Battery for Garmin Echomap 7sv

[Chaos10691]

Just ordered this unit for my kayak, but my current battery is old. I’m looking to buy a new battery that’ll keep it running for the 4-6 hours I’m on the water. I believe the draw is 1.25 a/hr. Say a battery is a 12V 10ah battery does that mean it’ll maintain 12 volts for 8 hours with this unit? Or will it start to dip below as it’s being drained? Either way any recommendations for decent batteries that won’t break the bank is much appreciated.

[WRB]

I would consider a 30 AH AGM or 30 AH lithium deep cycle like VMax Tank on sale with battery box.

Tom

[MN Fisher]

If it's a LiFePo battery - ya, you can run it for that 4-6 hours without an issue. If it's a SLA or AGM...need to up the capacity to a 20.

 

 

[Chaos10691]

46 minutes ago, MN Fisher said:

If it's a LiFePo battery - ya, you can run it for that 4-6 hours without an issue. If it's a SLA or AGM...need to up the capacity to a 20.

 

 

What’s a life pro? And what is SLA and AGM? And why do I need to up the capacity on those?

[MN Fisher]

LiFePO is Lithium-Iron-Phosphate - the latest generation of rechargeable Lithium batteries.

SLA is Sealed Lead-Acid - like you use in your car/truck/SUV...known as 'maintenance free'.

AGM is Absorbent Glass Mat - an improvement on SLA, but still uses acid in water.

 

LiFePo batteries can be drained to 10% max charge without issue

SLA and AGM batteries, you're restricted to 50% charge before you start damaging them.

 

So to get 6 hours of use at 1.25amps - you need 7.5AH usable. LiFePo, an 8ah battery would suffice, but better to have a little more buffer. SLA or AGM, you need a minimum of 15ah...so the 20ah battery gives you that margin.

[Chaos10691]

34 minutes ago, MN Fisher said:

LiFePO is Lithium-Iron-Phosphate - the latest generation of rechargeable Lithium batteries.

SLA is Sealed Lead-Acid - like you use in your car/truck/SUV...known as 'maintenance free'.

AGM is Absorbent Glass Mat - an improvement on SLA, but still uses acid in water.

 

LiFePo batteries can be drained to 10% max charge without issue

SLA and AGM batteries, you're restricted to 50% charge before you start damaging them.

 

So to get 6 hours of use at 1.25amps - you need 7.5AH usable. LiFePo, an 8ah battery would suffice, but better to have a little more buffer. SLA or AGM, you need a minimum of 15ah...so the 20ah battery gives you that margin.

Ok gotcha thank you I’ll look into those lifepo batteries. 

[WRB]

VMax Tank makes very good high quality batteries at decent price points.

AGM you can mout upside down or in any position and change using nearly any charger that meets the

requirements.

10 AH is V10 to 30 AH V30-800 Weight 35 lbs, V20-600 is 13 lbs.

Lithium batteries are 1/3 the weight and require special charging that you need to factor into cost.

30 AH LEPUI1230 is a lifeP04 with charger. Weight 8 lbs.

Tom

[schplurg]

I have 2 x 11 ah AGMs in my yak for fish finder, plus lights, cameras and recharging of phones or whatever. They just were the best fit for my DIY "Hot Box" power box. I use it camping to power stuff too.

 

Go ahead and laugh at my electronics "skillz". There's a piece of wood in the bottom cut out to hold the batteries in place.

 

 

 

[Chaos10691]

4 hours ago, schplurg said:

I have 2 x 11 ah AGMs in my yak for fish finder, plus lights, cameras and recharging of phones or whatever. They just were the best fit for my DIY "Hot Box" power box. I use it camping to power stuff too.

 

Go ahead and laugh at my electronics "skillz". There's a piece of wood in the bottom cut out to hold the batteries in place.

 

 

 

I like that setup. When you charge it do you just connect to the banana plugs on top?

[schplurg]

8 hours ago, Chaos10691 said:

I like that setup. When you charge it do you just connect to the banana plugs on top?

Yep. Flip the switch to activate the plugs and it works like a champ. I bought all the parts on Amazon. The box goes in the milk crate.

 

One problem I have is that if I toss stuff in the crate it can turn the switches off. I'm going to build a combo power - tackle box with built in switches and ports, maybe out of ABS. It's a project I'd like to do anyways.

