Adding second battery

[Castro]

I was thinking of adding a second battery in parallel and came across this.


2batt.jpg

I hadn't thought about the fact that if I didn't do this the life of battery B would be reduced in such a way (traditional parallel configuration )duel battery.jpg. Has anyone else added a second battery to increase capacity?

[BW3]

I just got done doing this same project,I got a marine axillery battery kit ,what is nice about it is that you have the choice of using one or both batteries to start but can isolate one for assecories and still have both batteries charging. You can even shut both batteries off from the system if you have a drew issue to save them . Kit comes with a switch and an isolation relay. If you want I can get photos taken and post to my gallery. Kits and or needed parts are available from a couple of companies and both given good instructions on how to wire ....
bg

[Castro]

please post them here!

[BW3]

I used Blue Sea add a battery mini 65 amp system and another company's switch due to my local marine shop did not have the full kit in stock so I got what they had and wired it per the instruction (check out Bluesea.com or YouTube search same ). Will post photos asap .. ps. It is not cheap but it works very well for what it does that is to give me the choice to run an electric trolling motor with recharge available or to have a second battery in circuit for starting if needed .

[tbone9]

I also added a second battery to run my way too big light bar. I used a smart switch to keep the two separate but yet still charge the auxiliary battery only after the start battery is fully charged. Got this idea somewhere on here. So far so good. I like the fact you have more options with your set up and being able to shut everything off or run one or both. Look forward to the pictures.

[trevorakm1]

Castro where are you thinking of mounting the second battery in you bigfoot? I like the idea of dual batteries.

[BW3]

Oops , cat stepped on keyboard and sent this post and Photos to the ends of the internet , please delete and carry on with the corrected post below

[BW3]

,,,, Took a bit but here are the photos and wire diagram I used , works great .. Good Luck .. BG

[Castro]

Looks great. I was thinking about a pair of Alien Motion LifePo4 batteries mounted in the same location, one flipped upside down. I have used these in other toys and they are amazing. My father was selling them from his shop at one time and I became a fan. I had one in my 4 wheeler. left it unattended for two years. still had plenty of charge, but I wore it down to nothing, and left it for another 6 months. after this winter grabbed it and figured it was junk, but the old man said it would be fine. he used their smart charger and its as good as new. Anyone have any opinions on this type of battery?

[Castro]

these are pretty cool as well


Lithium battery replacement for automobiles and motorcycles

[BW3]

Stock Argo battery per the parts list is Exide 45 60 specs about Cca of 525 ...... I have no clue if the battery your looking at will work but If I was going to try it the 500 or 600 amp series would be the ones I would try but this is only a guess ..... Not sure what you are trying to get by going to a lighter battery and possible limiting draw time , if you are using a winch this will be a very big factor if I understand the lithium batteries are not happy if drawn down/killed over and over to many times or left at low charge for a long time but I could be mistaken ....opinion given that and 2dollars will get you a cup of coffee...Good luck. happy trails ...Looked at the link ......$$$$ I think I will stick with the stock battery and a good deep cycle as my backup to rich for me ....wow .....jmho

[Castro]

so people using those batteries in say power drills would see super short life I would expect. They are lighter, and smaller, and my thinking was along the lines of cramming two into the orig location. I hadn't thought about the draw from the winch, I may have to do some more research. good thinking points, thank you

[tbone9]

I like the idea of the manual switch. Good idea.

[allwheeldrive]

To address the first image, sort of true. I mean I have hooked up multiple 18AH SLA cells in this configuration in order to (force equal discharge) but at the same time, I think it might just be superstition. In parallel factory batteries ( a battery simply is multiple cells in a configuration) they usually just wire them up + to + and draw all from one side. One battery is drained but the batteries piggybacking off of it restore its charge essentially as quickly as you can drain the first. I've run both configurations in plenty of homemade devices (high powered flashlights, scooters, lawnmowers, boats) and never seen any advantage or disadvantage either way. That said I ALWAYS charge in this configuration, that way you force all the parallel cells to take the current.

In the end it's not worth losing sleep over that said,

The idea of LifePo4 12 volt batteries scare the crap out of me.
Battery cells range between LifePo 3.2 and Li-po and Li-ion 3.7 volts a cells, Lead acid is 2 volts, while alkaline 1.5 and Nimh 1.2 volts
This isn't really relevant, but simply a 12 volt battery is made from multiple cells to get the operational 13-15 volt range. All other chemistries play nice in parallel and series connection, except Lithium. Lithium cells become unbalanced in their packs and extremely volatile if they are not maintained at the same voltage. The best example is Cell phones and laptops take in power from your charger and distribute it equally between the internal cells to maintain constancy. Hi power Li-po packs for RC cars etc have separate balancing leads that connect up with every cell in the pack when charged IE a 14.4 volt pack will have 4 cells and 4 extra wires to keep all the cells happy.

unless these LifePo car batteries have some sort of internal smart distribution computer I would be very worried that over months of use the cells could get unbalanced and one overheats, over discharges, or over charges and the next thing you have is a 12 pounds of explosives packed into your Argo. I run Lithium batteries in nearly everything My Coot even ran a Li-po pack for its engine fan, but these don’t get charged by a “dumb” 12 volt alternator.

[Castro]

its worked great in my Honda 400 ex for years. never had an issue.