It turns out that 4 years ago i purchased a giant AGM with a pro rata 5 year warranty. The 1st unit made 2.5 years and the way the warranty works is the customer pays the relative portion of the replacement. Ie I paid half of the cost of the replacement. So now the replacement is kaput and you guessed it the replacement cost is actually more than buying a new unit because you have to pay pro rata on the recommendation retail price not the discount price. If you want to fool around it's a sort of plausible path because you get 2 mediocre units for the price of 1.5 mediocre units. I think I will go back to quality ( century, Trojan, interstate) flooded lead acid for the next round of batteries, all the battery enclosures are easily accessed so the task of topping up the water is ok

Tricky warranty. Over a 5 year period I went through three pairs of 150ah AGM. No good explanation as to why, They started out OK, one year later could only hold half charge. Rather than argue I just binned them.
With trepidation I switched to 2 x 150AH Lithium. And more than a year later they are as good as they were new. Much lighter and smaller too. Ive glued temperature sensors on them connected to my Trek. That was the worry but so far so good.
Consider Lithium Woko but good ones and good temperature monitoring.

I would have to agree with trek lithium is worth a look
My current boat came with lithium 400ah winston cells they where 14 years old when I replaced them last year
Replaced them with 2x 300ah packs and bms from ev power australia cost a bit more than the stuff on ebay but think the quality and customer service is worth it and if the last another 14 years it will still work out cheaper than lead acid
Golf cart wet cell lead acids are good to My father gets 8 years out of a set of trojens

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Trek said..
Tricky warranty. Over a 5 year period I went through three pairs of 150ah AGM. No good explanation as to why, They started out OK, one year later could only hold half charge. Rather than argue I just binned them.
With trepidation I switched to 2 x 150AH Lithium. And more than a year later they are as good as they were new. Much lighter and smaller too. Ive glued temperature sensors on them connected to my Trek. That was the worry but so far so good.
Consider Lithium Woko but good ones and good temperature monitoring.

Although temperature monitoring is interesting I would suggest that if a short happens or the BMS ceases to work then fire and thermal runaway will happen too soon thereafter for any intervention.

For those occasions when you are onboard a mere temp sensor needs to be accompanied by an alarm. Obviously every positive connection to it also needs fusing.

As regards eBay lithium batteries versus "good quality" ones I have noticed that some claim only 2000 or 3000 cycles whereas others claim 5,000. It's not just eBay versus exorbitantly priced brick and mortar stores. It is very common to place used cells in these batteries to save money. Presumably it's the 2000 cycle batteries cells that are used or matched with each other to a large tolerance rather than new. Then of course there are retailers who just lie.

I considered lithium, I'm not concerned about the fire risk, I think it's a bit of a beat up, it happens but like LPG on a boat limited instances get bad press. I don't think lithium or battery technology for that matter has made its next major advance as yet, it's not hard to imagine that a game changer is just around the corner, I'm sure if you shelled out for say a victron AGM you would get a better run than the bargain variety & the maintenance free lead acids are ridiculous, its not maintenance free you just can't do the maintenance. Between the two boats and the work Ute I have eight z70/ 100ah units and for the present at least, the 100 year old technology is still viable

I'm going on 6 years with my Giant AGM's Woko, they're still good (touch wood!). Presuming you haven't consistently run yours down below 50%, I guess you got some dodgy ones and maybe the Giant's quality control isn't great. Good to know that it may be a crap shoot when I come to replace them, as I would have considered the Giants again. Let us know what you end up going with?

I've heard of phones, scooters,hoverboards ect catching fire from being left on the charger but I have yet to hear of a deep cycle setup in a boat or RV, off grid system with any issues with lithium, I could be wrong though

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bullrout said..
I've heard of phones, scooters,hoverboards ect catching fire from being left on the charger but I have yet to hear of a deep cycle setup in a boat or RV, off grid system with any issues with lithium, I could be wrong though

I would be amazed if there hadn't been any problems given the instances of everything else including cars which have serious runaway events. I have a friend with a Battery World franchise and he says that shops have burned to the ground because of lithium batteries. Plenty of boats burn to the waterline and I saw one from a distance while I was in the Whitsundays a couple of months ago. I was never able to ascertain the cause. As I have mentioned on here previously the YouTubers Barefoot Doctors also had a new 50-foot Leopard catamaran burn and sink but but they are prevented from commenting by insurance, manufacturer or litigation gag constraints.