[Seafury]

All you probably need is a 10AH Lifepo4 battery.

 

I am using this one from Amazon.

It was $50 but no charger. 

I run a Garmin Echomap 93sv with GT54 UHD Transducer. 

Amazon.com: 12V 10Ah Lithium LiFePO4 Deep Cycle Battery, 2000+ Cycles Rechargeable Battery, Maintenance-Free Battery for Solar/Wind Power, Lighting, Power Wheels, Fish Finder and More, Built-in BMS : Health & Household

 

I fly RC airplanes so I already have badass digital Lithium battery chargers that can charge pretty much any type of battery.

 

I also had my wife buy me this 18AH battery for Christmas for those really long day trips.

For $150 it includes a no brainer Lifepo4 charger.

12v 18ah Lithium Battery (LiFePO4) | Amped Outdoors

 

This website is nice, they also have a cool chart in the middle of this listing that shows the popular fish finder brands/models and what size/type of battery will give you what run time.

Made the decision super easy.

 

By the way, if you mount this on the same side, and use the Yakattack switchblade mount for the transducer like I did, your Yak will list to that side lol.

I am debating putting the screen on one side and the Transducer on the other and running the lines across behind me or something to make it level again.

Battery is always centered in the kayak.

 

 

 

 

 

[Choporoz]

I use 10ah SLA'S from Amazon for my 73SV.  I run them pretty hard and only get a year out of them, generally.  I will probably go with LiPO next time....would have by now, but I have five chargers already and was putting it off to keep from getting a sixth

[Way2slow]

When doing the math on battery capacity to figure run time.  There are two variables you have to take into consideration.  A 10Ah battery is rated at,' from the time it's fully charged until is reaches the point of being fully discharged.  That's usually in the lower 11 volt range.  Your electronics are not going to stay on until reaches that fully discharged level.  Many won't even stay on until is at 25 to 35 percent charged.  So, you have to figure in how long it's going to run until it cuts off, not how long is before the battery is fully discharged.

That's where LiPo batteries have a major advantage over lead acid batteries.  They tend to hold a working level voltage until they are almost fully discharged, then they just drop out.   So, in this situation, I personally would only consider a LiPo battery.  You will get more run time that a similar size lead acid and they are a whole lot lighter.  

[Chaos10691]

4 hours ago, Way2slow said:

When doing the math on battery capacity to figure run time.  There are two variables you have to take into consideration.  A 10Ah battery is rated at,' from the time it's fully charged until is reaches the point of being fully discharged.  That's usually in the lower 11 volt range.  Your electronics are not going to stay on until reaches that fully discharged level.  Many won't even stay on until is at 25 to 35 percent charged.  So, you have to figure in how long it's going to run until it cuts off, not how long is before the battery is fully discharged.

That's where LiPo batteries have a major advantage over lead acid batteries.  They tend to hold a working level voltage until they are almost fully discharged, then they just drop out.   So, in this situation, I personally would only consider a LiPo battery.  You will get more run time that a similar size lead acid and they are a whole lot lighter.  

I’m looking at one on Amazon that’s a 20ah but I’m not sure I need that much. It’s only 69.99 but I’ll probably have to buy a charger as well. Any recommendations on a charger

[MN Fisher]

11 minutes ago, Chaos10691 said:

I’m looking at one on Amazon that’s a 20ah but I’m not sure I need that much. It’s only 69.99 but I’ll probably have to buy a charger as well. Any recommendations on a charger

This one

https://www.amazon.com/NOCO-GENIUS2-Fully-Automatic-Temperature-Compensation/dp/B07W6B987F/ref=sr_1_5?crid=6C56SVWNML9U&keywords=noco+genius&qid=1639445354&s=automotive&sprefix=noco+%2Cautomotive%2C296&sr=1-5

[Chaos10691]

19 minutes ago, MN Fisher said:

This one

https://www.amazon.com/NOCO-GENIUS2-Fully-Automatic-Temperature-Compensation/dp/B07W6B987F/ref=sr_1_5?crid=6C56SVWNML9U&keywords=noco+genius&qid=1639445354&s=automotive&sprefix=noco+%2Cautomotive%2C296&sr=1-5

So I had read that the charging voltage for LifePo4 is something like 14.6V. Would a 12V charger be able to charge it to full?

