 12V deep cycle battery, not AGM. Power is restored to the tongue jack but not to interior lights. Does this suggest that I need to replace AGM with AGM?
There is a solar unit on the roof, installed by original owner.

Our model is a 2017 22FB Bambi Sport, FYI. Thanks in advance!

[lsbrodsky]

The lights, loads in general, do not care what kind of 12v battery you have. Check fuses, whatever you did may have blown one or more.

Larry

[SeaLevel]

All of the batteries in your battery bank should match by type etc., and the solar charger may be setup for AGM instead of another battery type. But I would expect the lights to still work if things are connected properly and no fuses are blown.

[BayouBiker]

Sorry to hear of your difficulties. Ruined batteries are bad enough, piling on new issues just adds insult to injury.

The deep cycle Wet Lead Acid batteries have no influence on your new issue, they perform similarly. The differences are in the charging characteristics. AGM batteries are a much better choice when you have solar connected because the daily recharging profile tends to consume water but AGM design mostly eliminates this issue. If you can, I would return the new batteries and swap with AGM batteries so you won't have to frequently add water. There are other advantages I won't mention here. If you choose not to go back to AGM's its ok, just check water level often while the solar charger or shore power converter is active.

The dead batteries and the act of replacement likely contributed to the new issue though because it's too much of a coincidence.

So.....

1) Did you connect all the wires exactly the same as before? Are you sure?
2) Perhaps a primary fuse blew due to low voltage and high surge amps when you hooked up and found the batteries damaged. Your manual has a wiring diagram that shows the thermal breakers and fuses.
3) Is the Use/Store switch passing power?
4) Do the interior lights work with shore power - the converter connects to the load center not the battery leads.
5) Do they work with the tow vehicle connected - that circuit does not use the main fuses and thermal breakers.

Check those things and see what you come up with. Are you handy with a multimeter?

[OTRA15]

Originally Posted by iainmcc

. . .
. . . needed to replace Lifeline AGM battery this week . . .
. . .
Our model is a 2017 22FB Bambi Sport, FYI.
. . .

Does your model only have 1 battery?

Good advice so far, especially to replace both batteries with 2 identical, if so-equipped.

[iainmcc]

The use/store switch was the issue. Learning everyday with this little beauty

Thanks to all that responded so quickly, and Colonial AS for being super responsive too!

[OTRA15]

That info should be in your owner's manual IMO, which many new owners don't bother reading right away.

BTW welcome to the forum . . . and happy trails!

[jimdelane]

Odd are the AGM you replaced was a deep cycle marine AGM. That is a kind of hybrid start/deep cycle battery. I assume that the deep cycle was a flooded lead acid FLA). You need the deep cycle ability if you want to run cabin lights, etc. Your cycle life on a start battery is a lot less than on a deep cycle. They are designed to be discharge 5% or so and then charged back up. You can expect around 400 cycles with a FLA. You will need to check it regularly to make sure it has enough water. Ideally you should charge it 100% daily to prevent sulfation build up and crystallization. You should equalize it every 1-6 months to prevent stratification of electrolyte. Do not let it have a depth of discharge below 90% for any extended period. With proper maintenance, this battery should last a while.

[franklyfrank]

Originally Posted by BayouBiker

Sorry to hear of your difficulties. Ruined batteries are bad enough, piling on new issues just adds insult to injury.

The deep cycle Wet Lead Acid batteries have no influence on your new issue, they perform similarly. The differences are in the charging characteristics. AGM batteries are a much better choice when you have solar connected because the daily recharging profile tends to consume water but AGM design mostly eliminates this issue. If you can, I would return the new batteries and swap with AGM batteries so you won't have to frequently add water. There are other advantages I won't mention here. If you choose not to go back to AGM's its ok, just check water level often while the solar charger or shore power converter is active.

The dead batteries and the act of replacement likely contributed to the new issue though because it's too much of a coincidence.

So.....

1) Did you connect all the wires exactly the same as before? Are you sure?
2) Perhaps a primary fuse blew due to low voltage and high surge amps when you hooked up and found the batteries damaged. Your manual has a wiring diagram that shows the thermal breakers and fuses.
3) Is the Use/Store switch passing power?
4) Do the interior lights work with shore power - the converter connects to the load center not the battery leads.
5) Do they work with the tow vehicle connected - that circuit does not use the main fuses and thermal breakers.

Check those things and see what you come up with. Are you handy with a multimeter?

Are AGM batteries worth the extra cost beyond not having to worry about maintaining the water level.
My original Interstates will be due for replacement this year and I would like to get something that is less hassle and more reserve power.
We don't boondock but overnight frequently and it be nice to have the additional reserve. I don't have solar either other than a suitcase set up which I have yet to use.

[BayouBiker]

AGM batteries resist sulfation and stratification so they don't require equalization charges once or twice a month but that is not a major deal either. Most AGM batteries will tolerate 10-20% greater discharge with the same cycle life so the actual capacity of an AGM is 70% of listed verses 50% of listed for a wet cell. That probably just compensated for the lower capacity to begin with. They can be mounted on their side. I don't think the other differences are worth mentioning as they don't represent significant advantages.

[jimdelane]

AGMs do not have stratification because the electrolyte is suspended in the glass mat.

All AGMs are not the same. Lifeline makes some of the best AGM batteries available using better technology and better materials. (ref p12 - Lifeline Tech Manual). You also pay more. The less you pay, the more work you have with maintenance and replacements - your product choices range from cheap SLI flooded lead acid to cost effective but expensive LiFePO4 lithium batteries.

Lifeline recommends installing doubling the rated capacity to meet load requirements and not discharging over 50%.
Discharging to 70% will reduce cycle life by over 30% (ref p40 - Lifeline Tech Manual). Also cycle life decreases 50% for every increase of 10 degrees Celsius. (ref p23 - Lifeline Tech Manual) - this is true for all lead acid batteries. (ref p40 - Lifeline Tech Manual)
'if 100Ah is required, select at least 200Ah...limit the average depth of discharge to 50% and will dramatically extend life of the battery" (ref p18 - Lifeline Tech Manual).

Most AGM do not recommend equalization. Lifeline has a equalization (conditioning) routine but only recommends it when you see a loss in capacity. Basically, when the battery has sulfated to the point it is dying, it is something to try to eke out a little more life. Can't hurt much - might help.(ref p21 - Lifeline Tech Manual).

Lifeline Tech Manual http://lifelinebatteries.com/wp-cont...cal-Manual.pdf

If you can afford lithium batteries - you will be happier in the long run.