House Batteries

[BayBum]

We have 4 house batteries that may be coming to the end of their useful life. I recently replaced my starting battery with a Life Line battery and am considering the Life Line GPL-31T AGM Deep Cycle. But Amazon has the Renogy 12volt,100 amp hour battery for $189 each which is less than 1/2 the price of a Life Line. We usually stay out for 3-7 days at a time and most of the amperage draw is from the frig. I have a Honda generator to run the on board battery charger as needed.
Any thoughts or recommendations are appreciated.

Greg
2000 Camano

[DavidM]

I now have three years of service on a pair of the Renogy batteries mentioned above, and still going strong.

David

[guy with a boat]

My experience has been that, while you pay more for Lifelines, you get more. It's not a higher price for the same product. The design, build quality, quality control, documentation and customer support are all better than with the less expensive batteries.


Its your call whether the better product is worth the extra cost, but it is for us. If you have programmable charging and follow the Lifeline charging recommendations, the Lifeline batts can last a very long time. We replaced ours in year 7, with lots and lots of use.

[tiltrider1]

For house use I am finding LiFePO4 batteries to be the best long term value. Only recently have they become price competitive.

Buying an ok LiFePO4 batter is pretty easy. Buying a great one is a little more difficult.

If you are buying a LiFePO4, make sure the BMS matches the Ah rating on the battery. For instance, if you are looking at 100Ah renology, make sure the BMS is rated for 100Ah.

Second thing to look for is both high temp and low temp cut off. Charging and discharging outside the batteries temperature range can do serious damage. Know the operating range of the battery. You don’t want it turning off just because the temperature dropped to 32 degrees. I have seen batteries out there with a low range as cold as -4 degrees F.

Make sure you know if the battery is made from A grade or B or C grade cells. I see no issue with B grade Cells but if you are paying top dollar you should be getting A grade.

Stay away from any LiFePO4 that lists 2,000 cycles or less, has a warranty of less than 3 years or lists an odd Ah figure like 45, 95, 200. These could very possibly be made up from recycled 50, 120, 260 cells.

[Max1]

I have gone to a combination of Lead-Lithium for my house bank.

The lithium's do all the heavy lifting.
The lead's are there to protect the lithium from the top and bottom end.

The lithium's each have their own battery monitoring system(BMS).

Power comes mostly from solar, but I also have a a blue-Sea ACR that will charge the house bank if the engine is running.

Current setup is 2 100Ah Lithium, 1 200AH lithium, and 2 100Ah AGM Deep Cycle batteries.

In 2 years living on the water in the summer, we have opted out of the extra cost of shore-power. Solar provides us with all the power we need, and have not run our genny at all even though we keep one on the boat as a back-up.

[ranger58sb]

Originally Posted by BayBum

We have 4 house batteries that may be coming to the end of their useful life. I recently replaced my starting battery with a Life Line battery and am considering the Life Line GPL-31T AGM Deep Cycle. But Amazon has the Renogy 12volt,100 amp hour battery for $189 each which is less than 1/2 the price of a Life Line.

Looks for Rod Collins' (CMS here, Mainesail on Cruisers Forum) comments about Renogy, both products and company.

I'd stay with the Lifeline 125-Ah G31s.

-Chris

[guy with a boat]

Originally Posted by Max1

I have gone to a combination of Lead-Lithium for my house bank.

The lithium's do all the heavy lifting.
The lead's are there to protect the lithium from the top and bottom end.

The lithium's each have their own battery monitoring system(BMS).

Power comes mostly from solar, but I also have a a blue-Sea ACR that will charge the house bank if the engine is running.

Current setup is 2 100Ah Lithium, 1 200AH lithium, and 2 100Ah AGM Deep Cycle batteries.

In 2 years living on the water in the summer, we have opted out of the extra cost of shore-power. Solar provides us with all the power we need, and have not run our genny at all even though we keep one on the boat as a back-up.

Can you explain your setup? Are you running the two types (and 3 sizes) of batteries in the same bank and with the same charging?

[janice142]

Also re the lithium batteries... I thought I read that marine insurers for boats in the United States were not insuring 99% of lithium batts. The only ones passing the insurance test were manufactured here in the United States, with charging systems made in the US, and installed by qualified/approved lithium battery professionals. Has that situation changed?

[Ken E.]

My house bank is eight Interstate 6v LA golf cart batteries, four pairs at 12 volts. About 1000 ah. They are 9 years old and just returned from 3 months in SE AK, mostly on the hook. They still function fine but I'm changing them preemptively. I've ordered Interstate AGM'S of the same size which I'll put in next week. I hope the next ones are just as good.

[Max1]

Originally Posted by guy with a boat

Can you explain your setup? Are you running the two types (and 3 sizes) of batteries in the same bank and with the same charging?

It's nothing complicated. All batteries are hooked up in parallel, with the solar connectors going to opposite ends of the parallel bank. That way the charge is forced to go through the entire bank. Similarly, the main connections to the house fuse panel also comes from opposite sides of the bank.

The most important thing of a lead-lithium combination, is:
One, make sure both batteries are at the same charge rate when connecting in parallel. For me, this only happens in the spring when I'm bringing my house batteries back from Storage in my basement over the winter. I like to set up my batteries before connecting, by bringing the lithium to full charge am letting them rest. At this point they should be around 13.2 to 13.4 volts or similar. At the same time I will charge my leads until they reach float charge. At that point all the batteries can be connected at the same time.

