'Boiling' Batteries

Submitted: Tuesday, Jul 22, 2003 at 06:59
ThreadID: 120031 Views:8782 Replies:15 FollowUps:0
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I had a phone call last week from a BT Owner I met eighteen months ago & ran into again earlier this year, he & his wife live in their BT, about batteries. He was not holding voltage & when he delved into the "maintenance free" batteries he found pretty well all the plates were visible. He phoned me because I had mentioned the problem of seriously boiling batteries experienced by another BT Owner. That is another story. Anyway this led me this afternoon to open our battery box, viz a wooden box containing three A/C delco MRV27's with a screwed-on lid located under the island bed. Bit of a problem! Much fine acid visible, particularly on top of the centre battery. I pulled out all three batteries out & found electrolyte was down in all, in the middle unit the plates were visible! Co-incidentally I have been reading about Battery Chargers as we have two vehicles which are both fitted with Alarms, one with a Rotronics unit & the F250 to be fitted with same next Thursday. This "live" electronics load, combined with the fact that we do not use either vehicle sometimes for a week or three or more, I shop on a little Yamaha Zuma & our Daughter is living with us & we often use her car, means that we really need to put a charger on the vehicles on a regular basis. What has come though in this area is that we will need a Regulated Voltage Unit of at least three stages, the last of which is a trickle charge. Cost $400 - $700. The problem with the BT batteries, which is pretty damn serious, then led me to take a close look at the Generic BT Charger fitted to the van. Lo & behold, it Boost Charges & Charges, no mention of Float or Trickle Charge let alone Regulated Voltage. We do not always park in the sun & often use the BT installed Charger to keep the batteries up. Additionally when we are off the road we park in our garage, no solar so use the BT Charger. It would seem to me that this (BT Charger) unit is dicey to the point of danderous as it must keep on pumping in Charge regardless of battery voltage, hence the loss of electrolyte. This assumption may be wrong but there has to be an explaination for the batteries boiling dry & I can see no other. We intend to fit a Regulated Voltage three or four stage unit which it seems will cost $800 - $900. My advice to all who use the BT Charger a fair bit is to check the Electrolyte level ASAP. To those with vans on order - supply your own high quality Regulated Voltage Multi Stage Charger. I would appreciate any comments or advice. Andy
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Reply By: Deleted User - Tuesday, Jul 22, 2003 at 07:37

Tuesday, Jul 22, 2003 at 07:37

Something like that except would like to see much larger top vent. Again cannot suggest a minimum for obvious legal implications. Your wife's ideas seem excellent except why not use a piece of heavy galvanised or stainless mesh?.

You'd certainly need to seal the box to the interior - not just against gas but also to prevent your filling the area with sand.

I'd personally feel happier with the batteries external - but you are adding a lot to the polar moment of inertia if they are out on the drawbar. Remember their 'effective weight re pitching' is proportional to their distance from the van's centre of mass (probably just ahead of the axle or axle group). It's not a linear thing.
AnswerID: 559198

Reply By: Andy1 - Tuesday, Jul 22, 2003 at 07:38

Tuesday, Jul 22, 2003 at 07:38
I think we have drifted off the original reason for my posting, to warn everyone who has their batteries in a sealed box under the bed to check the electrolyte level & for those with vans on order to supply their own (quality-voltage regulated) Multi-stage Charger. I have a very chear Super Cheap Auto's PRO USBR BCH6 (Amp) Battery Charger which I use occasionally to charge boat & car batteries - always after removing same from vehicle. Stated on the little sheet that comes with this charger is this gem, ""FLOAT CHARGE" ensures that the charger will automatically stop charging at a point where there is no problem in leaving it permanently connected to the battery". While we were away for a few days I left the Charger on a BT A/C Delco battery on "FLOAT CHARGE", arriving home this afternoon several cells were gassing like hell. My belief is that this is exactly what happens with the generic BT Charger if left on. Heaps of gassing! Hence my mates problem. Just as an aside on this Hydrogen/Oxygen explosive mixture which is the product of gassing, there is a plastic venting tube (top & bottom) in the battery box, in our case Jude noticed that where the top tube leaves the hold at 90 degrees it was folded closed - no venting! I just fitted one of those black plastic garden irrigation elbows - problem solved. I did advise BT & it may pay anyone with this configuration to just check that their vent hose is closed at the 90 degree bend. Andy
AnswerID: 559199