I have a fairly new solar charged lithium in my trailer sailer with a smoke detector directly above it. The thing does make me nervous however and I will not sleep in the best bunk in the boat which has its fairly restricted access right above the battery compartment.

I decided I would like a temperature alarm last night and spent a while on the web looking for one. There are a number of inexpensive such alarms marketed as fridge freezer alarms although encompassing a wide enough temperature range for this purpose.
Unfortunately the loudness of the alarm is an issue which has been brought up by reviews on a number of the products. As one might expect with a product warning of a non life threatening event they seem to be a fairly gentle alarms which could be easily overlooked while sleeping or not heard by hearing impaired oldies like me if not in the cabin.

The advantages of lithium batteries apart from the potential for thermal runaway make their adoption a no-brainer.

Anyone know of a reasonably priced alarm with a screamer?

Actually Jules yes now that you mention it, the EV fires and ferocious too I forgot about them, I might stick with the gel cells lol

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bullrout said..
Actually Jules yes now that you mention it, the EV fires and ferocious too I forgot about them, I might stick with the gel cells lol

I'm rather inconsistent with risks. Tore the gas system out of one boat but installed lithium in the other :-)

Julesmoto you are absolutely right that once that thermal runaway starts is nearly impossible to stop a lithium battery fire.

The purpose of my temperature sensing is to disconnect the batteries automatically if they exceed 40 Deg C and message me so I can check whats up. Using four of these www.trektransponder.com.au/shop/marine-power-relay/ 40 Deg C might be a bit low but being cautious.

At least if there's a fault with boat electrics over or undercharging causing the risk this might save things. And and I will know to run and check!!

You all do realise don't you that Lithium Ion and Lithium iron are two different chemistries don't you??
Lithium Ion is most common in cars and phones and power tools etc, while Lithium Iron is what is used in boats and some RV's.

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UncleBob said..
You all do realise don't you that Lithium Ion and Lithium iron are two different chemistries don't you??
Lithium Ion is most common in cars and phones and power tools etc, while Lithium Iron is what is used in boats and some RV's.

It's lithium iron phosphate actually and I believe they are the most prevalent type in EVs now as well with lithium ion being very old technology.
Whilst lithium iron phosphate is more stable it's still goes off like a fireworks factory if destabilized.

Don't forget that all these things are made in China and the BMS upon which they rely to remain stable is a circuit board sitting right above the (usually gel pouch) cells inside the casing. Like any circuit board it can malfunction or even short and that is quite a part from the scores of little soldered joints and wires linking the gel pouches together neatly packaged in a sealed plastic box looking like a standard AGM or sealed lead acid battery. It only takes one of the many cells to be overcharged, overheated by use, ruptured or otherwise destabilized to set the whole lot off.

At least that is my understanding. Please correct me if I am wrong.

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What happens when you are towing with a Tesla and it slips down the ramp into the drink?
Watch this one from 1:55.

Something to ponder.

Yep plenty scary. An unlikely event but catastrophic when it occurs. Kind of like why I have no time for nuclear power.
I appreciate that Trek has designed a very high quality system but am I prepared to take the risk of such an extremely unlikely event occurring while I am not on the boat. My worry is when I and my family are sleeping on the boat and to a lesser extent when we are sailing it and would have to jump overboard.
I think items such as following might give us a sporting chance not because they are Wi-Fi enabled as I probably wouldn't hear my phone while sailing but for the audible alarm. They certainly are cheap enough.

au.banggood.com/Tuya-WiFi-Temperature-Humidity-Sensor-With-LCD-Display-Smart-Life-Remote-Monitor-Indoor-Thermometer-Hygrometer-Via-Google-Alexa-p-1981057.html#popupviewPicture


www.ebay.com.au/itm/134528836531?mkcid=16&mkevt=1&mkrid=705-154756-20017-0&ssspo=sayh0um0thg&

www.ebay.com.au/itm/374950565734?mkcid=16&mkevt=1&mkrid=705-154756-20017-0&ssspo=MEfw47v8S0e&sssrc=2349624&ssuid=OSEcmjxFQbe&var=&widget_ver=artemis&media=MORE

Audible alarm absolutely important. Especially since most people these days have their phone on silent!