[Seafury]

22 minutes ago, MN Fisher said:

This one

https://www.amazon.com/NOCO-GENIUS2-Fully-Automatic-Temperature-Compensation/dp/B07W6B987F/ref=sr_1_5?crid=6C56SVWNML9U&keywords=noco+genius&qid=1639445354&s=automotive&sprefix=noco+%2Cautomotive%2C296&sr=1-5

That's a great charger if you want to run a weak heavy traditional battery.

You're better off with a Lifepo4 charger.

 

Lithium is way cheaper now, your much better off with a lighter battery with more usable capacity.

Weight is the enemy of everything, including boats.

 

Amazon is full of options, just search for whatever AH rating your looking for.

Amazon.com : 10ah lifepo4 battery

 

Then lifepo4 chargers.

Amazon.com : lifepo4 battery charger

 

The 10AH Lifepo4 I got will run the 73sv for around 8hours based on this chart.

Garmin® | Amped Outdoors

 

I rarely even consider traditional SLA or even AGM batteries for most things anymore.

 

 

 

3 minutes ago, Chaos10691 said:

So I had read that the charging voltage for LifePo4 is something like 14.6V. Would a 12V charger be able to charge it to full?

No, not a good idea.

 

You need a charger specifically designed for lipo batteries, specifically Lifepo4, which is 4 cell 14.6v fully charged.

 

Regular chargers can work, but it's risky and they won't charge the Lifepo4 to full charge.

 

Why risk burning down your house?

Just get a decent Lifepo4 and a Lifepo4 charger, they are not expensive unless money is super tight.

[Chaos10691]

5 minutes ago, Seafury said:

That's a great charger if you want to run a weak heavy traditional battery.

You're better off with a Lifepo4 charger.

 

Lithium is way cheaper now, your much better off with a lighter battery with more usable capacity.

Weight is the enemy of everything, including boats.

 

Amazon is full of options, just search for whatever AH rating your looking for.

Amazon.com : 10ah lifepo4 battery

 

Then lifepo4 chargers.

Amazon.com : lifepo4 battery charger

 

The 10AH Lifepo4 I got will run the 73sv for around 8hours based on this chart.

Garmin® | Amped Outdoors

 

I rarely even consider traditional SLA or even AGM batteries for most things anymore.

 

 

 

No, not a good idea.

 

You need a charger specifically designed for lipo batteries, specifically Lifepo4, which is 4 cell 14.6v fully charged.

 

Regular chargers can work, but it's risky and they won't charge the Lifepo4 to full charge.

 

Why risk burning down your house?

Just get a decent Lifepo4 and a Lifepo4 charger, they are not expensive unless money is super tight.

That’s what I thought and uhhh what’s the real risk of burning down my house with this stuff?

[MN Fisher]

15 minutes ago, Seafury said:

That's a great charger if you want to run a weak heavy traditional battery.

You're better off with a Lifepo4 charger.

The NOCO Genius line IS rated for LiFePo batteries with a BMS system.

[Seafury]

8 minutes ago, Chaos10691 said:

That’s what I thought and uhhh what’s the real risk of burning down my house with this stuff?

It varies tbh.

 

I follow fairly safe battery practices from flying RC planes, but even I don't do everything you are supposed to.

 

Never had an issue yet, but cheap batteries can be dangerous sometimes.

Most batteries like everything else are made in a handful of the same factories.

 

The main points are NEVER leave batteries charging when not home, and don't leave charging batteries unattended for long periods of time.

I am either working in the room while charging, or coming into that room ever 20-30mins to check on things.

 

The other thing is you are supposed to charge the battery while it's in a fire safe bag, which is a huge pita and I have rarely ever done.

 

Lifepo4 is somewhat safer than the li ion batteries in my model airplanes though.

Mine are smaller and more volatile and have fast discharge and charge rates.

 

Modern lithium's are a little more dangerous then nicads and SLA's and AGM's, because they will burst into flames if something goes wrong.

 

 

[Chaos10691]

1 hour ago, Seafury said:

It varies tbh.

 

I follow fairly safe battery practices from flying RC planes, but even I don't do everything you are supposed to.

 

Never had an issue yet, but cheap batteries can be dangerous sometimes.

Most batteries like everything else are made in a handful of the same factories.

 

The main points are NEVER leave batteries charging when not home, and don't leave charging batteries unattended for long periods of time.

