Need Battery Help

[paof6]

Our 2019 25B has the same set up--under step batteries (the batteries are SO tight in there I have to remove the gasket around the top of the battery compartment to get them out) with 2 OE group 24 DCM Dual Purpose Napa batteries (rated at 75ah each but in real world turned out to be 60ah usable). We struggled for about a year trying to make the batteries work. The original Napa's would not last a winter night with the furnace running and inverter on for my CPAP (no heater). The NAPA batteries always tested good but didn't have the capacity. About a year ago as a shot in the dark I put in 2 Walmart 24DC Group 24 batteries and have had good luck so far. My under step location leaves absolutely no extra room without some big mods to install larger batteries. We have 400 watts of solar on the roof & a 100 watt suitcase panel and with this setup our only limitation is black & gray tank sizes. We have a propane fridge btw.

[Bobn1957]

I use Interstate Batteries, good quality and I highly recommend them!

[mikeh2obury]

Before you replace the battery check your power center. There are breakers for the AC part and fuses for the DC and there are 2 40amp fuses for the Charger and inverter. Check those 2 fuses. If burnt replace and then either drive to charge them up or plug in to power.

[JeffRobinson]

Originally Posted by Webad

We have a 2019 View whose house batteries are not holding a charge. We bought it used 6 months ago from a dealer who took it in on a trade from the original owner. Being new to RV ownership I have no clue how to replace them. The number on the top is NAPA 24DCM My husband is not the handiest of guys so I need some advice/direction on what to buy to replace them and how/where I would get them installed. Thanks!

Keep in mind that you can only run your battery down to 1/2 way or you will damage it. If you have a Lithium ion you can run them dead and not hurt them.

[Rick 99037]

Lots of useful comments here. Clearly they could have failed, but it is also possible they've got something drawing them down. At least on my unit, having the batteries turned off doesn't disconnect the gas detector, for instance.
So disconnecting the black ground side, hooking up a charger, and getting them well charged, checking their voltage, waiting a while, and checking their individual voltages to see if they are going down would be a helpful clue.
As a dual use battery, having them draw tested for free, at their local O'Reilly, AutoZone type place is useful too. But note, they are not designed for the kind of current draw a typical care battery is made for. I think they know that though.

[BobC]

Originally Posted by JeffRobinson

Keep in mind that you can only run your battery down to 1/2 way or you will damage it.

Not totally true. Discharging below 20% will cause actual damage that affects the battery's usability. Discharging between 50% and 20% will reduce the battery's overall lifetime in terms of discharge cycles but won't affect its current usability. In fact, if you only discharge to 70% on average, you battery's lifetime in terms of discharge cycles will be greater than at 50%.

This is significant if you routinely do so, but insignificant if you only do so occasionally. Some sources argue that the extra use achieved by routinely going below 50% compensates for the reduced number of discharge cycles. According to those sources, the total, lifetime amp hours produced by the battery is relatively constant.

50% is a good design factor but we shouldn't live in fear of discharging below that as long as we don't go below 20%.

This information is available on many battery manufacturers' websites and some include tables and/or graphs.

Unless we boondock all or most of the time, most of us probably don't discharge to 50% on average. Let's say that 70% of the time you only discharge to 80%, 20% of the time to 50% and 10% of the time to 25%. On average you'd only be discharging to .56 + .10 + .025 =68.5% for a somewhat greater cycle lifetime than at an average of 50%.

[gurroz]

Originally Posted by Alphadog

Seems a bit premature for 2 year old batteries.

I don't think age has much to do with it. Dealers run batteries down to zero all the time, which will kill a battery. A lot of RV owners have no idea that drawing a battery below 50% state of charge will damage the battery. Unfortunately, when we buy used we have no idea of how that battery was used or abused.

[BobC]

Originally Posted by gurroz

A lot of RV owners have no idea that drawing a battery below 50% state of charge will damage the battery. Unfortunately, when we buy used we have no idea of how that battery was used or abused.

Again, damage means the battery won't work properly. As I previously stated, discharging your battery between 50% and 20% won't damage it in terms of its ability to function properly but will reduce its total cycle lifespan and even that is dependent on the average SOC as long as you don't go below 20%.

We may be dealing in semantics but, to me, there's a big difference between discharging below 20% once and having a battery that won't work properly any more and routinely discharging below 50% and experiencing a somewhat lower lifespan in terms of discharge cycles.

https://www.solar-electric.com/learn...tery-faq.html/

I do agree that we can't count on batteries that come an RV to be un-damaged.