Reply By: Deleted User - Tuesday, Jul 22, 2003 at 07:39

Tuesday, Jul 22, 2003 at 07:39
Hi Andy, we (Geoff and Pam), have had lots of trouble with our 3 batteries (A/C Delco MRV27) boiling on us during our trip from Sydney to Cooktown and back. Our Prosine 1000 inverter broke down. We were to discover there had been a manufacturing fault - a part inside had come loose and Bushtracker replaced the inverter and had it installed while we were in Cairns at no cost to us. The technician working on this informed us that our batteries were boiling. We have a 25amp. Interacter charger - 3 stage ? There are three 120 solar panels on the van. We tow our van with a Toyota 4.5l. petrol 80 series Landcruiser. We were off-road powered only by solar and the car most of August and September and had no idea there were battery problems. It was while we were in the caravan park at Cairns using a powered site that the iverter technician discovered the batteries were boiling. It was suggested by someone that if one cell in one of the batteries was dead it could cause the charger to continuously charge. We took the van to a battery & solar power specialist in Cairns who tested the batteries on two separate occasions and said there was absolutely nothing wrong with the batteries or any of their cells. At Airly Beach we left the van on a powered site while we went out to the reef and when we got back the seat above two of the batteries was so hot you couldn't sit on it. We went to an auto electrician in Mackay and he checked the battery charger and said there was nothing wrong with it. We took the batteries to the A/C Delco agent in Sydney who said the electrolyte level was low and they might come good with a long trickle charge. We gave them one but they did not respond. We are now waiting until we are ready to take off again before buying new batteries but would really like to sort out what is going wrong as we don't want to ruin the new lot. Has anyone got an idea of what is the problem? We were told all sorts of stories - 'batteries only have a short life anyway'! (Ours were about 1.5 yrs old). Can anyone recommend a good battery and a good charger? We are hoping to make it to Cania Gorge. So may meet you all at last. Pam & Geoff.
AnswerID: 559200

Reply By: Deleted User - Tuesday, Jul 22, 2003 at 07:40

Tuesday, Jul 22, 2003 at 07:40
Pam & Geoff

Quick response.

Once past 65% or so charge, a battery will gas - there will be/should be some bubbling - but not 'boiling'.

Best/safest way to check if OK is temperature - max safe is 50 degrees C (feels quite hot to the touch).

Another is water consumption - should use about 1 cm every 8-12 weeks. If less, is undercharging - if much more, is overcharging.

VERY strongly advise you buy a good (Mastervolt, Ample Power etc) three-step charger. Will cost $300 upwards - a lot upwards for a big one - (if it's less than that don't buy it). Will safe you a packet on batteries. .

Battery technology is pretty basic - all well-known brands work fine but avoid cheapies and Asian cheapies particularly. Always buy from a large store with high turnover as many batteries are all but wrecked just sitting around in the dealer's store uncharged.

Life of batteries is hugely a function of how well they are charged - and how deeply and how often they are discharged. They like the former - dislike the latter. This translates to typical 2-3 years but 5 - 7 is achievable (my OKA's lasted 7). In big domestic systems up to 14 years is not unusual.