Hence I have one of these www.trektransponder.com.au/shop/loud-acoustic-alarm-on-baord/

When sleeping with family on board aside from lithium batteries there's smoke, fume and bilge flooding risk so you need audible alert for those too. I don't have a gas risk, I got rid of it from my boat rather than risk it. Funny how we all worry about different things :-) I don't like LPG but am willing to try Lithium Batteries. Probably not logical!!

Agree about WiFi, its unreliable for alarms and monitoring. Too many failure possibilities. For the record to clarify above the Trek alarms dont use Wi-Fi and all work any time regardless of a 4G connection, that's only for when you are not on the boat.

To stay on the subject of the thread that system will also sound audible alarm if batteries are too low in voltage which will improve their life of you halt the discharging - except maybe for Lithium's. I need to read more. :-)

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woko said..
It turns out that 4 years ago i purchased a giant AGM with a pro rata 5 year warranty. The 1st unit made 2.5 years and the way the warranty works is the customer pays the relative portion of the replacement. Ie I paid half of the cost of the replacement. So now the replacement is kaput and you guessed it the replacement cost is actually more than buying a new unit because you have to pay pro rata on the recommendation retail price not the discount price. If you want to fool around it's a sort of plausible path because you get 2 mediocre units for the price of 1.5 mediocre units. I think I will go back to quality ( century, Trojan, interstate) flooded lead acid for the next round of batteries, all the battery enclosures are easily accessed so the task of topping up the water is ok

I have Lifeline AGM's, installed in 2018 before I bought the boat, I would replace with the same when the time comes. Not cheap but good quality.

I know a few marine sparkies, my son is one, his boss is not very keen on Lithium, he will install them but won't supply them.

Another marine sparky I know loves lithium, does plenty of change overs from AGM, supply and install, he told me the chemistry in the LiPO4 lithium makes it impossible for them to ignite, lots of smoke but no fire. I am not sure if that is correct or not.

Another sparky I know who is not marine sparky but has had a lot of experience manufacturing batteries and also designing and installing remote off grid mobile phone towers for 20 or 30 years, will not put Lithium in his own boat.

ps I have gas onboard, in an isolated locker, with a solenoid valve attached to a sniffer and two manual mechanical shut off valves. I turn it on when needed and off when it's not. I have to turn on two switches, wait for the all clear from the sniffer and open two valves to operate, I think that's safe.

I've had 8 VariCore 3.2V 280Ah lifepo4 batteries as 2P4S=TwoParallelCells/FourSeriesCells (560 Ah) running for over 2 years & couldn't be happier!!
My only gas is mounted outside for the BBQ.

I'm about to install a temperature monitor for them soon but other projects keep popping up!!

This is how they look from 8.30 this morning until now (9.15) with a fridge & freezer as well as my Pi4 running full time. I also have 3 fans running when I'm not on the boat.
When I'm using the boat I have the 12v hot water element wired to come on when the batteries are fully charged so I'm not wasting the free solar power.




Here's a comparison with the AGMs I got rid of.

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cammd said..

woko said..
It turns out that 4 years ago i purchased a giant AGM with a pro rata 5 year warranty. The 1st unit made 2.5 years and the way the warranty works is the customer pays the relative portion of the replacement. Ie I paid half of the cost of the replacement. So now the replacement is kaput and you guessed it the replacement cost is actually more than buying a new unit because you have to pay pro rata on the recommendation retail price not the discount price. If you want to fool around it's a sort of plausible path because you get 2 mediocre units for the price of 1.5 mediocre units. I think I will go back to quality ( century, Trojan, interstate) flooded lead acid for the next round of batteries, all the battery enclosures are easily accessed so the task of topping up the water is ok

I have Lifeline AGM's, installed in 2018 before I bought the boat, I would replace with the same when the time comes. Not cheap but good quality.

I know a few marine sparkies, my son is one, his boss is not very keen on Lithium, he will install them but won't supply them.

Another marine sparky I know loves lithium, does plenty of change overs from AGM, supply and install, he told me the chemistry in the LiPO4 lithium makes it impossible for them to ignite, lots of smoke but no fire. I am not sure if that is correct or not.

