Dual Batteries and VSR

[DieselBoy]

Hi guys,

I'm pretty ignorant with eletrical stuff, i know just enough to be dangerous

I am busy setting my truck up to power an electric winch "properly".

I have a 110amp alternator, and two batteries.

One battery is a standard NS70, and the other is a M27MS which is a 720cca marine deep cycle battery, and is about the same size as a NS70Z.

My plan was to just run these two batteries in parralelle. Simply because i wanted the power from both for running the winch, and wasn't worried about making sure i had a fully charged battery for starting, idoub't the two of them would ever get that flat.

Then i got thinking.................................

with two different batteries, what happens when i start drawing them down using the winch??

So if they are wire in parralelle, will the NS70 run flat earlier than the M27, therefore potentially killing it, while the M27 can handle it??

Then there's the charging, the Ns70 will recover far faster than the M27, so once the NS70 is charged, will it get over charged whilst the M27 is finishing topping its self up???

Okay, then enter the VSR (voltage sensitive relay).

If i were to incorporate a voltage sensitive relay, i would have to change my layout, and not run the batteries in parralelle.

I would have to have the NS70 hooked to the starter as the main feed for the engine and other vehicle systems, and the M27 as a stand alone battery soley for the winch.

By doing that, the NS70 does not supply any support during winching, and unless the NS70 battery is 100% fully charged, the VSR will not allow any supporting charge through to the battery that is doing all the winch work.

I personally favour the idea of both batteries sharing the load, wired directly in parralelle, but due to space limitations, i have no room for two M27's.

I could fit two standard NS70's though, but i would loose my deep cycle battery.

So like i said earlier, if i wired the normal and deep cycle battery in parralelle, will it create problems as they are two completely different batteries??

Cheers,
Pete.

[Sadam_Husain]

Okay, then enter the VSR (voltage sensitive relay).

If i were to incorporate a voltage sensitive relay, i would have to change my layout, and not run the batteries in parralelle.

Most of all that stuff was over my head as well but the way I see the VSR part is if the engine is running and the alt is charging the VSR contacts would be closed putting both batteries in parralell anyway?

[red-devil]

DB my vx is a 24 volt start 12 volt run
so if your truck is the same you cant run i parallel.

but if you have installed the second battery then. the NS70 will dischage a little quicker then the deep cycle but it will die as the deep will handle it better.

VSR work like a switch charages the start battery once charge to 13.8 it then starts on the other battery. but as you have both connected in parallel it will be tryin to charge both batteris at the same time.

VSR only works when you have a start battery and a house battery.

Jono

[Shane]

best to have both batterys the same and run in parallel ,but pretty sure you already know that and are using what batterys you have.

You could run the VSR for normal use and have a heavy rely that by-passes the VSR connecting both batterys for winching and switches off again when winching stops.(a rely like the safari has on factory elect winch set up,located in front of right side battery)
If you run batterys down on a long winch you may not get charge in the deep/c batt for some time depending how good you alternator is,needs to charge over 13.8 to juice up second battery,which may not be ideal

Shane