Changing Battery Size? 4x L16 to 8x GC2?

[mliemon2]

My house bank needs to be replaced, and I'm thinking of swapping from 4x 6v L16 AGM batteries (@120 lbs each) to 8x 6v AGM golf cart batteries (@55 lbs each) for easier replacement and handling. In fact comparing the amp hours, the GC2 batteries would get me 880 AH vs the 800 AH (at 12V) that I currently have. I'm trying to figure out if there's any downside?.... it doesn't seem like it? Other then I'll need to build a shelf to store them all. Anyone have any insight?

Thank you!

 

[Flatswing]

If you have reasonable access & can hire some muscle to exchange them, another less expensive option is replace the existing AGM’s with 6v FLA L16’s. You will gain Ahrs, and very durable - expect 7 yrs+ if you avoid DOD<50%. Deka through NAPA are hard to beat.
Either way if you switch to GC2’s or L16 FLA, invest $100 or so in a battery minder system. Watering becomes a 5 minute task, don’t have to even open battery boxes. The easier it is to maintain FLA, the longer they last.

 

[SteveK]

IMO, if you are staying with lead acid batteries, then stay with L16, taller and less footprint. 8 GC2 will cover twice the footprint

 

[mliemon2]

IMO, if you are staying with lead acid batteries, then stay with L16, taller and less footprint. 8 GC2 will cover twice the footprint

Sticking with AGM, which is what I currently have. The footprint would be the same, but the hight wouldn't. I'd be having a battery shelf built, so it would be 4 GC batteries on the bottom shelf, and 4 GC on the top.

Shelf would have a footprint of 24" L x 16" W x 30" H

 

[Delta Riverat]

Have you considered LiFePO4?

Two of these would give you 920 AH, weigh 87 pounds each.

 

[tiltrider1]

Have you considered LiFePO4?

Two of these would give you 920 AH, weigh 87 pounds each.

This is a good question. With the cost difference between AGM and LiFePo4 you could cover the conversation cost while loosing hundreds of pounds and gain more battery capacity.

 

[dhays]

Sticking with AGM, which is what I currently have. The footprint would be the same, but the hight wouldn't. I'd be having a battery shelf built, so it would be 4 GC batteries on the bottom shelf, and 4 GC on the top.

Shelf would have a footprint of 24" L x 16" W x 30" H

I have long been a fan of GC2 batteries, even flooded LA batteries. When I needed to replace a couple of 8d batteries (really odd chinese sealed LA battery that was between a 4d and 8d size) I went with 4 x L16 6v AGM because of the space I had available and found a very good deal on them. Yeah, they are heavy, but it was easier to get them in than it was to get out the old batteries. I did it myself using some tackle arrangements. In your case, I would tend to either stay with the L16 format, or look at going to LiPo.

If I had to replace my L16s now (may be sooner than later as a power outage just caused them to be deeply discharged) I would go with LiPo. As Delta pointed out, you could get 920 AH with two of those LiPo 8ds. Frankly, you could get one of those and still come out ahead of 8 x GC2s. The 880 AH of the GC batteries is going to give you 440 usable AHs at 50% state of charge. I try not to take my AGMs down that far as 50% discharge will still greatly reduce battery life over say a 70% SOC. Just one of those 460AH batteries would give you almost 370 AH at 20% SOC and have a much longer life. Two of them would give you over 730 AH at 20% SOC. 8 x GC2 AGMs are going to run you what $2,000? You could get two of those LiPo batteries for maybe $2,500. Certainly worth considering.

OTOH, if you have the space, you might consider FLA GC2s. If you can get a watering system, you would spend $800 or so on 8 of them at Costco. I've used them on a prior boat and they actually work well. However, you need to water them.

 

[ksanders]

I have the same L16 house bank.

If I were to replace my house bank today I would probably use one of these.

Go from 440 pounds total to 164 pounds total in about the same square foot of floor space.

Go from 420 AH useable (at 50% discharge) to 920 amp hours usable.

At a cost of fairly close to FLA

 

[ranger58sb]

My house bank needs to be replaced, and I'm thinking of swapping from 4x 6v L16 AGM batteries (@120 lbs each) to 8x 6v AGM golf cart batteries (@55 lbs each) for easier replacement and handling. In fact comparing the amp hours, the GC2 batteries would get me 880 AH vs the 800 AH (at 12V) that I currently have. I'm trying to figure out if there's any downside?.... it doesn't seem like it? Other then I'll need to build a shelf to store them all. Anyone have any insight?

If the house bank is isolated from start and thruster functions... (sounds like it is?)... I think I'd first look at LiPo alternatives.

Otherwise, I'd probably hire some muscle to swap new L16s for old. Saves engineering/building a new mounting system for 2x GC2s...

-Chris

 

[tiltrider1]

If you asked this question 3 years ago I would have said stick with the LA L-16 as the best bang for the buck. Now three years latter and the market place has flipped. The best bang for the buck is now LiFePo4 batteries. If you feel you need AGM’s then definitely look at cost savings of converting to LiFePo4.