My jump starter battery has given up the ghost and I'm looking for a replacement. I want to use it for the occasional jump start, but the main use will be for my caravan mover that I made using an ebay 12v winch motor which drags a reasonable amount of current (in excess of a 100amp}.
I believe the winch motor is a 2000lb or 2500lb rated motor but I cant be sure. I also want a battery that I can run led interior lights on my caravan for a few hours and also to run the electric outboard on my kayak for 3 or 4 hours. The outboard is a 24lb thrust watersnake with and electronic speed controller. My question is is there a battery out there that will handle all this and not sink the kayak with its weight. I have been checking out AGM batteries but the more I read the more confused I seem to get. Any input with advise will be appreciated.
I have four 26AH gel batteries, they are about 8.5kg each. So easier to move each one.
They are mostly for the fridge. Sometimes I run my 3 air compressors off them, about 90amps. Also have used them to jumpstart, myself once, & a handful of other cars. Using welding cable jumper leads.
Also great having masses of amps, abate less AH. When you draw very high amps the effective capacity of the battery is a lot less.
Four 26AH batteries will provide 360 amps, but all the batteries can provide is 5 minutes or 1040 for 5 second bursts.
Get the data sheet on the batteries, it has charging & discharging rates. They are quite comprehensive. If they can't provide it, look at a different make.
I have been shying away from lithium batteries because I don't believe that they can handle high discharge rates. I would like a lithium battery for the kayak but being a tightwad I think their a bit expensive.
I might have to rethink my idea and get 2 batteries of different types. If I get a lithium for the kayak it will be nice and light but then I will need to get another battery charger as well.
Pete
I jumpstarted a neighbours Audi, twice! First time I told them they needed a new battery, it was down to 7 volts. The Audi was a 6 cylinder diesel & according to Kyoritsu 2046 clamp meter needed 360 amps to start through my welding cables.
The four 26AH batteries laughed at this. Another neighbour had tried to jumpstart, but with no luck.
Unless you have a seriously massive lithium set-up forget it.
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Procrastination, mankind's greatest labour saving device!
50L custom fuel rack 6x20W 100/20mppt 4x26Ah gel 28L super insulated fridge TPMS 3 ARB compressors heatsink fan cooled 4L tank aftercooler Air/water OCD cleaning 4 stage car acoustic insulation.
Like the two 50amp Anderson plugs per battery & same length wiring. You really need two plugs per battery (screwed my two to a piece of aluminium & then double sided taped to the side of the battery).
If a soldering iron is not large enough (I have two 120 watt irons), a heat gun is brilliant. I wind up my 2000 watt Bosch up to 630°C & it solders 175amps without a hint of an issue.
The Anderson 50amp plug WITH 6awg wire is 50amps hot plugged & a handy 120amps cold plugged (power turned off).
__________________
Procrastination, mankind's greatest labour saving device!
50L custom fuel rack 6x20W 100/20mppt 4x26Ah gel 28L super insulated fridge TPMS 3 ARB compressors heatsink fan cooled 4L tank aftercooler Air/water OCD cleaning 4 stage car acoustic insulation.
I have been shying away from lithium batteries because I don't believe that they can handle high discharge rates. I would like a lithium battery for the kayak but being a tightwad I think their a bit expensive.
I might have to rethink my idea and get 2 batteries of different types. If I get a lithium for the kayak it will be nice and light but then I will need to get another battery charger as well. Pete
I use a 60amp lithium I made from Winston cells to power the electric motor in my boat for the last 10 years and still going strong. The battery even worked under salt water for 60 minutes to pump out the boat half full of water.
A 40 amp lithium should be able to handle a kayak.
Hmm I made up a 12v portable power supply and jump starter many years ago, by fitting two lithium batteries in a battery box with some external terminals and a ciggy socket. Not sure now but two 40Ah just straight batteries with no BMS. Similar setup to those battery boxes you can buy easily now. I used two because I wanted to be able to jump start an automatic 24V motor home and made it so I could quickly rewire it from 12V to 24V for starting the diesel truck motor in an emergency. It would do that easy but I never needed it !
I have jump started lots of other peoples cars, rucks, dead cars I bought, used it for running the TV/lights/laptop outside, running 3 way fridge, used it in a rental house for 12 mts running the 12V TV inside and the laptop and phones and lots of useful things like that. It has been used as a battery for cars that had no battery and were driven using it tied in the front. No problems ever and I do not have a special charger, just use my solar panels or clip on an ideling cars battery for a while or use an old 4A LA 240v charger I have had for years.
It is working well still and it is OK to carry one handed and lift on to an engine etc. It has no BMS on the batteries or in the box. It would be about 8 years old now and I detect no deterioration in the limited use it now gets. I have been going to break it into two units for our two vehicles as two jump starters with short leads from old dead LA jump start units. Each battery will easily start my 2.9tr diesel.
They were expensive back then to buy but much cheaper now.
