Electric outboard motor batteries

Cap'n Fishy

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I'm trying to get my head round replacing my Halfords 110 AH lead-acid leisure battery with a few vapers. :D:D:D
 

scobo

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Nearly done. Just got to finish the rest of the series and parallel connections and connect the charge/discharge leads.

IMG_20191015_163820.jpg
 

franticfisherman

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Looks good Scott, keep us up to date on its performance!
As well as making sure my lipos are stored at about half-charge, I also disconnect each one from the wiring harness when they are not in use. That way a duff cell will only affect the other 2 around it and not the whole set-up.
My system is still working well with no drop off in capacity or performance although I did have to scrap the 60amp circuit breaker because it kept cutting off the power. Don't know if it was faulty or not but I'm doing without it now.
I had a bit of a scare during the heatwave in July. The batteries got extremely hot because they were in the sun inside what is effectively a little greenhouse. They expanded a bit and I thought they were fried but they were OK thankfully. Now on a sunny day I cover them with something to keep the sun off!
Cheers
frantic
 

scobo

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As well as making sure my lipos are stored at about half-charge, I also disconnect each one from the wiring harness when they are not in use. That way a duff cell will only affect the other 2 around it and not the whole set-up.

Yeah I kept mine at 50% too when not in use for a while and was always pretty careful with the connections to the parallel board ....... apart from one time when I connected the balance lead from one of the packs to the wrong connector on the board. :eek:mg:
Won't have that problem with the new setup as there's only one set of charge/discharge leads and one balance lead. The 18650 cells are all connected in series/parallel as one pack.
Should get it finished at the weekend and can start testing it for capacity, etc.
 
D

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That's a great piece of work Scott. :thumbs: Credit to you.

Luckily, I don't need anything so light and compact, as I strap my Halfords 115Ah Leisure battery under the forward seat of my boat at the start of the season in February and don't remove it until after the end of September. Then I keep it on maintenance charge until it's next installed on the boat.

It's charged from my outboard engine, which has a nominal 6A output and I have everything cabled through a junction box as a bus system, and a cable runs the length of the boat from the junction box to the battery, and there's a waterproof connector on a flying lead to plug for my electric engine, a cable running to my electric bilge pump with an ON/OFF switch on the junction box and the cable connecting the outboard engine to the junction box.

I only use the electric engine to trim my drifts, instead of using the oars, the battery never runs down throughout the entire season. My Water Snake electric engine has a digital voltage indicator built in, so I'm always able to see both the static battery voltage, and the charging voltage when the boat's underway.

For interest, I'll photograph the set up at some point, but for now I have it all stripped off the boat to enable thorough cleaning and wood treatment. Also, I'll probably modify the junction box to add a USB phone charger outlet.
 

franticfisherman

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Ahoy Scott, was a bit puzzled by your new setup. You say there is only one balance lead, shouldn't there be one for each trio of cells? I'm just thinking of my lipo setup and your old system, each battery needs to have it's cells balanced so the charger/charging plate supplies a lead to each one. If the trios of 1860 cells all need a set of balance wires, that's a heck of a lot of wires you will need!
Cheers
frantic
 

scobo

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Ahoy Scott, was a bit puzzled by your new setup. You say there is only one balance lead, shouldn't there be one for each trio of cells? I'm just thinking of my lipo setup and your old system, each battery needs to have it's cells balanced so the charger/charging plate supplies a lead to each one. If the trios of 1860 cells all need a set of balance wires, that's a heck of a lot of wires you will need!
Cheers
frantic

Hi Phil, it works a bit differently to the lipo setup although you still you have 3 cells making up your 12 volts like you have in a 3S lipo pack. Think of this as one great big lipo pack.
This diagram shows the wiring better than I can explain.

Picture (Device Independent Bitmap) 1.jpg

That's how each row in my pack is set out and connected.
There's 13 batteries connected in parallel in each row and each row makes up one of the 3 cells which are connected in series.
This is it with all series and parallel connections finished, still got to connect the main charge/discharge leads.
The blue & black caps are negative and the red & orange are positive.

