Replacement battery question

[funfyzics]

I need to replace two batteries on my epro 14fk trailer. This is the numbers off of the 2 batteries
hd24-dp 405cca 505mca. They are Interstete batteries. Walmart has a comparable battery but at 1000 MCA. They are listed as marine batteries. And have a number of MS 24 My question would it be alright to use 2 batteries with 1000mca each or should I try to get a closer match?

Thank you

Brian

[markopolo]

The battery you listed is:
Size: Group 24 Deep Cycle
Amp Hours: 64
Length: 11"
Width: 6 7/8"
Height: 9 1/2"
Weight: 41.2 lbs

With RV's the Amp Hour rating and Deep Cycle type are important. More Amps Hours = more time the batteries will last until recharge. Deep Cycle means it is built for repeated deep discharges. You don't want a starter type battery for RV use. Deep Cycle on the label would be preferred. Marine/RV on the label would also be OK.

If you have space to fit larger batteries then Group 27 is the next size up.

If the batteries are on the front of trailer you might need to stay with the same size and close to the same weight.

[SteveJ]

Iff'n you're going the Walmart route, I would suggest the Maxx series deep cycle. The "code" should be 24DC or DC24. It allegedly is built better for deep cycles and does come with a two year full replacement warrant at any Walmart, no receipt required. Their computer can track it.

I run a group 29dc Walmart Everstart Maxx that has worked well for about a year and a half, about seven months of mostly extended boondocking with solar.

BTW, unless something has changed, Everstart uses a 1 amp rate to display their amp hour capacity which inflates the capacity number. This is misleading as almost everybody else uses a 20 amp rating.

[RossWilliams]

As far as I know, most batteries use a 20 hour discharge to determine AH. So if you have 240 AH rated battery it will be considered fully discharged after discharging at 12 amps for 20 hours, if you have a 120 AH rated battery it will fully discharge at 6 amps for 20 hours.

You can inflate the AH by discharging over a longer period of time since discharging more slowly provides total greater capacity. So a battery could be discharged at 1 amp for 240 hours and rated at 240 AH, but it would have a considerably lower actual capacity than the battery rated at 240 AH discharged over 20 hours.

The actual difference varies and some companies offer AH ratings at different lengths of discharge. If you are buying batteries to run an air conditioner that draws at a rate of 100 amps an hour you might want to compare AH at much shorter discharge times. If your batteries are only being used for a few LED lights, you might want to look at AH ratings over much longer periods. You might want to size your battery bank based on the rating most appropriate for your actual use.

[booster]

Originally Posted by RossWilliams

As far as I know, most batteries use a 20 hour discharge to determine AH. So if you have 240 AH battery it will be considered fully discharged after discharging at 12 amps for 20 hours, if you have a 120 AH battery it will fully discharge at 6 amps for 20 hours. You can inflate the AH by discharging by using a longer period of time since discharging more slowly provides total greater capacity.

As SteveJ mentioned, the ratings, especially for the combo and "DC" series of gp24 and gp27, seem to be shifting to make them look better on paper in respect to AH rating if it is given at all. I found this at Costco also once I was finally able to find the AH rating. It was the 100 hour rate, so really looked good compared to a 20 hour rate.


Even though the DC series type batteries are listed as deep cycle, they don't appear to be true deep cycle wet cells, but are the low water use combination start/deep cycle versions as they use nearly no water in with decent charging and use. I have been using them in our Roadtrek as starting batteries as the bit of extra capacity over pure starting batteries is nice to have.

[Bud]

Originally Posted by booster

As SteveJ mentioned, the ratings, especially for the combo and "DC" series of gp24 and gp27, seem to be shifting to make them look better on paper in respect to AH rating if it is given at all. I found this at Costco also once I was finally able to find the AH rating. It was the 100 hour rate, so really looked good compared to a 20 hour rate.


Even though the DC series type batteries are listed as deep cycle, they don't appear to be true deep cycle wet cells, but are the low water use combination start/deep cycle versions as they use nearly no water in with decent charging and use. I have been using them in our Roadtrek as starting batteries as the bit of extra capacity over pure starting batteries is nice to have.

Hi booster,

I have the 27DC's which state 'Marine, Trolling..." right on the batteries. I've used 2 now for 3.7 years. Before use I made certain to fully charge both batteries. These are the only batteries I have ever maintained appropriately since birth, mine and the batteries.

Maybe you can comment on this: In the beginning, 6-12 months, I added water, noticeably. Since then almost no water! Why? The use has been about the same each year. Last trip was a couple of months ago, 5-6 thousand miles.

The batteries do seem happy still.

Bud

[booster]

Originally Posted by Bud

Hi booster,

I have the 27DC's which state 'Marine, Trolling..." right on the batteries. I've used 2 now for 3.7 years. Before use I made certain to fully charge both batteries. These are the only batteries I have ever maintained appropriately since birth, mine and the batteries.

Maybe you can comment on this: In the beginning, 6-12 months, I added water, noticeably. Since then almost no water! Why? The use has been about the same each year. Last trip was a couple of months ago, 5-6 thousand miles.

The batteries do seem happy still.

Bud

That is pretty odd, Bud, I have never really seen or heard of that kind of water use. New batteries, often will go down a bit on the first couple of cycles and bouncing rides down the road, probably form air pockets getting out, but not that long. The three DC labeled ones we have had all behaved that way. All three also did not come up as high a specific gravity as the deep cycles we have had, peaking out at about 1260.

[Bud]

Originally Posted by booster

That is pretty odd, Bud, I have never really seen or heard of that kind of water use. New batteries, often will go down a bit on the first couple of cycles and bouncing rides down the road, probably form air pockets getting out, but not that long. The three DC labeled ones we have had all behaved that way. All three also did not come up as high a specific gravity as the deep cycles we have had, peaking out at about 1260.

It has bothered me booster, not knowing why and not finding an answer. The last 2+ years I've only checked the water in one battery every 6 months, the easy battery to access and you know which one with an 05 190 Roadtrek. I don't add water. Then after a year I check them both adding almost no water. Both batteries needed about the same for 6-12 months, then almost none with both.

I have no explanation, not even a clue like hot weather, overcharging, different usage, .......... Oh, hold up, maybe it is my super cabling and dumb charger. Like just running the cable from one battery to the next.