Another sparky I know who is not marine sparky but has had a lot of experience manufacturing batteries and also designing and installing remote off grid mobile phone towers for 20 or 30 years, will not put Lithium in his own boat.

ps I have gas onboard, in an isolated locker, with a solenoid valve attached to a sniffer and two manual mechanical shut off valves. I turn it on when needed and off when it's not. I have to turn on two switches, wait for the all clear from the sniffer and open two valves to operate, I think that's safe.

Those lifeline AGM units make the victron ones look cheap ! USA made mil spec you pay for what you get, I see they have the pro rata warranty as well but with a cost free replacement in the first year.

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Lazzz said..
I've had 8 VariCore 3.2V 280Ah lifepo4 batteries as 2P4S=TwoParallelCells/FourSeriesCells (560 Ah) running for over 2 years & couldn't be happier!!

Just realised that pricing for standalone 3.2V cells has dropped in the last year or so. The cool thing about the 3.2V cells is that you get them into nooks and crannies.

Out of interest Lazz what BMS did you use ? Did you have a separate BMS for each string and did you use a parallel module ?

Andrew

I'm considering changing from my current lead-acid storage (120 Ahr house, 90 Ahr engine) to LiFePO4.

For those who have made the switch from lead-acid to Lithium for their house batteries, what did you use as the engine start battery? And if you have LiFePO4 for the house battery but lead-acid for the engine start battery, how did you deal with the different charging requirements?

Cheers,
Kinora

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Andrew68 said..

Just realised that pricing for standalone 3.2V cells has dropped in the last year or so. The cool thing about the 3.2V cells is that you get them into nooks and crannies.

Out of interest Lazz what BMS did you use ? Did you have a separate BMS for each string and did you use a parallel module ?

Andrew

I'm using a Daly BMS LiFePO4 4S 12V250A Common port with Balance, UART & Bluetooth - No problems so far!!

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Kinora said..
I'm considering changing from my current lead-acid storage (120 Ahr house, 90 Ahr engine) to LiFePO4.

For those who have made the switch from lead-acid to Lithium for their house batteries, what did you use as the engine start battery? And if you have LiFePO4 for the house battery but lead-acid for the engine start battery, how did you deal with the different charging requirements?

Cheers,
Kinora

I have a lead acid for the start battery and it, & my LiFePO4 house bank, run through a Redarc BCDC 1250D Dual Input Multi-Stage Charger (Google it).
This thing was a game changer for me as it controls the solar & alternator inputs to charge the start & house batteries. It was a bit pricey but well worth the outlay.

This (untidy) diagram might help explain things.

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Lazzz said..

I have a lead acid for the start battery and it, & my LiFePO4 house bank, run through a Redarc BCDC 1250D Dual Input Multi-Stage Charger

This thing was a game changer for me as it controls the solar & alternator inputs to charge the start & house batteries. It was a bit pricey but well worth the outlay.

This (untidy) diagram might help explain things.

Nice Diagram. So your starter battery is still directly connected to the alternator in a standard configuration. The Redarc DC-DC charger indirectly charges the lithium batteries. Its cool that it can also back charge the starter battery. Only one solar panel is connected to the REDARC unit with the others connected directly the house batteries via MPPT chargers. It's a nice set and forget configuration.

Kinora, I was planning a similar set up with except I was going to use a Victron DC-DC charger without the REDARC integration function. I don't think I need the ability to to top up the start battery from solar as it will hold charge from routine use. I currently have a MOSFET charge splitter and might continue to use that just on the start battery for even more separation.

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Lazzz said..

Andrew68 said..

Just realised that pricing for standalone 3.2V cells has dropped in the last year or so. The cool thing about the 3.2V cells is that you get them into nooks and crannies.

Out of interest Lazz what BMS did you use ? Did you have a separate BMS for each string and did you use a parallel module ?

Andrew

I'm using a Daly BMS LiFePO4 4S 12V250A Common port with Balance, UART & Bluetooth - No problems so far!!

Kinora said..
I'm considering changing from my current lead-acid storage (120 Ahr house, 90 Ahr engine) to LiFePO4.

For those who have made the switch from lead-acid to Lithium for their house batteries, what did you use as the engine start battery? And if you have LiFePO4 for the house battery but lead-acid for the engine start battery, how did you deal with the different charging requirements?

