Advice on battery charging

[alfonso]

ok hopefully this will be my last question . Now as said I have a 150 amp regulator in car going to battery in back of ute ,Then I have cable running to rear of vehicle to Anderson plug from house battery pos only neg to chassis . As stated before I will be putting mppt regulator in vehicle for solar charging min 20 amp perminantly fixed . Now my question is can I put a dc to dc regulator with mppt in caravan to boost charge or will this not work with existing regulator in vehicle as they will be in line with each other my reason for all this is that I use different vehicles for towing and also use ute on its own mostly. As I only recently installed the regulator in vehicle I am loath to change it if possible. And if I use another vehicle for towing caravan Mercedes sprinter with just Anderson plug to cranking battery , i need to have a regulator in caravan with mppt for solar also This is my conundrum. So in effect when towing with ute i will be charging cranking battery then to regulator after which house battery in ute then to Anderson connections followed by dc dc charger next to 2 house batteries in caravan. All house batteries are 120 amp hour agm . Sorry for all the babble but this is how it sits in my muddled mind Thanks again Alf Ps have just worked out how to put map of installation on here so will draw one up tomorrow

[Cuppa]

1. i think you mean 150 amp relay (VSR -Voltage sensitive relay)?
2. Sounds like you want to 'daisy chain' alternator- crank battery-VSR-ute aux battery- DC to Dc charger- van battery?
3. A diagram would help.

Have not seen 2 done. Not sure how well it would work. It would certainly complicate any fault finding if a problem arose. For similar setups I've seen Redarc recommend alt -crank battery - VSR - Ute aux battery AND SEPARATELY crank battery - dc to dc charger -van battery. I reckon for the sake of a bit more wire keeping them separate would be worthwhile. when I bought my vehicle it had a dual battery system in it, utilising a VSR which I nitially intended to retain, plus adding more 'house' batteries. Redarc advised me as I have advised you.
In this instance the dc to dc charger would be mounted in the van as close to the van batteries as possible. it would make sense to use a combined dc to dc charger & solar regulator like Redarc's BCDC1225.

I would suggest NOT using the chassis for earth, but instead run dual cable. Again simplifies future fault finding. Remember that cable sizing should match the total length of positive & negative cables. http://hobohome.com/news/?p=581


Cuppa

[alfonso]

Thanks cuppa now that makes complete sense it is perfect for my needs you are a legend . hope my stones in sill theory works as well for you Alf

[FNQGU]

Cuppa, thanks for the diagrams. I particularly like your idea of a manual 3-way switch to allow charging of the starter battery from your panels / AC source. I am currently considering installing either a BMS or simply a BCDC to manage the house battery, and have been contemplating the whole management of the starter battery at the same time. For me it has been a problem as I am away with work for a month at a time, and have in the past found the start battery nearly flat when I come home. To combat this, I have been leaving a small C-tek 7Amp charger connected, which has worked well and has kept both batteries in good condition via a VSR, and I would like to continue this practice.

My house battery has until recently been a 66Ahr Optima Blue Top, which was not really a good choice. Great battery, but not for this purpose. It is now a 105Ahr Full River AGM. I changed it after I had a bit of a scare on a recent trip when using the stereo for a moderate (I thought short) period of time, causing the starter battery (Optima Red top) to run down very quickly. This was compounded by a problem with the 240v plug from a generator to the Engel not working (faulty connection found later), and the fridge nearly flattening my house battery after two days camping. Suddenly I had almost no power to start the truck and was two and a half hours drive from the nearest help with a flat house battery that I would have relied on to jump start the starter battery (yes, I had the generator as my last contingency, but not the point really...). Luckily the Optima Batteries have pretty good cranking power and it still managed to start the engine, much to my relief.

I am now also looking to move the UHF and car stereo power sources from the starter across to the House battery for further peace of mind when camping remotely.

As my house battery is under the vehicle (passengers side), I am looking at mounting the BCDC inside the vehicle as mentioned in a previous thread, on the back side of the drawers (ie. behind the back seats), with a cable gland keeping water out where I drill a hole through the floor. Of interest, my local battery supplier highly recommended the Full River batteries, but said the BCDC40 would be too much for it, and rather the BCDC25 would be perfect.

I will probably also run a cable to the rear of the vehicle at this same time to use in the future for charging batteries in a camper from the alternator.

Where do you have this manual 3-way switch installed? I am guessing it is in the cab if you have it co-located with your winch connecting switch? Any chance of a pic?