Leisure Battery and ECU Problem

[Jockyboy]

Hello to all . I have a 2005 Swift Kontiki 610 Low Profile and just been doing my usual pre winter check. I should say at the outset we are still amateurs re van electrics despite having driven around Europe and the Middle East over the past decade or so. Anyway ,to my surprise, the leisure battery reading was very low and hardly any power when turning the pump on. I suspected the leisure battery/ batteries having died but just to make sure we gave it a 12 hour on board charge and the readings rose again to around the usual 13.4 .
We have a solar panel and 2 Trojan 27TMX leisure batteries . The Remote meter display showed battery 2 was completely dead and had a red light .We disconnected the oldest battery suspecting this to be the culprit. However this made no change to the 13.4 reading we were getting on the ECU.We reconnected said battery and then disconnected the 2nd battery but again the ECU reading remained 13.4 . When we subsequently turned on the taps , there was insufficient power from the pump to provide more than a trickle. 10 mins later, the pump was firing up as normal with a strong flow from the taps.
Finally, we disconnected and reconnected the ECU in case this was the cause of the problem. This was because the readings on the ECU were shifting up and down .
So we are at a loss as to the root of the problem . A battery load capacity test was recommended but I havent a clue as to the process for this ! I could gamble and just buy a replacement cheaper option than the Trojan or even been pondering buying 2 replacement 95ah batteries to reduce cost. Am hoping someone on here can suggest what is happening here or suggest what else we should be trying to diagnose the cause of the problem. Thank you in anticipation

 

[Bigshug]

Is the 13.4 volt reading with the solar disconnecte, Possibly the 13.4 volt reading is the solar charge, not the battery voltage. Try disconnecting the battery from the solar, then check the voltage.

 

[trevskoda]

You require a 14.4v charge to batts, after it floats at around 113.4/7v and with no charge a good batt will sit at 12.6/7v, but a discharge with a clamp meter or heavy load will tell if it has the current, other wise it may be bu--ered..

 

[QFour]

You need a simple multimeter to sort it out. You can eliminate the solar effect by checking after the sun goes down or pulling the wire from the solar to the controller. Disconnect the link to the two batteries and check the voltages of each battery. They should be around 12.7 volts. If one battery is faulty it is probably dragging the other one down as well. Batteries should be replaced in pairs. You need to check the voltage coming from the solar controller. When ours packed up it was putting 17v into the battery. Then check the voltage coming from the battery charger. If its a Sargant system it could be a faulty charger. If you take the batteries out and fully charge them you can get them checked at local battery outlet.

 

[rugbyken]

you say you “suspected the leisure battery had died “ if that is because you know they’re old, think you should just bite the bullet change them at your convenience rather than have them let you down at the most awkward moment ,

 

[Molly 3]

Have you checked water levels in your battery , if you do change you batterys consider lead carbon , do a little research to see if they meet your needs . Check your battery voltage individually , both batterys disconnected ,one battery could be ok and one not ,

 

[maingate]

Trojan batteries have had a reputation in the past for needing regular top ups of distilled water. Also, when they fail, they can fail abruptly.

If I were you I would remove one battery connect a power source (a 12 volt light, a 12 volt fan) and check the voltage at set intervals. Do the same with the other battery. If one is dud you need to renew both.