'Gassing' batteries

Worth exploring 'Megapulse' for converting the (inevitable?) sulph build-up on the plates after the "abuse" you and your mate's batteries have received? (Mixed reviews, but cheap & may assist in more complete recovery??) Griff

Andy are your batteries the type that you can add electrolite to. My calcium calcium batteries are fully sealed and nothing can be added. If your are not sealed does the specific gravity change in the different cells? Brian

Re Megapulse

I wrote a piece on this for the CMCA's 'The Wanderer' (I do a two/three page Tech Notes column there most months).

Briefly the CSIRO tests are inconclusive due to a sample population of only four (of which one was a control).

A very thorough German University test (or about 90 batteries) showed that the unit does effectively reverse sulphation if the batteries are not to far gone. The recovery is surprisingly good.

What one needs to consider of course is that a correctly charged and dischared battery suffers only very minor sulphation. If you use one correctly you don't need pulse technology. Secondly these things draw some current all the time - so they will only be effective over long periods if a battery charger is in use - in which case they are less likely to sulphate............

In other words their major value for most of us may be to fix already abused batteries.

Don't dismiss the technology per se - it is now being incorporated into chargers and electrical systems for electric vehicles and is being lookled at for the forthcoming 36/42 volt vehicle systems.
Collyn Rivers

Andy

Most batteries begin gassing at about 14.3 volts - where current is usually only a few amps from most charging sources.

If the charger permits I would run them up as high as 15 volts for about two hours - they'll be noisy and seemingly boiling - but it will do them a world of good - but don't keep them 'boiling' not longer than two hours and be ultra careful with anything likely to ignite the gas.

Unusual to see gassing at 13 - have you checked the SGs? If so what are they? .

These cal batteries generally fine.

Would seriously consider installing that three-step charger. Almost every battery maker world endorses their use.
Collyn Rivers

Andy , I still say it is the charger. My batteries are the same as yours and are probably around same age ... mine 22 months. My batteries seem fine ... had electrolyte on top once that was wiped up with 1/2 a paper towel. Mine are charged by the solar 99% of the time as I get enough light under the roof to kick in the solar regulator. I have topped them up once in that time (last Christmas) level was down maybe 8-10mm. I checked the level two weeks ago and is still good. It looks like it is the people using the BT charger frequently with that battery that are having the problem ? Are your batteries damaged now ? Anthony

Collyn We have been in Agnes Water for the last 10 days hence my delayed response to your last posting. The little 6 Amp Charger puts out about 14.4 volts, as for the SG of the electrolyte, my hydrometer is in "green", "white" & "red" segments & with the batteries, which are still out of the van, charged I am at about the the "white"/"green" interface. After 10 days standing the batteries were all at 12.75 Volts but how many Amp Hours only time will tell. We plan to install a multi-stage charger but my real concern is acid. When I opened the box which contains all three batteries (under the bed) there was electrolte mist on the tops of the batteries. Not a huge quantity but perhaps any is too much for comfort. Given that the box is wood I am a bit concerned about its longevity. Does the solar unit, which charges at between 15-20Amps & about 14.4 Volts cause a bit of electrolyte mist or is it only the BT Charger? Will a multi-stage charger ameliorate my concern? Andy

Andy, I spoke to Steve Gibbs about batteries about 2 weeks ago and it is his belief that they were supplied with a bad batch of batteries as they have had a lot with similar problems. That type of battery apparently is no longer available from AC Delco. I believe Steve said that a lot had been replaced under warranty. As you are at Agnes Waters, it may be worth taking the van with batteries down to Bushtracker for a warranty claim. My batteries packed up at Wiluna and I drove 800km each way to Geralton to get them changed under warranty. The fully sealed type work a lot better and I believe are a lot safer inside an enclosed area such as a caravan. Brian.

Andy, What size BT Charger have you got. They have told me that for 3 batteries they now recommend 35Amp and 4 batteries 50amp chargers. The older 25 amp chargers apparently take too long to put their charge in and because they are charging for a long time heat up and cause gassing. I could have it wrong but it was something like that the electrician told me 18months ago when we had problems. We now have a new 50amp charger the appears top be woking well. Interesting to see what Meg had to say about the other Bushtrackers having battery problems. No wonder BT have changed their supplier, they wouldn't appreciate the negative comments about batteries that they don't really have much control over. Brian.

Andy
If your batteries are at 12.75 volts after 10 days, they are very well charged indeed and in good shape. Do not be concerned that the hydrometer reading is not higher than the white/green interface. Deep cycle batteries are usually filled with a slightly lower specific gravity electrolyte than starter batteries - and most hydrometers are calibrated for the latter.

In my opinion ANY non-regulated battery charger is a potential battery wrecker. They are fine if carefully monitored for overcharging - not otherwise.

Ideall the charger should be capable of putting out at least 15% of total battery A/hr capacity, otherwise charging takes too long.

Re excess gassing through too low charge rates. Gassing does not set in below 65-7% full charge and when it does the gas emitted is a direct function of amp/hours. Thus a 5 amp charge over 10 hour (once over say 65% charge) will result in the same amount of gassing as 10 amps over five hours.

If using a battery charger to the extent that BT owners do I would ONLY consider a really good three-step charger. These inherently charge much faster and deeper than normal chargers. A 20 amp three-step charger will outperform most 40 amp normal chargers. They can be left permanently connected and switched on. Almost every battery maker in the world endorses their use.

The down side is cost. Thse things are not cheap, but nor are battery replacements. A three-step charger will normally extend battery longevity by a fair amount.
Trust this helps
Collyn



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Collyn, It is great to have your knowledge on this site. Much better getting it straight from the horses mouth than by all the other back door methods and loosing bits in the translation. On behalf of the others, thanks for your help. Brian

Brian Are your replacement batteries AC Delco M27NF? Does anyone know these batteries? Anthony Collyn's comment has convinced me to proceed with the Victron Phoenix Charger 12/30 - will be away for a few days from Thursday, will contact you when I get back. Collyn Thanks for your input into this (on-going) saga - I am slowly reaching a resolution - your advice has been much appreciated. All When I contacted Steve at BT re this issue & he was most helpful. Despite the little challanges, we have never regretted the selection of the BT & in our case have not recieved anything but positive & personalised help when we have contacted BT. Andy

Andy My Batteries are AC Delco Voyager model number M27MF. Maybe they might have a new model out now seeing as the number you quoted is NF instead of MF. Brian

Thank you for your comments everyone.
Collyn