Phoenix of Hamble
Well-Known Member
Yep, with the advent of VSRs or smart alternator controllers, the risk of not correctly charging, or accidentally disconnecting alternators and blowing diodes seems, thankfully, to be a thing of the past!
Different battery readings
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rob2
Well-Known Member
So many posts contributing very little!
Consider that the two batteries can be viewed separately - only with the switch at "both" are they paralleled. Also, consider that the wiring can be considered as in and out senses. Your battery 1 is charging successfully from the solar panel, hence the raised voltage. If you disconnected the panel and waited a few hours for the surface charge to dissipate, then the voltage would drop to something much closer to that of battery 2. The failure to start the engine from battery 1 may be coincidental, but suggests that there is a bad connection frm that battery to the engine which battery two isn't suffering. Therefore the failure is either with the connections from battery 1 to the switch or within the switch itself. Some designs of switch are better than others, but if the contacts are not well aligned in the switch you can select the battery but the contacts are only making a high resistance connection so it won't carry the current for a start.
Check all the connections around the switch. No - actually unfasten, clean, grease and remake them all and your problems should disappear.
The only other likely candidate is that battery 1 could be on its last legs, so whilst you still see the surface charge from the panel, it hasn't got the capacity for an engine start. This is unlikely unless you have observed problems over a period, but batteries have been known to die quite suddenly.
Rob.
Consider that the two batteries can be viewed separately - only with the switch at "both" are they paralleled. Also, consider that the wiring can be considered as in and out senses. Your battery 1 is charging successfully from the solar panel, hence the raised voltage. If you disconnected the panel and waited a few hours for the surface charge to dissipate, then the voltage would drop to something much closer to that of battery 2. The failure to start the engine from battery 1 may be coincidental, but suggests that there is a bad connection frm that battery to the engine which battery two isn't suffering. Therefore the failure is either with the connections from battery 1 to the switch or within the switch itself. Some designs of switch are better than others, but if the contacts are not well aligned in the switch you can select the battery but the contacts are only making a high resistance connection so it won't carry the current for a start.
Check all the connections around the switch. No - actually unfasten, clean, grease and remake them all and your problems should disappear.
The only other likely candidate is that battery 1 could be on its last legs, so whilst you still see the surface charge from the panel, it hasn't got the capacity for an engine start. This is unlikely unless you have observed problems over a period, but batteries have been known to die quite suddenly.
Rob.
+1
I did have very old fashioned single switches, you may remember me, your assistance and that of VicS was most helpfull in my hour of need, those switches were a part of the problem, their age was anyway as they, or one was, in effect a bad connection. I replaced with a modern 1, 2, both, switch, which certainly helped, they do the same job as previously, that is I used to select the starter switch to start and then switch to the domestic, and switch off the starter one.
I was regimented to do this, and continue in the same vein with the new one. I much prefer to have a manual system which I follow each time, its the KISS principle I think.
Isn't that exactly what a 1-2-both does surely.
Would welcome comments made here http://www.adverc.co.uk/batterymanagement/split-charging-systems about VSR and their recommendations for an Adverc.system.
Picks
Active Member
Check all the connections around the switch. No - actually unfasten, clean, grease and remake them all and your problems should disappear.*
Thanks for all the replies and discussion. Looks like next time I get to my boat I'll remove, clean, grease and reconnect. Do I need special electrical grease ( contralube ) or will vaseline do?
Cheers
Thanks for all the replies and discussion. Looks like next time I get to my boat I'll remove, clean, grease and reconnect. Do I need special electrical grease ( contralube ) or will vaseline do?
Cheers
VicS
Well-Known Member
He is getting the high voltage reading on B1 because its being charged from the solar panel
The lowish reading on B2 is because its its partly discharged, or has recently been loaded or maybe past its best.
The engine would not start on B1 because theres a bad connection somewhere.
It started on B2 because it was OK despite the lowish voltage reading.
Storyline
Well-Known Member
To continue the two threads in one theme, I prefer the 1, both, 2 system so I can charge each battery bank independently, and more importantly easily see which bank is being charged. If it is a good sailing day I want all the output of the alternator to go to the house batteries even though the engine battery is not completely charged. I know it will be full enough to start the engine and not suffer any harm but 20 minutes motoring might be enough to bring the house bank back up from a level that might not be healthy for it. Two switches could achieve the same I suppose but I prefer one !