Warning: strpos() expects parameter 1 to be string, array given in /volume1/web/wordpress/wp-includes/blocks.php on line 20 Warning: strpos() expects parameter 1 to be string, array given in /volume1/web/wordpress/wp-includes/blocks.php on line 20 Warning: strpos() expects parameter 1 to be string, array given in /volume1/web/wordpress/wp-includes/blocks.php on line 20 {"id":3330,"date":"2018-11-10T17:32:32","date_gmt":"2018-11-10T17:32:32","guid":{"rendered":"https:\/\/www.worldofwills.uk\/Home\/?p=3330"},"modified":"2021-01-15T10:09:17","modified_gmt":"2021-01-15T10:09:17","slug":"motorhome-batteries","status":"publish","type":"post","link":"https:\/\/worldofwills.uk\/wordpress\/2018\/11\/10\/motorhome-batteries\/","title":{"rendered":"Motorhome batteries"},"content":{"rendered":"\n

There is a lot of \u201cdiscussion\u201d in forums about the type of battery that should be fitted in a motorhome, and why some types are deemed to be unsuitable. In order to help me decide on which battery to buy to replace our existing battery I have pulled together the following information.<\/span><\/p>\n\n\n\n

Summary of battery types<\/b><\/span><\/h3>\n\n\n\n

Wet lead acid<\/b>: traditional old fashioned wet cell technology. Charging the battery heats the electrolyte and causes gassing.These batteries must be maintained by topping up with distilled water. They must also be vented and should NOT be mounted inside a motorhome. As the electrolyte is a liquid, wet cells are more susceptible to vibration. Some are sealed so shouldn\u2019t require topping up. Electrolyte is liquid so can spill in a crash.<\/span><\/p>\n\n\n\n

EFB: Enhanced flooded battery: <\/b>A step up from the wet cells, still a wet cell battery but does not need topping up. Supposedly sealed but still should be vented. Electrolyte is liquid so can spill in a crash and they will be susceptible to vibration. Charge regime as per wet lead acid battery.<\/span><\/p>\n\n\n\n

Absorbed Glass Matt (AGM): <\/b>this is the most contentious battery type. It was introduced as a completely sealed, high power, deep discharge, rapid charging, high performance battery. They are less susceptible to vibration as their electrolyte is encapsulated in the glass matt. AGM batteries are fully sealed and do not need venting. They can be mounted inside the motorhome.<\/span><\/p>\n\n\n\n

Gel: <\/b>Gel batteries are another deep discharge, rapid charging battery type that are completely sealed. Due to their construction, gel batteries can be mounted at any angle or orientation and are suitable for mounting inside a motorhome.<\/span><\/p>\n\n\n\n

Gel batteries perform better than AGM when deep discharged, meaning that they will provide a greater number of recharge cycles, they perform better at higher temperatures than AGM and are less sensitive to thermal runaway.<\/span><\/p>\n\n\n\n

Gel batteries recharge much faster than flooded-cell batteries, provided that a regulated charge voltage is temperature compensated, but cannot be charged as quickly as AGM.<\/span><\/p>\n\n\n\n

Gel batteries are extremely sensitive to charge voltages above 14.1-volts DC at 68 degrees.<\/b><\/span><\/p>\n\n\n\n

There are many posts in the forums from people whose batteries have failed after 1 or 2 years and many blame the AGM technology. <\/span><\/p>\n\n\n\n

My current battery is a Banner AGM. It is 5 years old and still retains its charge. My \u201cusage pattern\u201d is one of low rate of discharge – we have LED lighting and rarely use the TV; we also keep it on trickle charge when the \u2018van is parked at home. We have not gone off-grid for more than 3 days at a time, the last time being in the New Forest in October where we needed lighting, water pump, satellite (radio) and heating. The battery discharged to 12.3volts by the end of the 3 days and was showing as fully charged by the time we arrived home, less than an hour\u2019s drive away. <\/span><\/p>\n\n\n\n

Much of the \u201cnoise\u201d around the suitability of AGM batteries seems to be that they are unsuitable if you cannot charge the battery at 14.7V. The following graphic is from the Victron site and clearly shows that the normal charging voltage for an AGM battery should be between 14.2 and 14.6 volts. The \u2018van\u2019s alternator voltage is 14.4 and the EBL is capable of 14.4V which fall in the normal service charge range for an AGM battery. <\/span><\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

From the Victron table above it looks like 14.6-14.9V is needed to perform a fast recharge of the battery as opposed to a \u2018normal\u2019 recharge.<\/span><\/p>\n\n\n\n

Banner specify a maximum<\/strong> charging voltage for AGM at 14.8V.<\/p>\n\n\n\n

An AGM is capable of a fast recharge which would mean supplying 14.6-14.9 volts.<\/span><\/p>\n\n\n\n

An AGM has very low internal resistance allowing it to be charged very quickly. Low internal resistance combined with a low state of charge and applying >14.4V will lead to a high current charging so will necessitate using a charger capable of providing around 25% of the battery rating to adequately charge. For a 100Ah battery, the charger should be rated at least 25A. <\/span><\/p>\n\n\n\n

Low internal resistance also leads to better high current discharge rates than wet cell batteries hence exhibit a greater number of charge-discharge cycles.<\/span><\/p>\n\n\n\n

AGM batteries require precise, voltage-regulated, temperature-compensated charging routines. AGM batteries can<\/b> accept a very high charge rate, a charge rate unlikely to be provided by most van battery chargers. Chargers should be connected to a battery mounted temperature sensor to prevent thermal runaway.<\/span><\/p>\n\n\n\n

Gel: <\/b>Gel batteries are another deep discharge, rapid charging battery type that are completely sealed. Due to their construction, gel batteries can be mounted at any angle or orientation and are suitable for mounting inside a motorhome.<\/span><\/p>\n\n\n\n

Gel batteries perform better than AGM when deep discharged, meaning that they will provide a greater number of recharge cycles, they perform better at higher temperatures than AGM and are less sensitive to thermal runaway.<\/span><\/p>\n\n\n\n

Gel batteries recharge much faster than flooded-cell batteries, provided that a regulated charge voltage is temperature compensated.<\/span><\/p>\n\n\n\n

Gel batteries are extremely sensitive to charge voltages above 14.1-volts DC at 68C.<\/span><\/p>\n\n\n\n

Notes<\/b>:<\/span><\/h2>\n\n\n\n