# Battery for Garmin Echo 300c



## Agent009 (Jan 3, 2012)

Hi,

Have got a Barracuda SOT on order and obviously it's a light kayak. Because the weight is one of the major selling factors, I want to keep it as light as possible.

So for my sounder, I'm just working out what to use as a battery. I've read various threads on various sizes of SLA's and other threads on using 10x Double A batteries.

I like the double A battery idea as it would be very light. Alternatively, I'm looking at getting a smaller SLA battery (1.3ah or 4.2ah). Really, if I get 4 or 5 hours I'll be happy as very rarely will I be on the water for longer than this.

I have a garmin echo 300c and was just looking at the manul (which can be found below):

http://www.gpscity.ca/pdfs/manuals/ECHO ... MANUAL.pdf

It states on Page 18 of the Appendix that the rated current is 1A. I'm very surprised as this is such a compact unit. In most other thread people were talking about their sounder and the battery drain was usually under 500ma.

So based on this specific sounder, what would people recommend? Would a 4.2ah get me sufficient time on the water? Or maybe I should just go down the path of 10 rechargeable double a batteries.

Cheers


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## Stevie (Jan 16, 2011)

Hi there

As I mentioned in PM a 4.2 AH runs the Echo 300c fine on evey outing so far, up to 5 hours, havent pushed it further. No need for the bigger 7aH one I reckon.

I just velco'ed the battery in front hatch at the moment and it hasnt popped off. I dont open the hatch on water so no issue getting wet but I think I need a better solution for surf and bumpy rides.

Ill get some pics when I get act together of hole drilled into hatch

Steve


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## theGT58 (Nov 1, 2011)

I have the same sounder and went through the same decision, though as my yak is already pretty heavy, being super lightweight didn't matter as much to me. I think you are right that these sounders use more, the only way to know is to whack it on a meter i guess. There is no way they draw 1amp constantly though, maybe in spikes. This sounder is super visible at any rate it is easily readable with the brightness turned down if you want to save juice.

I even considered a Li-ion battery as the cost is basically the same but in the end it was just easier to go the SLA route. Some people seem to think they explode all the time too lol. There was a recent topic about them, some people do use li-ion.

I even considered going at high as 20AH as I intend to run other stuff off it on the yak, and maybe a LED camp light occasionally off the water.

I ended up with a 7.2ah sla. 20ah is just way too chunky. The 7.2ah does the job fine but I will freely admit, while it isn't like a gold bar in the hull or impeding paddling really, i do feel the extra weight as I dont take loads of gear out with me on the yak.

I went for a 7.2 ah for the reasons above, and as often I am away from civilisation and power points a few days and will be camping in a few spots i go to. I therefore want to be sure I have enough juice to run it for two days solid fishing straight (8-12 hours basically) and not kill the battery by decharging it too much. I have run it for 12 hours easily and not had any decline in power and it charges within 2 hrs on returning home.

I agree that is you only want to use it for one 4-5hr session a 4.2 ah will suffice.


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## Agent009 (Jan 3, 2012)

Thanks, that was really handy. With 8 x AA batteries, this would be 2500mah (so 2.5AH)...pretty sure thats correct? So I'm guessing that will only charge this particular FF somewhere between 2 and 3 hours (approximately)?

Hmm not sure which route to go down, 8 x AA or 4.2AH...


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## toddooo (Apr 2, 2012)

Im running 8 aa's and get a few hours out of it. 
I think if your saving on wait thats the best way to go.


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## Stevie (Jan 16, 2011)

If your going a 1.3, 4.2 or 7, all the same connection, so it not too big a deal I think to swap around. Trial and error is what kayak fishing is all about! The 4.2 is enough really but Id be keen to know if the little 1.3AH one lasted a few hours?, as I tend to only turn mine on when I need it (in target area).


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## Agent009 (Jan 3, 2012)

Stevie, I think I'm starting to understand the batteries now lol. 8 x AA batteries is 2.5AH and would probably last somewhere around the 3 hour mark (on the echo 300c). So a 1.3 SLA would probably last 1.5hrs. I'm going to go down the double A path now as I REALLY want to keep the barracuda lightweight (considering this is one of its major selling points). I'm happy with 3 hours and will be getting rechargeables.

With the charger, can you get one that can recharge 8 double a batteries at once? I can only find 4 cell chargers...


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## bildad (Jun 20, 2011)

:twisted:


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## Agent009 (Jan 3, 2012)

Curse you bildad! Just another thing for me to consider now haha.


