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Wednesday, 28 January 2015

Slow Charge

I've had the boat battery on charge for a few days now and its just about struggled to 13.3 volts. It looks like its been disconnected from the solar panel for a couple of weeks and the bad news is it may not recover fully.

I might have to bite the bullet and buy a new battery. :-(

I may have to use my contacts and see how cheap I can get a leisure battery. But not before I fit a solar charging regulator.


  1. That's a shame - sure you need a regulator though? How big's your panel? I read that you apply the 1:10 rule (Wattage to Amp hours) so a 10 watt panel could feed a 100+ amp hour battery without needing one...???

  2. Have you done a discharge test on the battery? If you go down the new battery route, I would be interested to see what type you finally go for. Was the battery already in bad condition? There is a lot on the net about battery desulphators but I have never bought one as there is no real reliable information about them.

  3. Steve, its a 10W solar panel and a 75 Ah battery, so its possibly been overcharging. Plus when the battery has been discharging, at least a solar controller will disconnect the load when the battery voltage drops below a pre-set voltage so it won't drop any further.

    Anon, I've not yet done a discharge test, its only just crept up to 13.8v and it's taken the best part of a week to do that. Hopefully the charger is doing its stuff and by this weekend the acceptance charge phase will be over and the battery will be fully charged. Then I can test the battery. The charger is an intelligent one and I've set it on the mode you use to recover batteries, so I'll see if it works in a few days.