Time to replace battery?

[Andy+Mo]

I am storing our camper and pulling out the battery to charge and store at home. It is an Interstate SRM-27 Deep Cycle marine battery. We are the second owner of our 303RLS and have had no problems with the battery. Had it tested and it has 600 cranking amps and registers 12.32 voltage after pulling it out of the camper. I am guessing it is probably the original battery so it may be 7 years old. I was not planning on replacing it, just charging it and tossing it back in when I head south in January. I don't know anything about batteries. Do you think I am good...recommendation to replace...?

[TribForce]

If it passes a load test, keep it. The battery in my 2013 dump trailer is original and still passes a load test and still works just fine. I has always been on a trickle charger when not in use.

[Jlawles2]

Look for a sticker on the side of the battery. Typically a single letter and one number or two. The letter signifies month with A being January and the number is the year of MFG. Thus Trib's battery would end in a 3. It could be 3 or 13 depending on MFG.

[Country Campers]

A fully charged wet cell battery typically has a charge of 12.73 volts, which states full charge. At 12.32 volts your is at a little less than 70% state of charge. It is recommended that wet cell batteries do not discharge below 50% or 12.1 volts. At 12.32 volts you are limited to about 20% battery capacity.

Brian

[Andy+Mo]

I checked for a sticker that shows the manufacture date but could find none unfortunately. I am sure it is probably a 2016 battery. The numbers I reported in my original post are prior to throwing the battery on a charger. I am charging it right now and was thinking of running it by Advanced Auto to have it checked again? Brian, when you say I am limited to 20% battery capacity, does that mean I will never increase the charge my battery can hold, even if I toss it on the charger. In other words, even though I just charged it, it will still only collect 20% of what it could when I first purchased it. It is kind of sounding like I should just grab a replacement. Thoughts?

[TucsonJim]

Andy+Mo

Over time, lead acid batteries lose storage capacity. They may test fine and deliver power upon demand. But after 2-3 years, they typically start to lose amp hour capacity. A typical Group 24 lead acid battery will provide about 90 amp hours of capacity when new. You can safely use about 50% of that power, or 45 amp hours without quickly degrading its capacity. After a couple of years, the overall capacity to store power may drop from 90 amp hours to 65 or 70 amp hours, and you can't tell during use. But you'll see it dropping to 12.1 volts quicker during use.

Many owners switch to lithium iron phosphate batteries now. Prices are dropping like crazy. LiFePO4 batteries can store more power, and don't degrade nearly as fast. Before LiFePO4 batteries were readily available, I'd cycle out my lead acid batteries every two years with fresh ones.

Jim

[Country Campers]

Andy+Mo

I was just going off of the information in your first post concerning battery charge state.
Here is a chart that shows wet cell battery charge state.


When you get your battery fully charged let it "rest" for half hour or so and check voltage. If that is a 2016 battery I would just replace it. Like Jim stated above I have replaced mine at 3 or 4 years previously.

Brian

[Jlawles2]

Typically the build date sticker is round and on the side. If you have not changed it and do not have history of it being changed, it's probably the original as most people never consider the battery as a maintenance item.

I'd probably err on the side of cautious and replace. Yes it's and expense, but depending on what brand you choose it could be decently economical vs the headaches and issues that pop up later.

[Andy+Mo]

Looks like it is better to be safe than sorry. Especially with a winter trip coming up. I think I will replace. I am curious Jim about what type of LiFePO4 battery I would replace it with if I were going to upgrade? And, will the system charge/operate just as it did with the standard battery? I may just go with the standard marine battery since I had good luck with the original. Just curious...

[TucsonJim]

Looks like it is better to be safe than sorry. Especially with a winter trip coming up. I think I will replace. I am curious Jim about what type of LiFePO4 battery I would replace it with if I were going to upgrade? And, will the system charge/operate just as it did with the standard battery? I may just go with the standard marine battery since I had good luck with the original. Just curious...

I went with Li Time batteries. I based this decision primarily on a tear down analysis that Will Prowse did on YouTube. Will is an amazing resource when it comes to LiFePO4 battery technology.

The LiTime batteries were 1/3 the cost of batteries from the traditional company that many of us have dealt with for years. Their warranty is five years vs. ten, but at one third the cost, even if they fail at five years, i'd still be better off cost wise.

Jim

[Country Campers]

Andy+Mo

You will need to update your converter/charger to a Lithium compatible one if you go with a Lithium battery. You may need to upgrade some wiring also depending on how you choose to set up the system.

Brian

[Andy+Mo]

Thanks for the information!