Trust this helps
Collyn Rivers
AnswerID: 559201

Reply By: Andy1 - Tuesday, Jul 22, 2003 at 07:41

Tuesday, Jul 22, 2003 at 07:41
Geoff & Pam After much playing around we have come to the conclusion that we have a battery problem. I fully charged each of the three batteries last week & replaced the the tops, which I had removed to top up the electrolyte & for charging. All were showing the "green" dot. We have been away for six days & when I checked this morning each battery is holding charge at about 12.75 volts but there is a puddle of electrolyte around the tops of one or two cells on each battery & gassing is taking place despite the charger having been off for at least a week. Before anyone asks, the cells have not been over filled with electrolyte. Collyn may have an explaination. Anyway this effect in conjunction with the heavy gassing from some cells during charging which results in a mist of acid in that area, has convinced us to bite the bullet & replace the batteries with the type currently being supplied. I do not see BT as directly at fault but to me this whole issue does emphasise the need for this forum - if it was supported by BT to the extent that each past & current BT purchaser was notified & we had more members these issues would be nipped in the bud much earlier to the benefit of all. Many BT owners seem to be having problems with this type of battery but those with the new type seem quite OK. With regard to having adequate 12v - we spent a week or so on the Common at Innaminka last year & although it was August it was pretty warm & we struggled to keep the fridge cold without running out of power - went into amber most nights & the system shut down on low voltage one night. For this reason we are moving towards the fitting of the Anderson Plug to make use of the F250 200 Amp alternator & also, as mentioned earlier, plan to fit a more sophisticated battery charger & of course carry the Honda 10i as another backup. The trouble with solar is that in places like Innaminka et al the best spots are often partly shaded & this has one hell of an impact on charging. Hope to see you at Cania. Andy
AnswerID: 559202

Reply By: Noosa Fox - Tuesday, Jul 22, 2003 at 07:42

Tuesday, Jul 22, 2003 at 07:42
Andy, Have you spoken to Tracey or Steve about your battery problems as they may be covered under warranty. I thought that the AC Delco batteries had several years warranty with them. I know I had mine replaced under AC Delco warranty at just under 12 months old. Brian
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AnswerID: 559203

Reply By: Andy1 - Tuesday, Jul 22, 2003 at 07:43

Tuesday, Jul 22, 2003 at 07:43
Brian All sorted thanks - BT were very helpful. Colleted batteries yesterday & will be fitting today. Warranty only 12 months. Andy
AnswerID: 559204

Reply By: Deleted User - Tuesday, Jul 22, 2003 at 07:44

Tuesday, Jul 22, 2003 at 07:44
Check the voltage directly across the fridge when it's working. It should be within 0.3 of a volt of that across the battery supplying it. Virtually every 12-volt fridge fault is traceable to too-low voltage. The cable needs to be surprisingly heavy. If you need more info it's all in my electrical books: or post the total cable length and fridge draw here and I'll tell you what cable size you need.
Collyn Rivers
AnswerID: 559205

Reply By: Deleted User - Tuesday, Jul 22, 2003 at 07:45

Tuesday, Jul 22, 2003 at 07:45
A little good news:
Let me confirm what is often being said about
fridge cooling, relative to voltage drop:
I checked my voltages with fridge running, battery
= 13.15 V, circuit breaker = 12.95V fridge = 11.83V
After I picked myself up I looked for the
bottleneck following the 6mm2 wire from the circuit breaker and found what looks
like a 3 - 4 mm2 wire about 120 mm long with a 20 A fuse in
the middle of it going to the compressor connection on the back of the
I replaced the miserably thin wire and would
you believe: battery = 13.0V , circuit breaker =
12.8V, fridge = 12.4V.

So much for professsional caravan

AnswerID: 559206

Reply By: Noosa Fox - Tuesday, Jul 22, 2003 at 07:46

Tuesday, Jul 22, 2003 at 07:46
David, You had better bring your testing equipment and tools along to Cania, It looks like a few modifications may be in order for the rest of us. Brian.
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AnswerID: 559207