The second most important thing is to make sure that the lithiums have built in BMS systems. The BMS is there to make sure that the lithiums are disconnected when voltage reaches maximum charge. At that point the leads can take over and accept any charge from the solar charge controller, which trickles the charge down when it reaches about 14.6 volts. (Solar MPPT controller is configured for Lead batts). Similarly if, and though I've never had this happen yet in 2 years of boating, the lithiums drop below 12.2, the BMS will disconnect them and the leads will then take over. Like I said, in 2 years of boating I've never dropped below 12.8 volts given my current bank setup and consumption.

I learned all this from a video on youtube, can't remember the name of the couple, but they live on a sailboat have a series of electronics tutorial videos, one of them is how to connect Lead-lithium to your house bank.

[Jeff F]

Originally Posted by Max1

The second most important thing is to make sure that the lithiums have built in BMS systems. The BMS is there to make sure that the lithiums are disconnected when voltage reaches maximum charge.

Um, no.

There is lots of solid advice here. Let's not ruin things by propagating YouTube nonsense.

[Simi 60]

Originally Posted by Max1

It's nothing complicated. All batteries are hooked up in parallel, with the solar connectors going to opposite ends of the parallel bank. That way the charge is forced to go through the entire bank. Similarly, the main connections to the house fuse panel also comes from opposite sides of the bank.

The most important thing of a lead-lithium combination, is:
One, make sure both batteries are at the same charge rate when connecting in parallel. For me, this only happens in the spring when I'm bringing my house batteries back from Storage in my basement over the winter. I like to set up my batteries before connecting, by bringing the lithium to full charge am letting them rest. At this point they should be around 13.2 to 13.4 volts or similar. At the same time I will charge my leads until they reach float charge. At that point all the batteries can be connected at the same time.

The second most important thing is to make sure that the lithiums have built in BMS systems. The BMS is there to make sure that the lithiums are disconnected when voltage reaches maximum charge. At that point the leads can take over and accept any charge from the solar charge controller, which trickles the charge down when it reaches about 14.6 volts. (Solar MPPT controller is configured for Lead batts). Similarly if, and though I've never had this happen yet in 2 years of boating, the lithiums drop below 12.2, the BMS will disconnect them and the leads will then take over. Like I said, in 2 years of boating I've never dropped below 12.8 volts given my current bank setup and consumption.

I learned all this from a video on youtube, can't remember the name of the couple, but they live on a sailboat have a series of electronics tutorial videos, one of them is how to connect Lead-lithium to your house bank.

Scary stuff
No way would I be doing that and letting the BMS to disconnect
Programme charger or disconnect
BMS disconect is a failsafe that will hopefully never gone into play

[guy with a boat]

Originally Posted by Simi 60

Scary stuff
No way would I be doing that and letting the BMS to disconnect
Programme charger or disconnect
BMS disconect is a failsafe that will hopefully never gone into play

Scary is right. Apparently the engineering here is over my head, because I would have bet that no one would actually run that way.

[guy with a boat]

Originally Posted by Jeff F

Um, no.

There is lots of solid advice here. Let's not ruin things by propagating YouTube nonsense.

Jeff F; are you suggesting no BMS is required, or just that it doesn’t need to be built in to each battery? Or something else and I missed your point? Not seeing the nonsense part.

[Simi 60]

Originally Posted by Simi 60

Scary stuff
No way would I be doing that and letting the BMS to disconnect
Programme charger or disconnect
BMS disconect is a failsafe that will hopefully never gone into play

Gee, shite spolling on my part
Try again

No way would I be doing that and letting the BMS do disconnect
Programme charger to disconnect
BMS disconnect is a failsafe that will hopefully never come into play

[Jeff F]

Originally Posted by guy with a boat

Jeff F; are you suggesting no BMS is required, or just that it doesn’t need to be built in to each battery? Or something else and I missed your point? Not seeing the nonsense part.

The idea that the BMS exists in order to stop the charging, and that it's normal or acceptable to charge until the BMS is triggered.

[Delta Riverat]

The BMS insures that the battery is not over charged or under drawn. Also will shut down on over temp and sometimes under temp. Balances individual cells as they may come to full charge before others and are cut off as the others come up.

[guy with a boat]

Originally Posted by Jeff F

The idea that the BMS exists in order to stop the charging, and that it's normal or acceptable to charge until the BMS is triggered.

Ok, then I’m with you. I didn’t read it that way the first time but I agree with your point.

There are some risks associated with designing your electrical system based on what you saw on youtube.

[Simi 60]

Originally Posted by Jeff F

The idea that the BMS exists in order to stop the charging, and that it's normal or acceptable to charge until the BMS is triggered.

I still don't like that.

All the research I have read says ....

BMS is for cutoff at low voltage
Charger should be configured to shutoff at high voltage
BMS is a secondary failsafe for top end charging if charger parameters fail.

I imagine a BMS probably has only so many one-off cycles in it
The less activations the more reliability.

[SteveK]

You are right and he is right. In the two years of research I found it depends on whose LFP you are looking at, and when, what year., what latest upgrade. The latest appears to be low cut off, no charging allowed if too cold and when full, stop charging.
Then there are the alternators that can burn up with the full speed ahead recharge demand of LFP, then a sudden stop charging. Bring on DC2DC chargers. Nevers ends.

Bottom line once you buy whatever battery, get familiar with what that battery wants.
My LFP actually talk to one another with ethernet cable and if one or more is not charged at the same level the others refuse charge until they are all even. The BMS talk to each other.

My inverter charger LFP profile has float profile controled by the BMS, not inverter. Often I see no current and then depends on draw have seen 1,2,3 amps up to mid teens.
Always 13.5v maintained.