Low Profile Batteries

[OldManMirage]

Here is what I am considering. I can easily fit 4 of these laid on their side in the space I have.

These are Renogy 100AH batts for $210, free shipping.

https://www.amazon.com/Renogy-Batter...%2C2016&sr=8-3

Here is a slightly cheaper alternative. Is there a big difference ?

Weize 100AH Battery for $185, free shipping.

https://www.amazon.com/Weize-Battery...xpY2s9dHJ1ZQ==

I appreciate all opinions. Also, per Sailorboy1, I figured I would probably end up running the engine every other day or so to get the initial bulk charge and then let the solar top them up. It's the main reason I would upgrade my alternator to a "smart" one.

[sailorboy1]

Originally Posted by OldManMirage

Here is what I am considering. I can easily fit 4 of these laid on their side in the space I have.

These are Renogy 100AH batts for $210, free shipping.

https://www.amazon.com/Renogy-Batter...%2C2016&sr=8-3

Here is a slightly cheaper alternative. Is there a big difference ?

Weize 100AH Battery for $185, free shipping.

https://www.amazon.com/Weize-Battery...xpY2s9dHJ1ZQ==

I appreciate all opinions. Also, per Sailorboy1, I figured I would probably end up running the engine every other day or so to get the initial bulk charge and then let the solar top them up. It's the main reason I would upgrade my alternator to a "smart" one.

I would go with the Renogy probably as I have never ever heard of the other one.

I hope you mean upgrade your regulator to a smart one. Not that it will matter as you aren't going to run your engine for full charging. You should be thinking getting a Honda (or other brand) and more solar if possible to fit.

Good luck!

[PaulCrawhorn]

There are three AGM manufacturers worth considering for true deep cycle use in North America.

Lifeline, Odyssey and Northstar.

One imported Chinese brand I forget but not as good.

Saving money in upfront price will cost more per year as their cycle lifespan is so much lower.

And in general, Renogy is crap.

[79Endeavour32]

I have a 1979 Endeavour 32 shoal draft and there’s definitely a difference in our boats. My forward space above the keel is 13” wide and more than 10” deep. I have two group 29s in there as a house bank.

[Chili Palmer]

Originally Posted by OldManMirage

I may have to re-think the AGM's on their side. I have researched a bit more and it "seems" they are designed to orient that way if needed ?

I've searched through some of posts on CF.

I may have to make another Thread re-asking that question.

Anyone have opinions on this ?

Just an FYI - I have been in the offroading/4x4 scene for decades and LOTS of offroad guys mount their AGM batteries on their sides. I've never heard of any issues, even with all the beating the vehicles take.

[Thebaysailor]

I just bought four SOK Lithium bats at 12v 206Ah ea. Cost was less that $1000 per unit. Based on your cost estimate for the AGM the SOK at 206 Ah is actually cheaper, and, important to your problem, much lighter.
You could easily place one SOK 206 at the quarter berth to replace two AGM bats. SOK weighs 46 lbs. This bat is also in a Marine Case and serviceable.

Take a look at Will Prose on Youtube for a complete tear-down of many Lithium bats and his comments on each. Very good info.

If you do the math, DOD, charge time, life cycles, the Lithium is half the cost of any FLA bat.
Victron Energy makes great product that will allow you to integrate Lithium into your charger system with little or no modification.

[scottburch]

I have swapped out our AGM batteries for Lithium and love it. As far as the space, we have 3 of these in our space standing up, but they should lay down fine. And, I think they are only about 7 inches in that direction.

The only downside is that the sides are not flat, so you would have to deal with a curved bottom.

https://battlebornbatteries.com/prod...e-gc3-battery/

A bit expensive, but, at least for us, well worth the price.

[OldManMirage]

Yeah, honestly I am still waffling about the Lithiums. One side of me says "spend the money, get the high tech solution, everybody's going that way." The other side says "it's too expensive, be conservative, do what works for you."

Fortunately I don't have to make the decision today.

I'll keep researching. And following any similar threads that pop up here on CF so I can glean info from other people !

[ranger58sb]

Originally Posted by PaulCrawhorn

There are three AGM manufacturers worth considering for true deep cycle use in North America.

Lifeline, Odyssey and Northstar.

One imported Chinese brand I forget but not as good.

Full River, maybe?

Oasis Firefly Carbon Foam is another to add to the list of "premium" (?) AGMs. Although some other threads suggest maybe some recent QC problems with manufacturing in India. CF member Bruce Schwab/Ocean Planets could probably speak to that...

-Chris

[PaulCrawhorn]

Fullriver is shipped from China.

But yes, if they are cheaper per Ah than those three acceptable

Fireflies are excellent, but special qualities you really are paying a lot for, starts to make LFP more tempting

and yes, confirm the seller is in Bruce's network, do not buy direct.

[OldManMirage]

Something I was considering for now that would give me some idea of how well Lithium batteries might perform for me is to simply get a pair of 100AH that will fit in my existing boxes. They are built in by the manufacturer in the engine room. Group 24 size batteries will fit. I can adust my solar regulator to the appropriate voltages.

My question is - would a bank of 2 Lithium 100AH batteries be ok to start my Yanmar 20HP ? I believe it would be.

I've read similar threads, but I'd appreciate a recap of opinions ?

Thanks in advance.

[PaulCrawhorn]

Absolutely yes, if you were talking bare cells + an appropriate BMS or a bypass switch.

However, if going with drop-in units, your current output will be limited by the BMS chosen by the assembler ("maker"). Some don't even want you to connect in parallel (too much).

No way to bypass the BMS limitation either. No way to see the per-cell/group voltages if balance issues arise. So you would need to contact knowledgeable pre-sales tech support at the maker of each model you are considering, to ask these questions.

Or just DIY a pack out of 4x 200+ Ah cells, it is not rocket science. Until you start getting conflicting opinions from members here and go down the research rabbit hole. Choosing a good BMS and designing wiring that lets you bypass its current limits for cranking your engine will be the biggest issue, but just a "medium" challenge.

[OldManMirage]

Huh. I swear I'm not against technology but that reply just makes me want to go back to thinking about AGM's ! Lol.

Its really not much more complicated than what I have with a solar regulator, but it does add another level of complexity to a system that already has enough things that can go wrong. Add in the fact that I'm trying to keep costs down as much as possible and it gets even more problematical.

I'll keep thinking about the options. Maybe something new will come along before I have to make the final decision.