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## bildad (Jun 20, 2011)

:twisted:


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## ant (Aug 28, 2008)

Agent I have the same garmin and use a 2.Ah which lasts me around 5-6 hours of use.
Cheers
Ant


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## spongy (Nov 13, 2008)

I have a 300c as well and have been using a very similar battery that bildad uses, but mine is smaller, about the same size as a small pack of ciggies. It says it's 5000mah but from the physical size, I doubt its anything close to that claim. I estimate it to be about 2500mah. Regardless, I easily get 6 hours run time, and voltage drops down to about 11.5v by the time I'm off the water. 
Highly recommend these lithium ion batteries. Just make sure you take care of them, don't drop them and don't get them wet. They have a potential to "explode" when charging, if the battery has been mistreated. The charger that came with the battery failed after a month, however I am using another 12v power pack and works just fine. The battery pack has protection circuitry, so any 12v power pack will do.


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## spongy (Nov 13, 2008)

Another option is to buy some 18650 lithium ion cells and put 4 in series to give you a 15volt battery pack. The 300c will run fine on 15volts. Grab a 4 cell battery holder and a charger, all up should cost you about $25 from Eprey. Only issue with this setup is you need to monitor the voltage as you use it and ensure it doesn't drop below a threshold voltage. Can't remember exactly what it is but something like 11 volts.


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## bildad (Jun 20, 2011)

spongy said:


> Another option is to buy some 18650 lithium ion cells and put 4 in series to give you a 15volt battery pack. The 300c will run fine on 15volts. Grab a 4 cell battery holder and a charger, all up should cost you about $25 from Eprey. Only issue with this setup is you need to monitor the voltage as you use it and ensure it doesn't drop below a threshold voltage. Can't remember exactly what it is but something like 11 volts.


I mentioned these exact batteries in above post, the 18650s I use have circuit protection fully charged 16.8 volts you can run 20 volts in the Garmin 300C they lose there amperage at around 13.5 to 14 volts.


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## MrX (Feb 7, 2008)

> "I even considered a Li-ion battery as the cost is basically the same but in the end it was just easier to go the SLA route. Some people seem to think they explode all the time too lol. There was a recent topic about them, some people do use li-ion."


http://www.akff.net/forum/viewtopic.php?f=12&t=52020

Tried a few battery set ups:
- series of AA's (too much hassle to charge, and limited time);
- SLA's of different sizes (big and heavy, designed for high-current devices - like starting motorbikes and outboards).

Li-ion batteries are designed to power low draw electrical devices - laptops, CCTV cameras, sharkshields, etc. Light, small, easy to use - perfect power source for yak sounders.

No shortage of options:

http://www.ebay.com.au/itm/1x-12V-4...ronics_Batteries_Chargers&hash=item1c21f7169b

http://www.ebay.com.au/itm/Super-Re...ronics_Batteries_Chargers&hash=item19c36eac37

The expoldo concerns are a bit of mischief-making. The currently available li-ion batteries, and dedicated chargers, have circuitry to protect from over recharge and over discharge. I rate them safer to carry on my yak than an unprotected SLA (which could theoretically heat up your wires enough to melt your yak if they short).

Like any battery, you need to look after it, and keep it dry. If you wet a li-ion, you will kill it (but it's not going blow up).


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## Agent009 (Jan 3, 2012)

I'm definitely going with double A batteries.

But I'll use 10 as the rechargeables are only 1.2 Volt. I also have a charger which charges all ten at once...so in my opinion this is just as easy as chargin a SLA.

Expect to get 5-6 hours out of this which is ample for myself. Plus I'm not adding any weight to the yak which is the biggest coupe as this is one of the major reasons why I chose the Barracuda.

Also going to use Sanyo XX batteries as I believe these are the best on the market at this point in time. So may even got 6+ hours


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## spongy (Nov 13, 2008)

Sanyo XX AA batteries are nice batteries, but its not the most cost effective solution. 10 AA cells will set you back around $40-50, not including a charger.


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## Agent009 (Jan 3, 2012)

Hey Spongy,

Yeah I know its not the most cost effective...but I figured I'm happy to spend $50 more if I can keep a heavy SLA off my yak. And really, what's $50 these days anyway! 

Cheers
Agent


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## spongy (Nov 13, 2008)

No worries Agent,
Each to their own.
I would have preferred going Li-Ion rather than Ni-Mh, but either of these is a much better solution than SLA.


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