trophywife
Crew Member
i want to understand the pros and cons of changing my boats over to lithium. smaller? more cranking amps? i am no sparky.
Lithium Batteries? School Me , marine/boat applications!
- Thread starter trophywife
- Start date
Max123
Well-Known Member
For starting battery, lithium isn't recommended. I think there are only one or two different manufacturers that have a factory lithium starting battery.
Here's my understanding (feel free to correct me): all Lithium batteries include a battery management system (BMS) that controls charging and protects the battery - because an unhappy lithium battery can cause a runaway reaction leading to a serious fire. When you start a large engine, a lot of things happen very quickly - large amount of current out, and then a quick change as the alternator takes over and begins to charge. This can cause a lithium battery BMS to trip to protect the battery. If the battery trips - the alternator on your engine has nowhere to dump the excess current - poof, you just fried the electrical system on your outboard.
Lead acid batteries don't have a BMS - they use the basic chemistry of their construction to act as a big shock absorber on your electrical system, If they get excess charge for a few seconds - water turns to a bit of hydrogen - no harm done (hopefully).
For an engine battery - flooded lead acid, or AGM. For house load - lithium can store vastly more energy, lasts longer, can be run down further with no damage, etc.
Here's my understanding (feel free to correct me): all Lithium batteries include a battery management system (BMS) that controls charging and protects the battery - because an unhappy lithium battery can cause a runaway reaction leading to a serious fire. When you start a large engine, a lot of things happen very quickly - large amount of current out, and then a quick change as the alternator takes over and begins to charge. This can cause a lithium battery BMS to trip to protect the battery. If the battery trips - the alternator on your engine has nowhere to dump the excess current - poof, you just fried the electrical system on your outboard.
Lead acid batteries don't have a BMS - they use the basic chemistry of their construction to act as a big shock absorber on your electrical system, If they get excess charge for a few seconds - water turns to a bit of hydrogen - no harm done (hopefully).
For an engine battery - flooded lead acid, or AGM. For house load - lithium can store vastly more energy, lasts longer, can be run down further with no damage, etc.
Max123
Well-Known Member
I think these are the guys that make one of the few (possibly only) battery that Mercury Marine certified for use with their engines
www.relionbattery.com
Lithium Marine Battery Dual Purpose | RELiON
The RB100-HP is a dual purpose deep cycle battery that can handle both starting and cycling in marine applications.
www.relionbattery.com
kaelc
Crew Member
First, talk to a marine electrician and check out the youtube marine electrical series by jeff? in Vancouver? Don't listen to internet cowboys like me especially when it comes to electrical!
Dakota and a few others make Starting Lithium batteries but do your research, one on ebay by another brand did not even have a cold cranking amp much less marine cranking amps. The dakota's and others lithium lipe04 starting batteries I have seen are very expensive.
House batteries are cheaper, but you'll require a DC-to-DC charger to use your alternator to charge them, or solar array. Your existing shorepower charger may not charge them fully. New Victron and noco charge them other ones...? Look at the owners manual or sales page for your onboard charger.
Try to get one with low temp charging protection as well.
I think I can get discounts for Eco-Worthy products, which are the most affordable ones, but based on my research, I'd look at Litime for marine house batteries.
Dakota and a few others make Starting Lithium batteries but do your research, one on ebay by another brand did not even have a cold cranking amp much less marine cranking amps. The dakota's and others lithium lipe04 starting batteries I have seen are very expensive.
House batteries are cheaper, but you'll require a DC-to-DC charger to use your alternator to charge them, or solar array. Your existing shorepower charger may not charge them fully. New Victron and noco charge them other ones...? Look at the owners manual or sales page for your onboard charger.
Try to get one with low temp charging protection as well.
I think I can get discounts for Eco-Worthy products, which are the most affordable ones, but based on my research, I'd look at Litime for marine house batteries.
kaelc
Crew Member
Dig deep into the warranties. Not sure how many of these companies will even be in business in 5 years but this one claims 11 years but it is only if "properly" used https://dakotalithium.com/product/d...r-starter-deep-cycle-lifepo4-battery-1000cca/
kaelc
Crew Member
The ability to be drawn down much further than traditional batteries without damaging, and the high voltage, even when depleted over 60%, combined with much lower weight are the greatest advantages. I replaced two group 27 batters at approximately 40lbs each with one 100ah lithium lifepo4 at under 25lbs
CBsqrd
Well-Known Member
I installed a Lithium house two years ago and can provide my thoughts. My setup is twin outboards (300hp), each with their own start battery and a separate house battery.
Mercury is the only manufacturer (as far as I know) that approves the use of Lithium for starter batteries, specifically their own brand RELiOn. Other than weight, the advantages for lithium vs AGM / lead acid as a starter are limited as the needs for a starting battery are pretty simple - deliver the current for a short period when needed. Since they are connected to the engine, they are the first to be charged so generally are topped up and ready to use. Once you meet the engine manufacturers recommended specs, there isn't really an advantage to going bigger.