Reply By: Deleted User - Tuesday, Jul 22, 2003 at 07:47

Tuesday, Jul 22, 2003 at 07:47
Dave, I'm not even game to check mine .... in case I have to run a bigger wire all the way back. Curiosity will get the better of me sooner or later !!! All caravan manufacturers are what I term "SS" construction .... comes from me dealing with people at marine dealerships ( when I was into boats) and the work they do putting boats and motors together. Stands for "Silicone and Screwdriver" if the problem cant be fixed by either of these two they are at a loss .... most times backed up by a hammer. Words like .... Micrometer, Nutcert, Wiring length voltage losses, X-ray quality Welding chassis or frame, Torque Wrench, Taps and Dies, Electrolysis between dissimilar metals in contact, Wiring Diagrams, Shock Absorbers on Springs, Nyloc nuts etc are few and far between. Words like ...... PK Screw, Power driver, Glue, Thin plywood, Cheap Pine, Cheap Vinyl, Token Spray of black underbody, Tek Screws, Thin sheet metal, Wooden Battery boxes with lids PK screwed on by 4 screws to hold 75 kg of battery etc come to mind. I spent more than two years looking for a van to buy and came to the conclusion that BTs are the best apple in the barrel but every apple in the barrel is bruised to some extent. [wink] Regards Anthony
AnswerID: 559208

Reply By: Deleted User - Tuesday, Jul 22, 2003 at 07:48

Tuesday, Jul 22, 2003 at 07:48
I agree entirely Anthony, when was the last time
you saw a mechanic or tyre monkey use a torque wrench ? Let my cheap
experience be a warning to all of you. I'll be happy to check voltages
on all your vans, for me the remedy was short, sweet and cheap however
it may not be so for everyone. I'm easy to find, arriving Sept 2 with the
unorthodox looking BT front and back.
AnswerID: 559209

Reply By: Deleted User - Tuesday, Jul 22, 2003 at 07:49

Tuesday, Jul 22, 2003 at 07:49
I've taken the liberty (read interim managers perogative) to shift this to its own thread as I think it (fridge voltage losses) needs more discussion and comment under its own heading. Regards Anthony
AnswerID: 559210

Reply By: Luvntravln - Tuesday, Jul 22, 2003 at 07:50

Tuesday, Jul 22, 2003 at 07:50
Hi I am going to bring this back to the surface since I have had 13 years experience with the Sonnenschein Dryfit Solar Block Gel batteries. I had 4 - 8Ds on my boat. Two upright and on a tray in the dry bilge area under the cabin sole; two on their sides and under one of the setee seats. I had sophisticated charging and monitoring equipment for use when at the dock; i charged with my engine alternators when powering. I had various combinations including two 60amp golf cart battery chargers. The key was to carefully watch the voltage meter! They were and are great batteries and will take significant abuse with minimal life damage. Sometime we didn't want to listen to a charger so we might use 70 - 80% of their capacity and then high charge them to 13+ before backing off on the chargers. The key is to vatch the voltage meter!!! We will definitely opt for the Sonnenschein Dryfit Solar Block Gel batteries. Need to check the prices as these are also sold at most marine stores. Also look in the electronics section of marine stores for chargers and other 12V items. We were electrical pigs and will be again. A home on wheels needs to be lit and if you are concerned with using two many amps for your system - don't limit yourself; get another battery and more charging capacity. We had a 3000 wt Heart inverter/battery charger and would run the 110v microwave off of the batteries through the inverter. Can only do this when the batteries are fully charged. Happy lighting! Jay
AnswerID: 559211

Reply By: Deleted User - Tuesday, Jul 22, 2003 at 07:51

Tuesday, Jul 22, 2003 at 07:51
Re gel cells - these are excellent batteries and Sonnenschein is one of the best. Just a brief warning though that these batteries are very voltage sensitive. They absolutely must not be allowed to go over 14.4 volts whilst on charge and 14.1 volts is much safer, and 13.8 volts is adequate. If sspending this sort of money very strongly recommend you buy a smart charger that has a gel cell setting (Almost all do). But do note - the makers now say they should be located in a well-ventilated enclosure! Any orientation you wish - but not upside down. Collyn Rivers
AnswerID: 559212

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