Best 24v battery system for 24v leccy?

[GLXMAN]

Hi Guys
Starting to look at upgrading my leccy to a 24v and the usual research
Realise I could just use 2 x 12v batteries but wondered if a 24v battery would be a better option?

I guess charging the 2 x 12v would just be a "series parallel" when charging with a 24v?

Sorry, now 2 questions I guess !
.............Gary

[Dignity]

Haven't tried a single 24 volt battery, but something to consider, if using lead acid or AGM they all have 2volt cells, if one dies and you have 2 batteries you replace only one. Weight wise a 24 volt is a lot lighter usually in the mid 40kgs for a 150 amp or 2 x 33kg for 12 volt batteries.

If going LiPo4 then I'd definitely go a single 24 volt as there are all sorts of issues around charging albeit slowly being resolved.

If using lead/AGM have a look at Enerdrives site as there are some very good tips on cabling etc.

[NAGG]

Every time I asked this question - I was always advised to go with 2 x 12 volt batteries . Handling is one thing , replacing 1 battery if the need arises ( fault) is another - then we have the need for 24 volt battery chargers .

Now I don't know if what I have done is the best way to go & it is costly - but it's working well for me

I went with 2 x 100amp LiFePO4 batteries That have hardwired their own Victron 25amp on board charger which is isolated with their own 30amp breaker .
Aside from cutting the weight in half , I also have effectively a larger capacity due to the 90% DOD with little effect on the battery life .
As each battery has it's own charger pumping out 25amps - charging times are significantly faster ( a flat battery can get up to absorb in 3.5 hrs …. that's 95% full ) - this is important when I'm away , fishing consecutive days & in particularly if I have to run my generator .

Now Minn Kota advise against the use of Lithium batteries because of the higher voltage . That hasn't deterred though as many boats are running their MKs off LiFePO4s & have done so for years now.

Chris

[GLXMAN]

Thank you,
Sorry about the late reply, at Lucinda and caught a 24 hr bug.......on the mend now
Looks like lithium have come down in price, do like the weight drop!
.........Gary

[GLXMAN]

Much appreciated Chris,
As above, sorry for the late reply, caught a 24hr bug at Lucinda .........unfortunately not catching too many fish though, water still 21.5°C !
Thank you for the detailed information on the lithium batteries, sounds like the best option other than price!
.............Gary

[NAGG]

Much appreciated Chris,
As above, sorry for the late reply, caught a 24hr bug at Lucinda .........unfortunately not catching too many fish though, water still 21.5°C !
Thank you for the detailed information on the lithium batteries, sounds like the best option other than price!
.............Gary

Hi Gary

Yes , they are expensive as a per unit cost . The way I looked at it - it wasn't just $2000 vs $500 for a pair of 100amp LiFePO4 vs AGM . A better comparison would have been a pair of 170amp AGMs @ $800 ……. but here is the crunch 28kgs Vs 95kgs to obtain a similar run time on the leccy. Imagine how bow heavy that would be ? I know on my Seajay I had a 55kg 200amp AGM pretty well on the bow & it was a killer .

so yeh , there is more to it

chris

[myusernam]

So dont look at 2 100h lipos. Maybe 2 30 or 40 ah batts? Makes it a lot closer

[NAGG]

So dont look at 2 100h lipos. Maybe 2 30 or 40 ah batts? Makes it a lot closer

Unfortunately - not when you need decent battery capacity for say offshore spot locking

Chris

[GLXMAN]

Your right, didn't think of that, forgot about the combined AH!

[NAGG]

Your right, didn't think of that, forgot about the combined AH!

It really depends on how you use your leccy …… If you just mooch along a creek or river ( the odd spot lock) 2 x 100amp AGMs will more than suffice .
However if you are fishing strong tidal areas or in windy conditions - you will be down to 50% DOD in as quickly as 1 hr (50amp draw @ max ) ….. beyond that you are starting to degrade your battery. This is why I had a 200amp when I just had a 12 volt system.

For the last couple of years I've been doing a lot of offshore spot locking & even with the LiFePO4s I really can only get a full day out of them . The least was around 5 hrs last April at Lucinda out on the reef in 15-20knt winds. Hence why capacity needs to be considered & I know at some stage I'll be looking to go with bigger or add another couple of 100 amp LiFePO4s .

Back to the cheapest options - 120amp AGM would be the bare minimum & if weight isn't really an issue - I'd go with the slim 170amp Kickass AGMs ($738 / pair)

www.australiandirect.com.au/buy/kickass-12v-170ah-deep-cycle-agm-battery-twin-pack/3088509

[disorderly]

Have you heard any reports on these Chris.....https://www.aussiebatteries.com.au/b...-cycle-battery

Whats the advantage of that slimline style of battery you linked to …?

[NAGG]

Have you heard any reports on these Chris.....https://www.aussiebatteries.com.au/b...-cycle-battery

Whats the advantage of that slimline style of battery you linked to …?

Footprint - mainly …….I 'm running a pair of 120amp slim kickass in my Seajay where they are hard up against the bulkhead in the front hatch . This gives me some more room to fill up with other stuff .

[disorderly]

Gee its hard to make a decision on whats best and affordable...

Chris would you go 36v on your next one....?

Would I be right in thinking that using the bigger motor will actually result in longer run times for the batterys..

The 105lb motorguide is only $250 more and the 80lb and of course the cost of an extra battery....

I don't think the extra agm battery weight up the front will bother the boat too much...