The big advantage for Lithium is as a house battery as you get a number of benefits besides weight, including:
- more usable capacity. A Lithium battery can be drawn down further than a lead acid without damaging it. Generally lead acid's shouldn't be drawn down more than 50% of their stated capacity otherwise they will be damaged. Lithium batteries can go to 20% or lower without issue. This allows you to get more for a given amp-hour rated battery, or use an even smaller battery than you'd be replacing.
- "higher quality voltage". related to above, on a lead acid, as you draw down the battery you will see your voltage drop. Lithium batteries will maintain the same voltage right down until the shut off.
- less self discharge. Lead acid batteries can lose up to 30% of their charge in a month. Lithium will be 2% - 3% per month.
- up to 5x faster charging.
- Longer life, 5 - 10 years for a Lithium battery which can handle many more charge cycles.
You will have to set up a DC-DC charging system, a DVSR system that most boats have won't work. It's pretty straightforward, see below of the picture of my setup. I also added a battery monitor and the Victron app also provides info the DC-DC chargers. Note that the BMS is there to protect the battery, it doesn't manage charging.
Happy to answer any questions. I've been super happy since I switched over. I went with a Battleborn battery. Apologies for the duplicate info to what @kaelc posted while I was typing this.
Mercury is the only manufacturer (as far as I know) that approves the use of Lithium for starter batteries, specifically their own brand RELiOn. Other than weight, the advantages for lithium vs AGM / lead acid as a starter are limited as the needs for a starting battery are pretty simple - deliver the current for a short period when needed. Since they are connected to the engine, they are the first to be charged so generally are topped up and ready to use. Once you meet the engine manufacturers recommended specs, there isn't really an advantage to going bigger.
The big advantage for Lithium is as a house battery as you get a number of benefits besides weight, including:
- more usable capacity. A Lithium battery can be drawn down further than a lead acid without damaging it. Generally lead acid's shouldn't be drawn down more than 50% of their stated capacity otherwise they will be damaged. Lithium batteries can go to 20% or lower without issue. This allows you to get more for a given amp-hour rated battery, or use an even smaller battery than you'd be replacing.
- "higher quality voltage". related to above, on a lead acid, as you draw down the battery you will see your voltage drop. Lithium batteries will maintain the same voltage right down until the shut off.
- less self discharge. Lead acid batteries can lose up to 30% of their charge in a month. Lithium will be 2% - 3% per month.
- up to 5x faster charging.
- Longer life, 5 - 10 years for a Lithium battery which can handle many more charge cycles.
You will have to set up a DC-DC charging system, a DVSR system that most boats have won't work. It's pretty straightforward, see below of the picture of my setup. I also added a battery monitor and the Victron app also provides info the DC-DC chargers. Note that the BMS is there to protect the battery, it doesn't manage charging.
Happy to answer any questions. I've been super happy since I switched over. I went with a Battleborn battery. Apologies for the duplicate info to what @kaelc posted while I was typing this.
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trophywife
Crew Member
the juice doesnt seem worth the squeeze. thank you for the easy information crew.
Corey_lax
Crew Member
I've also given up on Canadian Tire batteries recently. I only buy them if I need one at like 8:00pm and it's the only store open.
But the warranty! New one every year.
Corey_lax
Crew Member
There’s no time to deal with warranty issues every year. I’d rather buy quality
I remove them for winter so new big deal.
Fisheries Supply has some excellent online product education
Marine Batteries 101
www.fisheriessupply.com
Marine Batteries 101
Choosing the Right Marine Battery | Fisheries Supply
Read the Fisheries Supply guide to help you choose the best marine battery for your bank of batteries. We review flooded, AGM, gel and lithium ion batteries.
www.fisheriessupply.com
Salmon Seeker
Crew Member
Im thinking of getting one just to run my sounder. would 30 amp hours be enough to run the sounder for a day on the water? humminbird 788
sounder is currently hooked up straight to the main battery but every time i crank the engine it freezes the sounder then i have to disconnect/reconnect to the battery to get the sounder running again. I think my main battery is nearing its end of life but is still working for cranking purposes.
sounder is currently hooked up straight to the main battery but every time i crank the engine it freezes the sounder then i have to disconnect/reconnect to the battery to get the sounder running again. I think my main battery is nearing its end of life but is still working for cranking purposes.
kaelc
Crew Member
Likely but as you add draw, with more electronics or electric reels, or do two days of fishing without hooking to a charger, it will quickly become too small. I’d go for 100ah mini with a solar panel to keep charged if you aren’t going to add a blue seas add a battery kit and a dc to dc charger. I’d get an agm from Costco first and see if that fixes the problem.
Alex_c
Well-Known Member
Checked the specs of your unit, and it draws 650 mA, or 0.65 A. With a 30 ah battery you could run it for 36 hours and discharge the battery 80%
Max123
Well-Known Member
I suspect that when you start, you are getting too much voltage drop and its cutting out the sounder. Start by checking your electrical connections for any buildup, but a battery would probably cure the issue best - make sure it is rated for enough CCA. I bought a Costco Energizer AGM - great battery, great price, great costco warranty.
In the meantime, if that battery is on borrowed time I'd start carrying a jump pack, just in case.
In the meantime, if that battery is on borrowed time I'd start carrying a jump pack, just in case.
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