Need a little more battery capacity

[crayiii]

We currently have two Lifeline 8d AGM batteries in addition to three start batteries (two mains, one generator) on our cat.

Our charging sources are 900 watts of solar, 800 watts of wind, alternators, and AC chargers.

Most of the time we're okay but there are a couple senerios where we get low. Downwind overnight sailing, rainy windless overnight anchorages. We then run the generator but would like to avoid that as much as possible.

We're full-time cruisers with too much refrigeration so overnight draws can sometimes hurt the batteries.

I talked with a number of lithium dealer/installers and have concluded that it just isn't a fit for us at this time.

We need maybe another 100ah. I looked at replacing our two 8d's with four Lifeline 6v but was surprised that they are not a stocked item in most of the Caribbean islands where we've looked.

I would love to switch to the Firefly batteries but again, finding them seems impossible.

Are there 8d batteries with more capacity than the lifelines? Maybe we can add the start batteries to the bank? Any suggestions?

[David M]

You will want the same type of battery on the same circuit. Not good to mix, lead-acid, lithium, etc together.

Do you have the room somewhere for more 8D's?

[StuM]

I doubt that you will find any 8D with more the 255 Ah


With two of then you've only got about 250 Ah usable if you want them to last.



I'd try for more than another 100 Ah,. With that amount of solar and wind, you could possibly sell the generator and replace it with another two 8Ds giving you 500 Ah usable

[ranger58sb]

Originally Posted by crayiii

We need maybe another 100ah. I looked at replacing our two 8d's with four Lifeline 6v but was surprised that they are not a stocked item in most of the Caribbean islands where we've looked.

I would love to switch to the Firefly batteries but again, finding them seems impossible.

I THINK I remember that six 6V GC2s will fit in the same horizontal footprint of two 8Ds. If true, that'd be about 660Ah for the 6Vs versus about 490 Ah for the 8Ds.

Then there are the taller 6V options, too, L16s and so foth if you have vertical clearance.

If you can't find Lifelines, you can probably at least find some decent FLA GC2s... assuming you have easy access to service them... or can install a watering system...

-Chris

[David M]

StuM, he wants to add more capacity. Adding an 8D or two is doing exactly that.

[john61ct]

Originally Posted by crayiii

We need maybe another 100ah. I looked at replacing our two 8d's with four Lifeline 6v but was surprised that they are not a stocked item in most of the Caribbean islands where we've looked

And Lifeline 8Ds are?

What 6V GCs are commonly available?

Could you go to flooded? last longer and usually better value.

Assuming lead of equivalent quality, Ah capacity is a function of weight and size, so more space is required.

Unless more fundamental design changes along these lines:


> Maybe we can add the start batteries to the bank?

Swap out the existing ones for additional 8Ds, join to House via adjustable LVC, same as an ACR/VSR but lower "isolation" setpoint to prevent ability to crank from being threatened by House loads.

A related but less controversial arrangement, just doesn't go as far solving your problem, is converting the "dedicated Starters" to be a Reserve bank.

Recent discussion here http://www.cruisersforum.com/forums/...ml#post2982422

But consider allocating more space for adding another 8D for now, certainly the simplest most mainstream option.

[RickG]

Budget Marine sells Lifelines at their Caribbean locations.

We use 7 Fireflys and love them on our Caribbean homed monohull. Given your on a cruising cat, I would definitely consider lower weight LiFePO4s; we installed our Fireflys two years ago, but would go with Lithium now.

Relion has distributors on Puerto Rico and Grenada for their Lithiums.

Cheers, RickG

[tkeithlu]

Perhaps think about approaching this question from the energy end. If you went to one type for all your batteries, and then added your starter batteries to the mix, a larger alternator could charge everything, and so could the genset. At low use, solar or wind could help. You might not need to add batteries. But.....
1. I'd want to keep the genset starter battery isolated or able to be selectively added to the system, because you need it to start the genset if everything goes dead.
2. The size of the alternator(s) becomes critical, because if just about everything is down and you insert a 60 amp alternator in there, you're going to burn it out. I'd want sophisticated voltage regulators/chargers (Balmars) on the main engines.

There's an advantage to being able to cross sources of energy and isolate or cross batteries. It gives you more options "in," and more options "out."

I have an isolated battery behind my instument panel, which I can charge off any of several sources (main alternator, shore, genset, or just attach to the charged house batteries). It's there because if I get flooded, all my house batteries will be flooded with seawater, and then how do I call for help? It's also possible to put my two starter batteries in parallel or even series (24 volts flies a starter!), or add them to the house. Having a rotary switch to the panel voltmeter lets me check on each battery in turn.

[Nicholson58]

Originally Posted by crayiii

We currently have two Lifeline 8d AGM batteries in addition to three start batteries (two mains, one generator) on our cat.

Our charging sources are 900 watts of solar, 800 watts of wind, alternators, and AC chargers.

Most of the time we're okay but there are a couple senerios where wej get low. Downwind overnight sailing, rainy windless overnight anchorages. We then run the generator but would like to avoid that as much as possible.

We're full-time cruisers with too much refrigeration so overnight draws can sometimes hurt the batteries.

I talked with a number of lithium dealer/installers and have concluded that it just isn't a fit for us at this time.

We need maybe another 100ah. I looked at replacing our two 8d's with four Lifeline 6v but was surprised that they are not a stocked item in most of the Caribbean islands where we've looked.

I would love to switch to the Firefly batteries but again, finding them seems impossible.

Are there 8d batteries with more capacity than the lifelines? Maybe we can add the start batteries to the bank? Any suggestions?

We determined LI was not for us too. Too much had to change, too much system reprogramming and BMS would require a lot of wiring.

Firefly is not generally stocked. We ordered direct and had them delivered to a freight forwarder in Florida to meet the boat in Trinidad. They were waiting for us at the Power Boats boater shop last November. Shipping overseas is by volume, not weight. Six X 4 volt 450 AH = 24 VDC. We have one season on these now. The first season was great. Caution. All big high recharge rate batteries such as these may overload an alternator not rated for continuous full load output could get fried. Use your alternator charge controller to limit the rate. We set the Balmar to 80% after replacing the alternator.