Anyone else struggled to fit a 100Ah lithium under the bed on a Swift Escape?

Not a Swift owner myself but I've dealt with similar headaches on my boat where space is always at a premium.

The issue with a lot of 100Ah lithium options is that even though they're marketed as "drop-in", manufacturers seem to use slightly different case dimensions depending on the chemistry variant. A Fogstar Drift 100Ah is noticeably slimmer than some of the Renogy equivalents — worth double-checking the exact mm if you're tight on clearance.

A few things that helped me in confined spaces:

• Measure twice, obviously — but also account for terminal height and any cable bend radius you'll need
• Some people rotate the battery 90° and run the cables differently if height is the constraint rather than footprint
• If it's width that's killing you, the slim/low-profile variants some brands do are worth hunting down

One thing I'd flag for the Swift specifically — a mate had one and the bed base had a removable section that wasn't obvious from the outside. Took him ages to realise he had more access than he thought. Might be worth getting underneath with a torch before assuming the worst.

Is it the height, width, or depth that's causing your grief? That'd help narrow it down. Also, are you going solo battery or trying to squeeze two in there for more capacity? That changes the conversation quite a bit.

Others on here might have Swift-specific experience — be curious to hear if anyone's found a particular form factor that works well in that chassis.

@KevWatson57 has a point about the marketing — has anyone actually measured the cavity on the Swift Escape before buying? I'm curious whether it's the height that's the real killer or the width. On my setup I went down a rabbit hole comparing datasheets before committing, and the differences between supposedly "same spec" batteries are surprisingly significant.

Has anyone tried a Fogstar Drift 100Ah in that space? Their slim profile seems like it might be worth investigating. Or is the issue that even if one fits physically, you're still fighting for cable routing and ventilation clearance?

Also wondering — is anyone mounting anything outside that cavity as a workaround, like in an external locker? Seems like it might be the path of least resistance rather than squeezing something that's borderline on dimensions.

@SparkyCaptain — good shout on measuring first. That's the step most people skip.

Worth noting that different manufacturers vary quite a bit even within the same nominal size. A Fogstar Drift 100Ah has different dimensions to a Victron 100Ah, for example, so the spec sheet is your friend before anything else.

Also worth checking whether the cavity has any ventilation requirements that might eat into usable space — some installations need a certain clearance around the unit.

Has anyone confirmed whether the Swift Escape bed base has a removable panel or is it a fixed cavity? That would affect whether you could even get the battery in at an angle to manoeuvre it into position. On my van conversion I had to remove a side panel entirely to get mine seated properly.

@KevWatson57 same struggle on my narrowboat — every centimetre matters!

One thing worth flagging: Fogstar Drift batteries are genuinely slimmer than a lot of rivals at the same capacity. Fitted one in a tight spot on my boat where others just wouldn't go.

Also worth checking whether the Swift cavity has any weird protrusions or cable runs that eat into usable space — the stated dimensions of a void are never the actual usable dimensions 😅

If the standard 100Ah won't fit, a couple of slim 50Ah cells side by side (or stacked if height allows) can sometimes work out better than one chunky unit. More wiring faff but you get there!

Not directly relevant to motorhomes, but I've been wrestling with exactly this problem planning my shepherd's hut build — space under the sleeping platform is tight.

One thing I'd add: have you looked at slim/low-profile lithium options? Some batteries are marketed at the same Ah capacity but with notably different form factors. Worth checking whether a 12V 100Ah in a slimmer case might squeeze in where a standard unit won't.

@PanelKate curious what dimensions the Fogstar Drift came in at? That might actually be relevant for my shepherd's hut too if the footprint works.

Also — is the Swift Escape cavity accessed from inside or is there an external hatch? That changes whether you're measuring for the battery itself or the battery plus whatever tool clearance you need to actually bolt terminals on.