Cheers,
Kinora

I have a lead acid for the start battery and it, & my LiFePO4 house bank, run through a Redarc BCDC 1250D Dual Input Multi-Stage Charger (Google it).
This thing was a game changer for me as it controls the solar & alternator inputs to charge the start & house batteries. It was a bit pricey but well worth the outlay.

This (untidy) diagram might help explain things.

Many thanks, Lazz!

K.

Select to expand quote

Andrew68 said..

Lazzz said..

I have a lead acid for the start battery and it, & my LiFePO4 house bank, run through a Redarc BCDC 1250D Dual Input Multi-Stage Charger

This thing was a game changer for me as it controls the solar & alternator inputs to charge the start & house batteries. It was a bit pricey but well worth the outlay.

This (untidy) diagram might help explain things.

Nice Diagram. So your starter battery is still directly connected to the alternator in a standard configuration. The Redarc DC-DC charger indirectly charges the lithium batteries. Its cool that it can also back charge the starter battery. Only one solar panel is connected to the REDARC unit with the others connected directly the house batteries via MPPT chargers. It's a nice set and forget configuration.

Kinora, I was planning a similar set up with except I was going to use a Victron DC-DC charger without the REDARC integration function. I don't think I need the ability to to top up the start battery from solar as it will hold charge from routine use. I currently have a MOSFET charge splitter and might continue to use that just on the start battery for even more separation.

Thanks, Andrew68. Kinora had a MOSFET splitter but it was dead by the time I bought the boat. I had 3 x 55 W panels installed before the delivery with the panels charging the house battery, the alternator charging the start battery and a VSR between the 2 so the panels can charge the start battery when the house battery is full. I think I can just replace the VSR with a DC-DC charger and swap the 120 Ahr lead-acid house battery for 2 x 100 Ahr LiFePO4 and get nearly triple the storage. The only thing that would have to go would be the switch that allows the house and start batteries to be put in parallel for ~15 seconds in the event the start battery is flattened.

K.

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Kinora said..

The only thing that would have to go would be the switch that allows the house and start batteries to be put in parallel for ~15 seconds in the event the start battery is flattened.

K.

I still have a switch so that I can use the house batteries to start the engine if the start battery dies or use the start battery to run the house if needed.
Only used it once.

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Lazzz said..

Kinora said..

The only thing that would have to go would be the switch that allows the house and start batteries to be put in parallel for ~15 seconds in the event the start battery is flattened.

K.

I still have a switch so that I can use the house batteries to start the engine if the start battery dies or use the start battery to run the house if needed.
Only used it once.

Thanks, Lazzz. I guess if you have to use it because the engine start battery is flat then the voltage difference between LiFePO4 and lead-acid isn't the biggest problem. I had thought about just carrying a set of jumper leads should the need ever arise.

K.

I carried one of those small lithium jump start batteries for the lead acid starter battery when I had a mixed system. With the next boat I went for a DCS Lithium system for both starter and house power.

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Bushdog said..
I carried one of those small lithium jump start batteries for the lead acid starter battery when I had a mixed system. With the next boat I went for a DCS Lithium system for both starter and house power.

Thanks, Bushdog. DCS look good.

K.

By the way the temperature monitor/alarm arrived and it is excellent (with the probe tested above my toaster).
It can communicate with a phone app for a remote alarm and temp history but although the phone app seems to work fine I only plan to use the alarm built into the unit which is reasonably loud.
It is USB powered but will run at least 18 hours on the backup battery (specs only claim 5) although I wasn't using the phone app at the time.

$26 but to get advance warning of any issue with my lithium battery while I sleep - priceless. Smoke alarm right above the battery box too btw but that might be a bit late.
The source I bought from on Temu is temporarily out of stock but here is another.

www.banggood.com/Tuya-WiFi-Temperature-Humidity-Sensor-With-LCD-Display-Smart-Life-Remote-Monitor-Indoor-Thermometer-Hygrometer-Via-Google-Alexa-p-1981057.html

To round the conversation up, I did indeed get a flooded century N70t. I concluded that quality old tec was a better investment than mediocre tec & $ I would have liked to go with some of the top end AGM units but you pay for what you get. The AWB siphoned way to many boat dollars recently so the least I could do was stretch the budget to get Aussie made, the century c1275 would have suited me better but ..... I really think or at least hope there's a battery break through just around the corner