I am either working in the room while charging, or coming into that room ever 20-30mins to check on things.

 

The other thing is you are supposed to charge the battery while it's in a fire safe bag, which is a huge pita and I have rarely ever done.

 

Lifepo4 is somewhat safer than the li ion batteries in my model airplanes though.

Mine are smaller and more volatile and have fast discharge and charge rates.

 

Modern lithium's are a little more dangerous then nicads and SLA's and AGM's, because they will burst into flames if something goes wrong.

 

 

So are modern lithiums and lifepo4 not the same thing? Is the lifepo4 safer than SLA?

[MN Fisher]

There is a difference between Lithium-Ion and LiFePo.

 

LiFePo batteries are more stable - they're not subject to the temperature instability, they stay cooler in high-heat conditions, and they're not subject to exploding due to rapid charging-discharging-short circuits. They're also non-toxic, so disposal is much easier

 

Lithium-Ion batteries have a higher charge-weight ratio...more energy can be stored per kilogram of weight, so they're usually lighter for the same AH rating...which is why they're still used in small devices like phones, tablets, etc.

 

More about the differences at https://blog.epectec.com/lithium-iron-phosphate-vs-lithium-ion-differences-and-advantages

[Seafury]

10 hours ago, MN Fisher said:

The NOCO Genius line IS rated for LiFePo batteries with a BMS system.

Yes and no.

 

I was reading those on Amazon.

 

The cheaper models do not mention lifepo4, just SLA AGM and Gel.

The $100 models do mention lifepo4.

 

At $100, just get a cheaper lifepo4 charger, unless you need a charger for other batteries also.

 

Hell from $100-200 you can get a high-end RC battery charger these days that can charge anything lithium in record time with full digital control and battery stats on display.

 

Gotta do your homework to find the right fit at the right price

9 hours ago, Chaos10691 said:

So are modern lithiums and lifepo4 not the same thing? Is the lifepo4 safer than SLA?

Yes, "modern lithium's" means all the modern lithium type batteries.

 

They say lifepo4 are safer than the li ions I use in my RC models, but idk about that.

We use some of those lifepo4 batteries now in some RC models.

 

I guess they are slightly safer, but lithium's in general are more dangerous than SLA AGM GEL.

 

At the end of the day, ALL batteries are dangerous if not properly cared for and handled.

We as a society take these for granted all the time.

 

Just follow the safety rec's and use decent gear and you will be fine.

 

They are TOTALLY worth the better power, and much lighter weight.

[Chaos10691]

46 minutes ago, Seafury said:

Yes and no.

 

I was reading those on Amazon.

 

The cheaper models do not mention lifepo4, just SLA AGM and Gel.

The $100 models do mention lifepo4.

 

At $100, just get a cheaper lifepo4 charger, unless you need a charger for other batteries also.

 

Hell from $100-200 you can get a high-end RC battery charger these days that can charge anything lithium in record time with full digital control and battery stats on display.

 

Gotta do your homework to find the right fit at the right price

Yes, "modern lithium's" means all the modern lithium type batteries.

 

They say lifepo4 are safer than the li ions I use in my RC models, but idk about that.

We use some of those lifepo4 batteries now in some RC models.

 

I guess they are slightly safer, but lithium's in general are more dangerous than SLA AGM GEL.

 

At the end of the day, ALL batteries are dangerous if not properly cared for and handled.

We as a society take these for granted all the time.

 

Just follow the safety rec's and use decent gear and you will be fine.

 

They are TOTALLY worth the better power, and much lighter weight.

So what charger would you recommend? I was looking at the Dakota Lithium site and they have chargers for 29.99 that are 3ah and output 14.6V would that be ok?

[Seafury]

9 hours ago, Chaos10691 said:

So what charger would you recommend? I was looking at the Dakota Lithium site and they have chargers for 29.99 that are 3ah and output 14.6V would that be ok?

Think I read we want 2AH charger for lifepo4.

However, I am unsure if the charge rate is related to the battery capacity ie: 10AH, 18AH etc.

With my RC Li ion batteries, the max charge rate depends on the capacity and rating.

 

Fast charging any type of lithium shortens it's life though.

 

I am still new to these specific batteries myself, although we do use some in RC airplanes nowadays.

 

Anyone know for sure the proper charge rate for lifepo4 batteries?