I have 2 x 100amp batteries in my van - wired + to + and - to - - ie to give 200amp 12v.
Q1 - Should the onboard battery charger and the Solar Panel regulator be connected to the one battery or + on one and - on the other?
Q2 - Would it be better to have a DC to DC charger between them rather than hard wired?
Thanks
Glen
Aus-Kiwi said
09:47 PM Sep 19, 2016
To solar over both batteries. I guess they are parallel wired for 12v ? Depends on regulator ? If it's 24v then yes connect series as in 24 v lighter cable required . But IMO would keep it the same as supply ., depends what you use ? These days we tend to buy appliances which run on 12v DC direct . So other than microwave, elect jug . The inverter is not used as much ..
oldtrack123 said
10:57 PM Sep 19, 2016
Q1
It will not make any real difference which way you go provided ALL connections to the batteries are clean metal to metal contact &are tight
[2]Why are even considering a DC DC charger??????
What do you hope to gain??
Treecrest14 said
09:25 AM Sep 20, 2016
The background:
I had the charger wired to the + on 1 and the - on the other. But then got to thinking it might be better to connect the charger to the one battery. Anyway now noticing that the battery seems to be slowly discharging, and can't find any item/appliance switched on (except a volt meter which is connected to the batteries)! Hence the questions..
DC to DC was grasping at straws as to why the slow discharge.
oldtrack123 said
11:20 AM Sep 20, 2016
It could be that one or both of the batteries has high internal leakage [self discharge] it would also pull the other one down Suggest you either get them both tested or do a simple check yourself by: [1[ disconnect the batteries from each other & any load [2]fully charge each individually [3]disconnect charger from battery, let stand for a few hours then check voltage [4]recheck voltage after say 24 hours
if either shows much less than 12.6/12.7v it could be the problem.[n any case come back with those readings
[a]Is this a problem that has suddenly occurred?
Are they van batteries??
[c]Over what period do time do they discharge & to what voltage?
[d]Amphr rating of each?
-- Edited by oldtrack123 on Tuesday 20th of September 2016 11:26:59 AM
Aus-Kiwi said
11:59 AM Sep 20, 2016
If they are bridged to be 12v ? Both will charge anyway . My assumption on DC 2 DC is when you have batteries some distance away and cables MAY have voltage drop over distance . So increasing voltage ( pressure) is one simple step . As you need higher volts to charge another battery . 12v can be very lazy .. Think of the old cars with 6 volt systems ? Sheesh !! Lower volts / higher amps to do same.. Always proportional ..
macka17 said
01:15 PM Oct 25, 2016
Stop at a battery/tyreplace on travels.
Get them to do a "load test" on each battery.
Most will.
Simple. quick and will tell you what each battery is. usage wise.
Do same on car batt at same time too.
Everything deteriorates. even you (me. us.)
Could also be that you don't have or not giving enough input from solar too.
2 x 100a Battery's.
you'll need around 340w of panels Minimum...to maintain capacity.
and that's up here in the North.
More down South.
Wire Pos to Pos. and Neg to Neg. , then pos/neg to van wiring/fuses..
Regulator to the single Pos/neg wired that come from there.
Closest to battery's.
AC Charger to same Battery connections in boot/battery space.
Genny in tray or boot of car for bad times.
Peter_n_Margaret said
05:46 PM Oct 25, 2016
oldtrack123 wrote:
It could be that one or both of the batteries has high internal leakage [self discharge] it would also pull the other one down Suggest you either get them both tested or do a simple check yourself by: [1[ disconnect the batteries from each other & any load [2]fully charge each individually [3]disconnect charger from battery, let stand for a few hours then check voltage [4]recheck voltage after say 24 hours
if either shows much less than 12.6/12.7v it could be the problem.[n any case come back with those readings
[a]Is this a problem that has suddenly occurred?
Are they van batteries??
[c]Over what period do time do they discharge & to what voltage?
[d]Amphr rating of each?
Take note of what Peter said above...
Battery testing by retailers is useful to determine the crank capability of a battery. It is not necessarily relevant or useful to indicating the condition of lower recombination rate house batteries.
Cheers,
Peter
Aus-Kiwi said
07:39 PM Oct 25, 2016
Trouble is SOME say battery is buggered when it isn't !! Well ? I got another 3 years out of one set . Even then sold on .,'
I have 2 x 100amp batteries in my van - wired + to + and - to - - ie to give 200amp 12v.
Q1 - Should the onboard battery charger and the Solar Panel regulator be connected to the one battery or + on one and - on the other?
Q2 - Would it be better to have a DC to DC charger between them rather than hard wired?
Thanks
Glen
Q1
It will not make any real difference which way you go provided ALL connections to the batteries are clean metal to metal contact &are tight
[2]Why are even considering a DC DC charger??????
What do you hope to gain??
I had the charger wired to the + on 1 and the - on the other. But then got to thinking it might be better to connect the charger to the one battery. Anyway now noticing that the battery seems to be slowly discharging, and can't find any item/appliance switched on (except a volt meter which is connected to the batteries)! Hence the questions..
DC to DC was grasping at straws as to why the slow discharge.
It could be that one or both of the batteries has high internal leakage [self discharge] it would also pull the other one down
Suggest you either get them both tested or do a simple check yourself by:
[1[ disconnect the batteries from each other & any load
[2]fully charge each individually
[3]disconnect charger from battery, let stand for a few hours then check voltage
[4]recheck voltage after say 24 hours
if either shows much less than 12.6/12.7v it could be the problem.[n any case come back with those readings
[a]Is this a problem that has suddenly occurred?
Are they van batteries??
[c]Over what period do time do they discharge & to what voltage?
[d]Amphr rating of each?
-- Edited by oldtrack123 on Tuesday 20th of September 2016 11:26:59 AM
Get them to do a "load test" on each battery.
Most will.
Simple. quick and will tell you what each battery is. usage wise.
Do same on car batt at same time too.
Everything deteriorates. even you (me. us.)
Could also be that you don't have or not giving enough input from solar too.
2 x 100a Battery's.
you'll need around 340w of panels Minimum...to maintain capacity.
and that's up here in the North.
More down South.
Wire Pos to Pos. and Neg to Neg. , then pos/neg to van wiring/fuses..
Regulator to the single Pos/neg wired that come from there.
Closest to battery's.
AC Charger to same Battery connections in boot/battery space.
Genny in tray or boot of car for bad times.
Take note of what Peter said above...
Battery testing by retailers is useful to determine the crank capability of a battery. It is not necessarily relevant or useful to indicating the condition of lower recombination rate house batteries.
Cheers,
Peter