IMG_20191107_183546.jpg

The balance lead has 4 wires, the black goes to the negative in the first cell and the other wires each connect to the positive in one of the 3 cells.
Hope this makes sense.
 

franticfisherman

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Thanks for that Scott, I think I get it! I hope it works OK for you. If I ever fry my lipo set up I will go for something like that. It is a lot cheaper and easier to replace any cells if they fail.
PS your kitchen unit handles are the same as mine! Ha ha!
frantic
 

scobo

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Thanks for that Scott, I think I get it! I hope it works OK for you. If I ever fry my lipo set up I will go for something like that. It is a lot cheaper and easier to replace any cells if they fail.
PS your kitchen unit handles are the same as mine! Ha ha!
frantic

Cheers Phil.
Takes a bit of time to put together but no more than a cold Saturday afternoon in the winter. :D
One thing I've learned since testing it is that the capacity isn't quite as stated.
It should be 39ah (3000mah x 13) but the charger is saying about 35ah.
Sure enough, when I googled the Samsung batteries I'm using, the useable capacity is listed as 2700mah per battery instead of 3000mah so 35ah is about right.
Might need to add a few more cells to the pack but we'll see how it goes.
 

scobo

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What do you reckon your total costs are there, Scott?

I spotted this...

Mastervolt MLS Lithium Battery – Glasgow Angling Centre

Hmmm... £675.99 for 30 AH, anyone? :eek:

You should think about going into business for yourself. ;)

Col

The 39 Samsung batteries I used came to about £100. You can get them for about £2.70 each when you buy them in bulk.
The Vruzend kit to connect them all together was about £40 but if you have a spot welder or don't mind a fair bit of soldering, you could get the nickel strips for less than a tenner.
The charging leads are just a couple of quid so you could do it for about £110 or so, all in.

Those GAC batteries are a bit steep, even for an off-the-shelf job.
We just got a pair of Pylontech lithium batteries for the house to store surplus power from the solar panels on the roof.
Each battery is 2.4kwh or 50ah at 48 volts and cost £700 each.
That's about the equivalent of 200ah at 12 volts !
 

bokbok59

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Kalahari desert RSA
I use 110Ah Exide deep cycle solar system batt now for 7 years, when not in use I store it properly and charge often, here is the problem.
Put whatever you have heard or been taught about “Deep Cycle” and “High Cycle” batteries out of your mind. Every lead-acid battery can be deeply discharged. What is important is the number of times each particular battery can be discharged at a chosen depth of discharge (DOD). For example an Excis 100 battery (102Ah) from First National Battery can give 950 cycles (load shedding occurrences) if only 30% of its capacity is removed each cycle, 500 cycles if 50% is removed and only 60 cycles if 80% is removed (based on a 25°C operating temperature and correct charging).
Do not size your system so that you remove 80% of the batteries capacity each cycle and expect 2 years battery life as you will more than likely only get 2-3 months life!
 

robbie

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Hi There,

This just came up on my Facebook page.


Any use?

Best Regards

Robbie
 

scobo

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Hi There,

This just came up on my Facebook page.


Any use?

Best Regards

Robbie
I doubt it very much Robbie.
These type of devices are only designed for providing large amounts of power in short bursts. The 12V socket for powering devices for longer periods is only rated for 10amps, you need about 40amps for a leccy outboard motor.
Even if it could provide enough amps, you'd need at least 3 of those for a day's fishing at 18ah each.
 

4wings

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Just a thought (dons tin hat) an acquaintance powered his caravan with either golf cart or golf buggy batteries, I cannot remember which. Any good?
 

scobo

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Just a thought (dons tin hat) an acquaintance powered his caravan with either golf cart or golf buggy batteries, I cannot remember which. Any good?
Could do as long as they're rated around 40amps.
They're basically just smaller capacity leisure batteries so you'd probably need 2 or 3 of them though they'd be lighter and easier to carry.
Wouldn't really be any cheaper though, probably dearer. You'd want at least 2 of these providing they can do 40amps .......

 
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